Topics

Three Ways to Detect Small Air Leaks Around Doors
Ways to Seal Air Leaks Around Doors and Attic Hatchways
Five Types of Weather Strip for Doors and How to Mount Them
Door Sweeps and Weatherizing Door Bottoms
Door Thresholds
Insulate Doors By Repairing Doors and Door Frames

 


You can make any door air-tight by using a combination of weather stripping along the sides and top, and a door sweep, weatherizing door bottom, or insulating threshold. You may need to test more than one product to see which insulates best, and you may need to buy one or two inexpensive hand tools. You should do the work yourself because hiring a person may cost more than you save in energy bills, and if you do it yourself, you can re-do it when the materials wear out. The door jambs or door stops on the sides and tops of the door frame may need to be repaired.

If you live in an upper floor condo or apartment, insulate the front door to the building. In the heating season, cold air that leaks in around the front door will rise to your unit like warm air going up a chimney.

This web page shows you how to insulate many types of doors. It shows how to repair them if they leak because the door frame or the door is rotted or in other ways damaged. I found this information from my experience in weatherizing and repairing doors, and from seeing weatherization that had been done on doors I was repairing, and from reading do-it-yourself websites.


Three Ways to Detect Small Air Leaks Around Doors


If possible, check for leaks on a cold winter day or a very hot summer day so the tests will then show very small leaks.

      • Move an incense stick along the side, top and bottom edges of each door to detect air flowing into or out of your house. If the smoke does not rise straight up, there is a leak. A candle is less effective.
      • Tape a thin plastic sheet over each door. It will billow inward if air is leaking into the house, or cling to the door if air is leaking out.
      • The most accurate way is with an “infrared thermometer”, also called a “non-contact infrared thermometer”. These measure temperature by measuring infrared radiation, which transfers heat energy. They detect cold spots in winter and warm spots in summer.

        Home centers have them, at a wide range of prices and qualities. Using this, you can measure the temperature around each door to check for cold spots in the heating season and hot spots in the cooling season. It can also be used to check windows and basement walls. 

 

Ways to Seal Air Leaks Around Doors and Attic Hatchways

Basement Doors are the Most Important Doors to Insulate Due to the Chimney Effect

When air is heated it becomes lighter and rises like hot air in a chimney. This is called the “chimney effect”. When the air in your home is being heated in winter, it rises to the attic and escapes through the attic vents. This causes the air pressure in the basement to be lower than on the other floors, causing air to be drawn in very forcefully from under or around the basement doors. The air pressure on the first floor will be slightly lower than the outside air pressure, so air will leak in, but less forcefully. The air pressure on the second floor will be very close to the outside air pressure, so almost no air will flow through second floor doors, such as balcony doors in winter, except when the wind blows. Then, air will be drawn out.

How to Seal Air Leaks Caused by Loose Door Latches

      • If air leaks through at the sides or top of a door, close the door tightly and test it again. If this stops the leak, you may be able to remount the latch strike plate to make the door close more tightly to seal the gap. To remount a latch strike plate,
          1. Remove the latch plate and fill the holes tightly with pieces of wood shaved from scrap wood.

          2. Drill pilot holes and remount the strike plate.

          1. If you must slam the door hard to seal the air leak after remounting the latch, re-mount it or buy an adjustable strike plate, which allows you to “fine tune” the adjustment. These are available at locksmith shops, home centers and hardware stores.

        1. If you have a deadbolt lock with a horizontal deadbolt, check if it still closes easily. If not, take off the strike plate and file out the hole in it to make it larger.
      • If you have a lock with a vertical-sliding bolt ( interlocking door deadbolt)  you may be able to adjust it by remounting the piece mounted to the door frame.
      • If the latch strike plate is loose, try using longer screws. If the doorjamb is cracked where the screws enter, put in 2“ screws that will enter the frame behind the doorjamb.


How to Seal Air Leaks On Doors That Have Weather Stripping  

      • If vinyl or rubber weather strip has been painted, replace it. It may have lost its flexibility.
      • If spring bronze (spring metal) weather strip is wrinkled, replace it. If it has large paint drops, scrape them off. 
        If it is wrinkled, you could leave it on and mount weather strip to the surface the door strikes (the doorstop). To replace it or to mount weather strip to the door jamb, see Five Types of Weather Strip for Doors and How to Mount Them
      • If aluminum strip with vinyl bulb weather strip allows air leaks, remount it closer to the door. Drill new holes through the aluminum strip. If you drive the nails or screws through the original holes, they will enter the wood next to the old holes in the wood and fall back into these holes and the weather strip will move back into its original position.
      • If weather strip that fits in a slot in the doorjamb (kerf-fitted) is badly worn, replace it. Pull it out and push in a new one. If the door is metal, kerf-fitted weather strip may be attached magnetically. These types are available at home centers and can be ordered from the manufacturers.

        If it has lost its stiffness but is not badly worn, make it stiffer by coating its inside surface with construction adhesive. If it has contracted in length, leaving a gap at the bottom, seal the gap by cutting a small piece of foam pipe insulation and gluing it in.

How to Insulate Storm Doors

      • Install a storm door at your front doorway if it would beautify your home in addition to saving energy. the energy savings alone would not justify its cost. Most modern storm doors cost from $150 to $350, plus installation. You can install one yourself if you are an experienced do-it-yourselfer. 

      • If you have a storm door with a door closer, check that it latches when the door closer pulls it shut. Check it with the primary door closed because the air pressure will be higher, which could cause it to not close. If the storm door does not latch, turn the adjustment screw to make it close slightly more forcefully. 

        If it still does not latch, check if its hinges are loose. Storm doors may have a “piano hinge”, which is the length of the door, or may have 4 hinges. Both types of hinges are screwed to a thin aluminum frame, and they often come loose because aluminum is softer than steel, so the threaded areas become damaged more easily than steel. If the threads are damages, replace the screws with slightly thicker screws. You may be able to use a few long screws and screw them into the wood

      • Check that the storm doors close tightly against the weather strip in the frame.  If there are gaps, the storm door’s frame may not have been mounted to the doorjamb correctly. Loosen the screws that mount the frame to the doorjamb, insert shims and re-tighten the screws. If this creates gaps between the frame and the doorjamb, caulk the gaps.
          
      • If a storm door contacts the weather strip at the top but not the bottom, install a second door closer at the bottom. Many storm doors have two door closers to prevent infiltration.

      • If a storm door closes hard but does not latch, adjust the strike plate. 

      • Check if the storm door’s door sweep or insulated door bottom contacts the surface below it, and lower it if it doesn’t. If the door sweep or insulated door bottom drags along the ground, raise it to 1/16” above the ground to prevent it from tearing.

      • Check if any of the fins on the bottom of the storm door are torn. Replacement fins are available in the weatherization department of some home centers and hardware stores. If a vinyl fin is not available, mount a finned storm door bottom or a conventional door sweep. This may be acceptable for a rear door but it is probably too unattractive for your front door. Replacement fins can be ordered.



 

      • Modern storm doors have thin brush-like strips called “pile weather strip” along the sides and top. If your storm door has this, check if any is missing or worn. Home center may carry one size, called “storm door pile weather strip”.

      • If you have a storm door with a removable glass or vinyl panel, check if air leaks in around the edges of the panel. If so, tighten the panel’s mounting clips.

      • Seal the gaps between the glass slats on jalousie storm doors. Some stores sell “jalousie jackets”. Theses are clear vinyl sleeves that fit over the edges of the louvers to make them air-tight when closed. You could, instead, apply “removable insulation”. This peels off in one piece without leaving stains. It is sold in the paint departments of home centers and hardware stores.


How to Insulate Attic Hatches

 

      • If the entrance to your attic is a hatch, seal the gaps around its edges. A hatch entrance normally has a thin board as a door, without hinges. In the heating season, warm air rises forcefully into the attic through gaps around the hatch door and leaves the house through the attic vents. This is due to the “chimney effect”.

        In the cooling season, very hot attic air escapes through the attic vents, forcefully drawing air conditioned air up into the attic through gaps at the hatch. If the door is not warped, mount EPDM weather strip to the wood the door rests on. See EDPM cellular rubber weather strip tape If the door is warped, flatten it by screwing boards onto the top of it.

        1. Cut pieces from a 1”x10” board to cover the hatch door.
        2. Mount them to the top of the door using 1¼” drywall screws, putting the screws through the door into the boards. Use many screws to prevent the door from warping perpendicular to the boards.
        3. Cover the screws with joint compound, using a 4” or 6” taping knife. Sand it when dry, and paint the door.

      • If a hatch door is warped and you will not straighten it, insulate it with self-adhesive rubber foam weather strip tape. This has several names, such as ”foam window seal”. It compresses more than other weather strip materials, and is available in thicknesses of up to 7/16”. Only “low density” rubber foam weather strip tape is very compressible. It may have to be replaced in a few years. Prepare the surfaces it will stick to by sanding or scraping them. After sticking it on, staple its ends or nail them with 3/4 “wire nails. 

      • If you have a hatch and your attic floor is insulated, mount a piece of insulation to the top of the hatch door. If you have a scrap piece of fiberglass batt insulation, cut a piece from this to use. If not, buy a 16” wide roll of multi-purpose fiberglass insulation. It is only R-3, so nail on two or three layers to match the insulation on your attic floor.

      • If the entrance to your attic is a hatch with pull-down stairs and the door doesn’t close tightly, try to repair the stairs or closing mechanism before sealing the gaps with weather strip. You can often repair it by tightening the bolts. If it was poorly installed you may need to remount the closing mechanism or hinges. Repairing it is better than sealing large gaps with thick weather strip because this is not durable. 

      • If the entrance to your attic is a hatch with pull-down stairs and the door closes tightly, mount weather strip if there is none. Use EDPM cellular rubber weather strip tape. Carefully prepare the surfaces that you will stick it to by scraping or sanding them. After mounting the weather strip, staple down its ends with 5/16” or ¼” staples.

        If gaps are too wide for the weather strip, glue 1/2“ wide strips of wood to the surfaces of the door that the weather strip will contact. The strips could be cut from paint stirring sticks using a utility knife. After gluing them into place, nail in 1” brads or 1” wire nails to hold them until the glue dries.

        Instead of using strips of wood, you could use rubber foam weather strip tape. This compresses more than other weather strip materials. It is available in thicknesses of up to 7/16”. Only “low density” rubber foam weather strip tape is very compressible. It may have to be replaced in a few years.

      • If the entrance to your attic is a hatch with pull-down stairs and the door closes tightly and there is weather strip, check if it is sealing tightly. You can’t see the weather strip when the hatch is closed, so it is hard to check for a gap. One way is to paint the frame where the weather strip will contact it, and then close and open the door. Where ever the weather strip does not get paint on it, there is a gap. You can wash off the paint before it dries.

        Another way is to close the door with a sheet of paper between the frame and the weather strip in many locations around the frame. Where ever you can slide out the paper without effort there is a gap.

        Replace the weather strip with thicker material if there are gaps. Use self- adhesive “D-Shaped” EPDM rubber weather strip, which is a very durable material. It has several names, but all brands are D-contour and labeled EPDM. This is a rubber material designed for weatherizing.   

        crape or sand the surfaces the tape will be stuck to for good adhesion. After mounting the weather strip, staple down its ends with 5/16” or ¼” staples. If gaps are too wide for this weather strip, glue 1/2 “wide strips of wood to the surfaces of the door the weather strip will contact. The strips could be cut from paint stirring sticks, using a utility knife. After gluing them into place, nail in 1” brads or 1” wire nails to hold them until the glue dries.


How to Insulate Exterior Double Doors

Exterior double doors can only be air-tight if one of the doors is held in place by slide bolts at the top and bottom. This door will have a strip of molding attached, which is a doorstop for the other door and has weather stripping.

      • If air leaks in or out between the doors because there is a gap between them, check if one of the slide bolts is not closed. If it is very hard to close, re-drill the hole, but don’t make it larger or the doors will not close tightly enough.

      • If air leaks between the doors, check that they are perfectly aligned with each other from top to bottom. If not, check if one of the holes that the slide bolts slide into should be moved slightly.

      • A gap between the doors could be caused by the latch not pulling the doors tightly together. You can correct this by slightly relocating the strike plate. Remove the strike plate, and then fill the two screw holes with slivers of wood. Drill pilot holes for the screws and remount the strike plate.

      • If the gap between the doors is only at the top or bottom because one of the doors is warped, and one slide bolt hole has been re-drilled to allow for it, seal the gap with  self-adhesive rubber foam weather strip tape. This has several names, such as ”foam window seal”. It compresses more than other weather strip materials, and is available in thicknesses of up to 7/16”. Only “low density” rubber foam weather strip tape is very compressible.

        Prepare the surfaces it will stick to by sanding or scraping them. After sticking it on, staple its ends or nail them with ¾” wire nails. 

How to Fix Doors That Are Hard to Close

      • Check if the hinge screws are loose. If they are loose, try to tighten them. If you cannot tighten them because the wood is slightly rotten, replace them with 2½” screws. These will fasten the hinge to the wall stud behind the jamb. You may have to drive some of them in at slight angles.

      • If there is brick or block behind the doorjamb, (not wooden framing) and screws won’t tighten because the wood is slightly rotten, move those screws to different locations on the hinges by drilling holes in the hinges.

      • If the door doesn’t close well because its edge rubs against the doorjamb, use a plane, a rasp (wood file), belt sander, or wood shaver to remove wood from the door.

      • If necessary, remount the strike plate. Remove it, fill the holes with wood slivers, and drill pilot holes. Remount the weather stripping.

 

How to Replace Broken Glass 

      • If a pane of glass in a door is cracked, replace it. On exterior doors, the panes are normally held in by strips of wood beading) rather than glazing putty. If it is held in by strips of wood:

STEPS:

        1. Lay a drop cloth at both sides of the door to catch small pieces of glass.

        2. Use a utility knife to cut the paint around the strips of wood.

        3. Using a hammer and a stiff 1” putty knife, pry off the strips of wood (beading). This should be done before you buy the glass so you can measure the dimensions accurately. Save the wire brads to re-use.

        4. Buy the pane of glass.

        5. Use a nail set or a flooring nail to nail in the wire brads. Flooring nails are square with flat heads. Tap in the nails carefully. If you have large slip-joint pliers, use these to squeeze the nails into the wood in place of nailing them to prevent breaking the glass. 

        6.  Caulk around the strips of wood, and paint the caulking after it dries. 


How to Insulate a Warped Door

If there is a large gap at the bottom corner of a door because the door is warped, there are several ways to seal the gap. Rubber foam weather strip tape is not included because it is not durable.

      • If the door is warped because it was designed to be used as an interior door, it will only warp further. These doors are hollow or have thin floating panels. It would be best to replace the door. If it won’t be replaced, lay it down and flatten it and screw on a 2”x6” board to keep it flat.

      • If a warped door closes against doorstop molding that is nailed to the doorjamb, remove this molding on the latch side and replace it with weather strip doorstop molding. This can be mounted in a slightly curved pattern to fit a warped door. These are wood doorstops with vinyl weather strips inserted in them. 

      • If a warped door is in a doorway with a notched door jamb rather than a doorstop nailed to the doorjamb, there are two methods for insulating it. 

        • One method is to mount a short piece of bronze spring metal on the bottom of the doorjamb. The edge of the door will compress it to seal the gap. This is the only durable type of weather strip that is designed to contact the surface edge of a door. If the door becomes more warped, the spring metal will still seal the gap.

        • The second method is to insert a thin piece of wood between the surface the door contacts and the weather strip. 

                               STEPS:

        1. Buy a package of 1”x 12” shims.
        2. Cut a shim to ½ “ wide using a utility knife.
        3. Scrape off the paint and glue on the piece of wood.
        4. Nail it and the weather strip onto the door with 1” wire brads or 1” wire nails.

      •  

How to Insulate Sliding Patio Doors

      • Seal the gap under a sliding patio door. One way is to lay a small carpet next to the door in winter with its edge rolled up against the doors. Another way is to cut out a long, thin rectangle of cloth, roll it into a cylinder, sew its edges together and stuff in rags or polyester fiberfill. Lay it on the floor to seal the gap. Another way is to cut a strip from an old, heavy rug to lie over the gap.

      • If you have sliding patio doors, inspect their weather strip. Modern patio doors have either pile or thin vinyl strip weather strip along all four edges of each door, either on the door or on the frame. Check if it is badly worn. Pile is available at home centers, but often in only one size. It is available in many sizes in window repair stores and can be ordered online from a pile weather strip manufacturer or from the patio door manufacturer. Vinyl weather strip can be ordered from the manufacturer.

      • If you have sliding patio doors, check that their side edges contact the doorjambs from top to bottom. If not, adjust the two wheels at the top of each door. If they were not designed to have weather strip, mount weather strip around them. Mount thin weather strip to the doorjambs to compress very flat when the doors are closed so the latch closes easily.

 

EPDM ribbed-profile weather strip could be used; it is durable, but may be too thick. It compresses to about 1/16” thick. Low-density ¼” thick rubber foam weather strip tape can be compressed to be paper-thin. See Rubber Foam Weather Strip Tape. For either type, prepare the surface it will stick to by sanding it.

      • If your climate is very cold, you could mount aluminum strip with vinyl bulb weather strip to the frame members above and below the patio doors, but it is unattractive. This would be screwed onto the frame, so it should last for many years. Mount it with self-tapping sheet metal screws. See Five Types of Weather Strip for Doors and How to Mount Them.

thinnest-space-shorter

      • If your climate is very cold and you have sliding patio doors that you don’t use often, you could cover them in winter with 12” wide strips of “foil and fiberglass duct insulation”, and then hang curtains or close your curtains to hide its appearance. It is available in the HVAC department of home centers. It is thin, but the foil increases its R-value by reflecting thermal radiation. Most types of rigid insulation cannot be used because they emit toxic gas in a fire if not covered by drywall.

      • If your air conditioning costs are high, you could cover your patio door glass with “heat control window film”. This is most effective if the patio doors allow direct sunlight into your home. Buy a window film that is described as “insulating”. The most effective type for lowering air conditioning use is “mirror reflective film”, also called, “mirror silver privacy film”. This appears as a mirror from outside of the home and prevents persons from looking in.

    • Insulating window film has several names, such as “heat-control window film” and “heat-blocking window film”. Avoid buying window film that is designed to prevent persons from looking in, not to block out heat, such as stained glass pattern window film, “frosted white privacy window film” and other decorative window films.

A product may appear to be insulating window film but isn’t if it is described by phrases such as, “blocks up to 99% of UV rays to help reduce fading”. These are not designed to block the heat because heat energy is transmitted more through infrared radiation than through UV radiation. These are designed mainly to prevent your furniture from fading. Buy a brand of film that has an installation video on the company’s website.


How to Insulate the Doors to Your Attic and Basement

If you heat your home many months each year, it may be worth your effort to insulate the doors to your attic and basement, because heated air flows up through the house and escapes through the attic vents.

 

      • Around the attic and basement doorways, mount white self-adhesive “D-Shaped” EPDM rubber weather strip, which is a very durable material. This is more attractive than other materials. It has several names, but all brands have a D-contour and are labeled EPDM. EPDM is a rubber material designed for weatherizing.     See EDPM cellular rubber weather strip tape.

        At the doorway to the attic, mount a ½” thick oak interior threshold and mount an attractive door sweep. See How to Mount a Threshold on a Wooden Floor Do not mount a threshold at the doorway to the basement because a person could trip on it and fall down the stairs.


        At the doorway to the basement, mount an attractive door sweep. 

Double draft stop
.    Double draft stop

      • If you don’t mount a threshold to the door to the attic, you could block the air with a “Double Draft Stop”, which is slid under the door. These are made of cloth, with two solid foam tubes, one for the inside and one for outside of the door. They are sold at hardware stores and home centers.


Other Ways to Insulate Doors

    •  

      • If a wooden door has a badly damaged edge that allows air to enter, repair it. Marine epoxy should be used for this because it is the most durable wood filler. Drill many short holes into the door where the epoxy will be applied to create a strong bond. Apply the epoxy, carefully following the directions.

      • If a door has a door sweep and no threshold, mount a threshold or replace the door sweep with a long-lasting aluminum and reinforced rubber door sweep. A threshold will prevent the door sweep from dragging on the floor and wearing out soon. See Door Thresholds and also, Door Sweeps and Weatherizing Door Bottoms.

      • If your garage can be very cold or if the garage door is often left open, insulate the door between your garage and the house. Mount weather strip to the sides and top, and mount a door sweep, weatherizing door bottom, or insulating threshold at the bottom.

      • If there is a gap under the garage door and it rests on a surface that is fairly level, seal the gap by mounting a “garage door bottom”. There are several types, some are designed to seal large gaps and some are only for small gaps. Below are two popular designs, the EPDM rubber garage door bottom and the aluminum and rubber garage door bottom. Both are shown upside down, and both are mounted to the bottom surface of a garage door.
      • If there is a gap under the garage door and it rests on a surface that is very uneven, with gaps too large for a garage door bottom seal, nail a piece of wood to the bottom of the garage door that is cut to fill the gap. This will insulate the garage and can prevent rodents from entering. 

STEPS:

        1. Buy one or two pressure treated 8 ft.  2″x4″  boards to fit across the garage door as far as needed. 
        2. Draw a cutting line across them, to cut them to roughly fit the contour of the surface below the garage door.
        3. Cut across the cutting line.
        4. Screw them onto the bottom edge of the garage door. Use long screws because the garage door wood may be weak from rot and because the door will be slammed onto it forcefully.
        5. Screw the insulating door bottom onto the bottom edge of the door.

      • Insulate the doorway to any room that is often warmer or cooler than the rest of the house, such as a room with a space heater or window air conditioner. This may be a room that you don’t often use, so you have closed the register or turned off the radiator. It may be a “sun room”, a room with a wall of windows, which is colder in the winter and hotter in the summer.

        This insulation should be attractive, so use white EPDM cellular rubber weather strip tape. Mount a ½” oak interior threshold and a multi-fin door bottom. If you won’t mount a threshold and door bottom, you could block the air with a “Double Draft Stop”, which you slide under the door (see picture above).

      • If you have an inner and an outer front door and members of your household leave the inner door open, mount a door closer on it to keep it closed.

      • If a mail slot cover doesn’t close, lubricate it, repair it, or replace it. Mail slot covers for very old mail slots are not often sold in stores because mail slots were smaller in the past. You could cut out a larger hole and install a modern mail slot using a reciprocating saw.

      • If your climate is cold and you have a mail slot in your front door, replace its cover with an air-tight cover. These are called “magnetic mail slot covers” or “energy-efficient mail slot covers”.

      • If you have a pet door that was not designed to be air-tight, replace it with an air-tight model. These are available at pet stores and some home centers.

      • If your climate is very cold and you have a pet door, fill the hole in the door with a piece of fiberglass insulation on cold nights. This is available in small rolls, 16” wide, as “pipe wrap insulation” .

      • If you have a pocket door (an interior door that slides into the wall) that does not close and you could close it to lower your energy costs, repair it. Remove the casing at the top of the doorway and check what needs to be repaired. One of the wheels may have fallen off of the track.

      • If the edge of a door in the area of the door latch is badly damaged, allowing a sizable gap, install a “backset lock and door reinforcer”. This is normally made of brass sheet metal. It wraps around the door, enclosing the area near the latch and doorknob. It is designed to strengthen the door against break-ins. They are available in brass and silver-colored finishes at home centers and locksmith shops.

      • If you have an insulating threshold with a vinyl insert and it makes the door hard to close, the vinyl insert will wear out too soon. Take down the door and bevel the bottom of the door with a belt sander or plane.

      • If you have a solid wood exterior door with “floating panels” that has a crack in the panels that lets air through, repair the panels. The door will look much better if you repair the panels than if you caulk the cracks. The panels were designed to expand and contract within grooves with changing temperature and humidity.

        Fill the crack with glue and slide one side toward the other to close the gap. If necessary, screw a 1″ screw into the panel you will slide and pull the screw with plyers.



Five Types of Weather Strip for Doors and How to Mount Them

It normally takes  trial-and-error to find the best weather strip for a door, in fact, the weather strip that works best for the top of the door is often too thin for the bottom of the door . The key is to buy a variety of materials and try several if necessary.

Type 1 – EPDM Cellular Rubber Weather Strip Tape

EPDM cellular rubber weather strip tape is self-adhesive  tape made from EPDM cellular rubber. This material is designed to keep its shape for many years, even in sub-freezing conditions.  It is normally the best type to use where the weather strip must be attractive. If it is the same color as the doorway, it is almost unnoticeable when the door is open.

It is available in white and brown, and in various shapes (profiles), each designed for a different gap thickness. Most of the profiles are hollow, designed to collapse to fill a range of gap thicknesses. It will stay in place for many years, but only if it is mounted to a clean and dry surface. It will stay longer if it is stapled or nailed at each end.

Medium size EPDM weather strip has a “D-profile” and fills gaps from 1/8” to ¼”; the thin size has a “ribbed-profile” and fills gaps from 1/16” to 1/8”; and the large size has a D-profile and fills gaps up to 5/16” thick. Brown EPDM is available in some stores, but normally only in one thickness.


How to Mount EPDM Cellular Rubber Weather Strip Tape to a Doorjamb

TOOLS AND MATERIALS:

        • Several sizes of 3/8” wide EPDM weather strip. Trial-and-error is necessary, so buy at least two sizes.
        • Sandpaper or sharp wood chisel.
        • Hair dryer (only if air temperature is below 50° ).
        • Wooden shims and construction adhesive (only if the weather strip will be mounted to shims where the gap is wide)
        • Utility knife
        • Staple gun and 5/16” staples, or ¾” wire nails. Note: wire brads are not acceptable.


Mount the Weather Strip:

        1. Do not mount the weather strip if the outdoor temperature is below 40º or if it has rained recently, as the instructions indicate. If the outdoor air temperature is above 40º but below 50° , heat the door frame with a hair dryer or wait for a warmer day. Also, it could be slightly damp from warm, inside air leaking out around the door and condensing on a cooler door frame. 

        2. On the latch side and at the top of the doorway, the weather strip should be mounted to the surface the door strikes. On the hinge side of the doorway, it should be mounted to the doorjamb, so that the edge surface of the door compresses it. 

        3. Sand the surfaces the weather strip will stick to, and wipe off the dust. This will clean it without getting it wet and will rough it up for better adhesion. If the surfaces have bumps from dried paint, scrape the surfaces with a sharp wood chisel.

        4. If the gap is greater than ¼” at the bottom of the door (because the door is slightly warped), build up the area with a shim before putting on the weather strip. Use a wooden shim from a package of shims and cut a strip 3/8 “ wide with a utility knife.

          Scrape the paint off of that area of the frame until it is bare wood, and glue on the shim with construction adhesive. Nail in two ¾” wire nails. If the gap is long, cut a 3/8” strip from a paint stirring stick and carve it to make it tapered, similar to a shim.



        5. If the gap is too narrow in places for D-profile weather strip and ribbed profile weather strip is not available, which is thinner, cut D-profile weather strip to make it thinner. Using scissors, cut off the curved part to make it about 1/6” thick.

        6. Stick on the weather strip on the latch side of the doorway and then check that the door latches easily and that the deadbolt or vertical slide bolt lock closes easily. If not, replace the weather strip with thinner weather strip. If a deadbolt or vertical slide bolt lock is hard to close a key could break.

        7. Mount weather strip along the top hinge side of the doorway and check that the latch and lock close easily.

        8.  If the door has a deadbolt lock and it becomes  slightly harder to lock, remove the strike plate and file the hole to make it larger.

        9. Staple the ends of each piece of weather strip with 5/16” staples, or nail in ¾” wire nails.

 
 

Type 2 – Weather Strip Door Stop Molding

Weather strip door stop molding has a vinyl fin inserted in a strip of wooden molding.  It can be more durable than self adhesive EPDM weather strip tape, but is unattractive when mounted to a doorjamb. 

If a door is warped, you can seal the gap by mounting a weather strip door stop to fit the curvature of the door.


How to Mount Weather Strip Door Stop Molding

Weather strip door stop molding has a strip of weather strip inserted in a strip of wooden molding. They are not attractive when mounted onto a doorjamb, but are attractive when used to replace a door stop. If a door is warped, you can seal the gap by mounting weather strip door stop molding to fit the curvature of the door.

STEPS:

 

        1. If there is  door stop molding, remove it. Cut the paint along both sides with a utility knife and pry it off with a stiff putty knife.

        2. Measure the door frame and cut the pieces of weather strip door stop. A hacksaw or small wood saw will cut the wood neatly and a knife is best to cut the weather seal.

        3. Paint the pieces with exterior paint. Paint the end surfaces thoroughly for protection from rot.

        4. Nail the molding to the latch side of the doorway using 2″ galvanized finish nails after pushing the door inward as far as it will go. Most doors move about 1/8″ when latched.

          Hammer each nail only half-way in so it can be removed if you move the molding. Nail in a few nails and check if the door still locks easily. This won’t be necessary when nailing the molding to the top and hinge sides of the doorway.

        5. If the lock has a horizontal slide bolt and it is hard to close after mounting the weather strip, remove the striker plate and file it out to make it larger.

        6. If the lock has a vertical-sliding bolt (interlocking door deadbolt), it may be very hard to adjust if it doesn’t close well after the molding is nailed on. Carefully choose the best thickness of weather strip to prevent this problem. 

        7. Hammer the nails in below the surface using a nail set or square cut nail and cover the holes with exterior caulk.

        8. Caulk where the molding meets the doorjamb.

        9. Nail strips of molding to the hinge side and the top of the doorway. It may not be necessary to hammer the nails only half-way in and close the door to check it after every few nails because the door compresses the weather strip more forcefully on these surfaces.


Type 3 – Aluminum Strip with Vinyl Bulb Weather Strip

This type of weather strip has no standard name, its manufacturers have different names for it, such as “doorjamb weather strip”. It is made of a rigid strip of aluminum and a vinyl bulb. The rigid strip is screwed to the doorstop or to the doorjamb if there is no doorstop, at a position where the vinyl bulb is compressed by the door when it closes. It is unattractive, but probably suitable for rear entrances and basement doors. It is popular because it is more durable than any type of self-adhesive weather strip.


Mount Aluminum Strip with Vinyl Bulb Weather Strip

 TOOLS AND MATERIALS:

        • Hacksaw
        • Tape measure
        • Drill
        • 3/32” and 1/8” drill bits
        • Package of aluminum strip with vinyl bulb weather strip, with mounting screws. If the package has nails, buy screws to use instead. A package has three pieces to do one doorway.

Mount the Weather Strip

        1. Measure the sides and top of the doorway and cut pieces of weather strip. The left and right sides may be different.

        2. Use a hacksaw to cut the aluminum and a knife or scissors to cut the vinyl. If your door swings inward, stand outside and close the door. Push the door away from you to make the gap as large as possible.

        3. Mount a piece of weather strip to the latch side of the doorway. A door may move about 1/8” while latched, so the weather strip should be mounted to barely contact the door when the door is farthest from the weather strip, so that the bulb is compresses about 1/8” when the door is closest to the weather strip.

          Do not put the screws in tightly because the final turn can move the weather strip slightly. After each screw is put in, check that the door latches and there is no gap.

        4. If you have a lock with a vertical slide bolt, (interlocking door deadbolt), check if this still locks easily after putting in each screw. These are hard to adjust if they don’t lock easily. If the door will not latch and a screw must be moved, drill a new hole for it in the aluminum strip, using the 1/8” bit. If you don’t do this you will drive the screw into the wood next to the previous hole and it may move into it.

        5. After mounting the first piece of weather strip, check that a credit card cannot slide behind it when the door is pushed inward.

        6. Mount weather strip to the top and hinge sides of the doorway. In these locations the door is more “forgiving”, you probably don’t need to check if the door closes after putting in each screw. Check that the door latches and test the lock with vertical slide bolt if there is one.

        7. If the door has a deadbolt, check that it locks and unlocks easily. If not, file about 1/16” from the hole in the strike plate.


Type 4 – Spring Bronze Weather Strip

Spring bronze weather strip, or spring metal weather strip, is mounted to the door jamb to contact the top and side surfaces of the door. The other types of weather strip are mounted to a surface that the door presses against when closed. It normally lasts longer than the other types because it is nailed on and is made of bronze. Its disadvantages are that it is not perfectly air tight; the gap must be approximately 1/8″; and it cannot be mounted at the lock area unless you mount a “spring bronze lock strip”, which most stores don’t carry.

If the gap is less than 1/8″ the door can be planed. If the gap is wide, the weather strip can be bent to contact it, but it may not seal as well. Since spring bronze is not air tight, you could use it together with a self-adhesive weather strip mounted to the surfaces the door presses against when closed.

The tiny nails that are used can be driven in easily by using a small wooden tool called a “brad driver” or “brad pusher” with a hammer. These are available in some hardware stores and builders supplies.

      • If a door is warped enough that it doesn’t contact the self-adhesive weather strip at the bottom, spring bronze weather strip can be mounted to the bottom of the door jamb to seal the air at the bottom.
 

 

TOOLS AND MATERIALS:

        • Package of spring bronze weather strip. These have brass nails included
        • Brad driver
        • Hammer
        • Nail set or square cut nail (if no brad driver is used)
        • Metal shears
        • Sharp wood chisel to scrape the surface
        • Belt sander or plane

Mount the Weather Strip

STEPS:

        1. Check that the gap is about the same from top to bottom. If not, the hinge screws may be loose. Tighten any loose screws. If any cannot be tightened because the wood is slightly rotted, replace them with 2½” screws, which mounts the hinge to the wall stud. You may have to drive them in at a slight angle to enter a stud.

        2. Check that the gap between the door edge and the doorjamb is between 1/8” and ¼” all along the latch side and the top side. It may only need to be 1/16” wide on the hinge side because there the door forcefully compresses the weather strip. Where the gap is less than about 1/8”, belt sand or plane the door to create an 1/8” gap.

          If the temperature is very cold when you measure the gap and it is only about 1/8”, it will be less than 1/8” when it becomes warm and humid because the door will expand. The door will become very hard to close, so make the gap larger.

          To belt sand or plane it, remove the hinge pins, take off the door and set it up on its edge. If you sand or plane it while it is hanging, the new edge will probably not be straight.

        3. Scrape off any paint drops on the door’s edge to create a better seal.

        4. Using metal shears or large scissors, cut pieces of spring metal for the top and sides of the doorway. On the piece for the hinge side, you may need to cut a notch for each hinge.

        5. Using the nails in the package, nail on the left and right side pieces, but not the top piece. This is easier if you use a brad driver (brad pusher). Put in a nail on one end, and then stretch the piece and put in a nail on the other end to hold it in place as you nail it in.

          Drive the nails in just far enough to be flush, not enough to bend the spring metal. If the wood is slightly rotten at the bottom so the nail goes in too easily, use longer nails there.

        6. Carefully bend the weather strip out from the doorjamb enough to seal the gaps. Do not wrinkle it as you bend it.

        7. Before mounting the top piece, cut its ends at an angle that will fit against the side pieces when they are bent outward. Nail on the top piece. 

        8. Drive in twice as many nails as the instructions indicate because the doorjamb may have soft spots where nails have less strength.


Type 5 – Self-Adhesive Foam Weather Strip Tape

Self-adhesive foam weather strip tape has a rectangular contour and is available in many widths and thicknesses. It may be called, ”vinyl foam weather-seal self-stick tape”, “high-density rubber foam weather strip tape”, or “foam weather strip tape. “Low-density” tape has larger air pockets and is very compressible; “high-density” tape has very small air pockets, making it much more durable. The name may not tell if it is high density or low density, so you may have to squeeze it to check if it is compressible. If the width you need is not available, you can buy a wider size and cut it with scissors.

Mount the weather strip

      1. Buy at least two sizes and test each of them. The best thickness at the top may be different than at the bottom.

      2. Self adhesive weather strip will not stick well if the surface isn’t clean, so prepare the surface by sanding it or scraping off the paint with a wood chisel. Don’t wash the surface because it may not be dry enough for the tape to stick.

      3. Stick it on, then put in a staple or nail on each end because it comes off at the ends first.


Door Sweeps and Weatherizing Door Bottoms

Door sweeps and weatherizing door bottoms attach to the bottom of a door to seal the gap beneath them. Some are designed to also prevent rain from entering. 


Types of Door Sweeps

      • Conventional door sweeps have a rigid aluminum strip which holds a vinyl fin. The aluminum strip is screwed to the door, whether the door is wooden or metal. They are inexpensive, but they are not durable because the fin separates from the aluminum strip. 

      • There are two types of single-fin door sweeps that are designed to be more durable than conventional door sweeps. One has a thick vinyl fin that is clamped between an aluminum strip and the door by the mounting screws. These are available with an oak finish. Another type is similar to conventional door sweeps, but has a durable reinforced rubber fin, which is well-mounted to the fin.

      • Brush door sweeps have plastic bristles in place of a vinyl fin. They seal the gap when the threshold or other surface below the door is very irregular, and can be the best choice when there is no threshold.

      • Self-stick door sweeps have a vinyl fin that is held by a thin plastic strip that is stuck to the bottom of the door. These fall off before too long.

      • Flex-O-Matic door sweeps are designed to clear thick carpets. They have two aluminum strips that connect at a pivot joint, with a vinyl fin below them.  

 

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Choose and Mount a Door Sweep

      1. Check if the gap between the door and the carpet or floor becomes much smaller as you open the door, because the floor isn’t level. If so, mount a door sweep with the widest available fin, or a Flex-o-Matic door sweep.

      2. If your door is wider than 36”, very few stores offer door sweeps that will fit it. You may need to buy two door sweeps.

      3. If the threshold is not directly under the door, so a door sweep would not contact it, buy a multi-fin bottom sweep (not door sweep). Some of the fins should contact the threshold. These are described below.

      4. If there is no threshold, use a durable type of door sweep. The two described above are the “aluminum and reinforced rubber door sweep” and the “triple fin door sweep”.
      5. Cut the door sweep. Cut it to the width of the doorway, not to the width of the door. Your measurement may be slightly inaccurate, so it is safer to measure the width of the door and add to it estimates of the gaps on either side. Use a hacksaw to cut an aluminum or oak frame, and use scissors or a knife to cut a vinyl or rubber fin. If your doorway is wider than 36” and you will mount two door sweeps, cut each to half of the width of the doorway.
      1. To mount a door sweep onto a metal door, use the screws in the package. Drill holes in the door slightly smaller than the outer diameter of the screws, using a sharp drill bit. Self-tapping screws are stronger but unattractive.

      2. If the door is wooden and the bottom is slightly weak from rot, use 1″ or 1¼” screws to mount the door sweep. Also, drill extra holes in the door sweep and put in extra screws.


Types of Weatherizing Door Bottoms

      • Multi-fin door bottoms wrap under the door in either an L-shape or U-shape. They have from 4 to 6 vinyl fins that sweep against the threshold. They are more attractive than conventional door sweeps because they are not as visible, and seal the gap better than a single-fin door sweep, especially if the threshold is badly worn or not well-aligned with the door.

      • L-shaped multi-fin bottom door bottoms have an aluminum frame and a vinyl bulb with very small fins on the bulb. Some L-shaped models cannot be seen from inside the house. Most, if not all have replaceable vinyl inserts which you can buy at a hardware store.

        L-shaped models are relatively thick, so you may need to saw off about ¼” from the bottom of your door. U-shaped models have a vinyl frame that wraps around the bottom of the door, with the fins attached directly to it. They are thin so you won’t need to cut the door. They are more visible than L-shape models. See, “How to Choose and Mount a Multi-Fin Door Bottom”, below.

      • Pile weather strip can be mounted in a notch on the bottom surface of a door to seal the gap. It is not visible and it is very durable if glued on correctly. It can be used if the gap is very small, or if it is very small when the door is fully open because the floor is un-level. You can cut a notch for it using a router or a circular saw. See “How to Choose and Mount Pile Weather strip”, below.


How to Mount a Multi-Fin Door Bottom

      1. Measure the width of the doorway, not the width of the door. Cut the multi-fin door bottom to this length.

      2. Mount the door bottom. If the door is metal, use either the screws provided or use self-tapping screws, which are stronger. To use the screws provided, drill pilot holes slightly smaller than the outer diameter of the screws. If the door is wooden and the screws go in too easily, the wood is slightly rotted. Use 1″ or 1 1/4“ screws and put in about three extra screws.

      3. If the door is wider than 36”, mount two door bottoms. Door bottoms are normally sold only in lengths of 36″. Cut each to about half of the width of the door.  


How to Choose and Mount Pile Weather Strip

      1. Pile weather strip is available in several fiber lengths, but only the largest length, 1/2″ is suitable for doors. Window repair shops carry this length, but home centers and hardware stores normally only carry smaller sizes called, “Storm Door and Window Pile Weather Strip”. Buy at least 4 ft. because you may use several very short pieces to test different types of epoxy. 

      2. If you buy the weather strip at a window repair shop, ask them which epoxy to use. If you order the weather strip online, buy several brands of epoxy that bond vinyl or plastic, and test each of them by gluing a 1″ piece of the weather strip to wood. They should be tested because the weather strip has a polypropylene base and this is not listed on epoxy packages.

TOOLS AND MATERIALS:

        • Pile weather strip, 1/2″ fiber length
        • Circular saw or router
        • Wood chisel (any size)
        • Hammer
        • T-square or yard stick
        • Several brands of epoxy

Mount the weather strip

      1. Do not work on a very cold day because the door must be removed for hours while the epoxy dries.

      2. Remove the door by pulling the hinge pins. Set the door on sawhorses or a table. Use a T-square or yard stick to draw a line.

      3. Use a plunge router or a circular saw to cut a 1/16” deep groove in the surface of the door. If a circular saw is used, make two cuts and chisel out the wood between them. Scrape the groove to make a smooth surface for the epoxy to adhere to. 

      4. Glue in the pile and allow it to dry. Do not use wire nails or wire brads because temperature changes will cause them to slide out


Door Thresholds

All doorways should have thresholds because without a threshold, any type of weatherizing door bottom or door sweep will drag on the ground and wear out too soon.


Types of Non-Insulating Thresholds

      • Oak Saddle Thresholds – These are the conventional simple, wooden thresholds. They are called “saddle thresholds” because their bottom surfaces are shaped to contact the floor at either edge but not in the center, to prevent rocking. They are all similar in height, about 1 1/16”. This can be a problem; a thinner or thicker threshold may be needed. They are more easily discolored by dirt than aluminum thresholds, and they eventually wear down in small areas, allowing small gaps.

 

      • Aluminum Thresholds – These are more durable than oak saddle thresholds. The standard height is 1/2″ and is the only height available in most stores. 

      • Oak and Aluminum Adjustable Thresholds – These have screws which you turn to control the thresholds’ height. Most available models can be adjusted from 1 1/8” to 1 3/8”. If the distance between the floor and your door is between about 1½ ” and 1 3/4 “, you could use an adjustable threshold to create a gap of the right size for the type of insulated door bottom on your door. If the gap is greater on one side of the door, the threshold can be adjusted for this. They are less durable than most other types.

      • Interior Wood Thresholds – These are oak and approximately ½” thick. There are at least two widths available, 2 1/2 “ and 5”. They can be used in an exterior doorway if necessary.


Types of Insulating Thresholds

      • Insulating thresholds are designed to contact the door to seal the gap. Most have a compressible weather seal, called a “vinyl insert”. The vinyl inserts are not durable, but they are easy to replace and are sold at hardware stores and home centers. The types shown below are available in the weatherization section of home centers and in many hardware stores and builders supply stores.

      • Oak Insulating Thresholds – These are more attractive than aluminum insulating thresholds, but not as durable. They are only available in heights of approximately 1”. With the vinyl insert, a 1” high threshold is about 1¼”. Their inserts are less available than the vinyl inserts in aluminum thresholds.

 

      • Aluminum Insulating thresholds- These have a removable vinyl insert. They are available in a wide range of heights, from about 3/4“ high to about 1 1/8” high, plus the height of the vinyl insert.

      • Adjustable Height Aluminum Insulating Thresholds – These have a separate piece of aluminum that holds the vinyl insert, which can be moved to different heights. One popular model can be adjusted from 1 3/8″ to 1 5/8″, plus the thickness of the insert. They are not durable because the piece that holds the insert is supported by small, aluminum serrations (see picture). You can make one stronger by sliding in small blocks of wood before you mount it.

      • “Bumper Style” Insulating Thresholds – These have a vinyl weather seal that contacts the face of the door when it closes. They are unattractive, but may be suitable for basement and garage doorways where the appearance of a threshold is less important. They can be used when the gap under the door is too small for other types of insulating thresholds. If you have a metal basement or garage door with a small gap, a bumper style threshold may be your only choice because you cannot cut the door to make the gap larger.


How to Mount a Threshold to a Wooden Floor

TOOLS AND MATERIALS:

        • Threshold
        • Handsaw if oak threshold, hacksaw if aluminum threshold
        • Bevel
        • Tape measure
        • Drill
        • Crowbar or prybar
        • Hammer

Mount the threshold

      1. If the doorway does not have a threshold, measure the width of the gap under the door on both sides of the doorway.
            
      2. If the doorway has a threshold, remove it by unscrewing the screws or by prying it up with a prybar or crowbar. Measure the width of the gap under the door on both sides of the doorway.

      3. Buy a threshold. If you will use a door sweep, the gap above the threshold ideally will be 3/8”. If the gap will be much greater than this, a wide door sweep could be used.

      4. If you buy a threshold with a vinyl seal, check if the bottom surface of the door is smooth. If not smooth the vinyl will wear out too fast. To smoothen it, remove the door and sand the surface with a belt sander, or a palm sander with coarse sand paper. Paint it with primer and exterior paint to protect it from rot. 

      5. If there is not enough space for a threshold, remove the door and saw it to allow a larger gap. After making the cut, sand it with a belt sander, or a palm sander with coarse sandpaper. Allow for a 3/8′ gap, unless mounting a threshold with a vinyl seal. With these, the instructions tell what size gap the door should have. Paint the bottom surface with primer and exterior paint to protect it from rot.

      6. If replacing a threshold, use the old threshold as a template and mark the threshold to cut it. If the doorway did not have a threshold, check if the doorjambs are perpendicular to the threshold. If they are not, measure their angles with a bevel and trace them onto the threshold.

      7. Cut the threshold. Use a handsaw if it is oak or a hacksaw if it is aluminum.

      8. If the threshold is oak, mount it with 3” finish nails. Drill pilot holes through the threshold to prevent it from cracking, because oak cracks fairly easily. Do not drill the pilot holes close to the centerline of the threshold because the threshold could crack when hammering the nails.

      9. If the threshold is aluminum, drill pilot holes into the floor for the screws and screw down the threshold.

      10. If you are mounting an adjustable height aluminum threshold, set it in place with the door closed and adjust its height to the correct level, and then remove it. Cut several small blocks of wood to fit tightly into it, to prevent it from gradually falling.

      11. Apply clear exterior caulk around all sides of the threshold. This will prevent water from entering, freezing, and pushing up the threshold, and may prevent insects from entering.


Mount a Threshold to Concrete

A threshold can be mounted onto concrete in either of these ways:

      • Use a “powder actuated tool”. These use gun powder to shoot in special nails. They are available at home centers and builders supplies stores.
      • Use concrete screws. These are screwed directly into the concrete, into a pilot hole.  Most are blue, and called “Tapcon screws”. They are available at hardware stores and home centers.

      • Use screws with plastic anchors, and a hammer drill or compact hammer drill to make the holes.

 

TOOLS AND MATERIALS

Most of these depend on the method of mounting the threshold and the type of threshold)

        • Threshold
        • Handsaw if oak threshold, hacksaw if aluminum threshold
        • Bevel
        • Tape measure
        • Drill
        • Crowbar or prybar
        • Polyurethane construction adhesive
        • Clear exterior caulk
        • Wire brush
        • Small sledge hammer or framing hammer
        • Drill bits for wood
        • Package of 1/8” masonry bits
        • 1/4” concrete screws and 3/16” bits for concrete screws


For all methods of mounting a threshold onto concrete:

      1. If the doorway does not have a threshold, measure the width of the gap under the door on both sides of the doorway.

      2. If the doorway has a threshold, remove it by prying it up with a prybar or crowbar. Measure the width of the gap under the door on both sides of the doorway, it can be measured more accurately with the threshold removed.

      3. Buy a threshold. If you will use a door sweep, the gap above the threshold ideally will be 3/8”. If the gap will be much greater than this, a wide door sweep such as a “Flex-O-Matic door sweep”, which has two aluminum strips that connect at a pivot joint, with a vinyl fin below them; or an aluminum and reinforced rubber door sweep.

      4. If you buy a threshold with a vinyl seal, check if the bottom edge of the door is smooth. If not, remove the door and sand the bottom edge with a belt sander, or a palm sander with coarse sand paper. Paint it with primer and exterior paint to protect it from rot. 

      5. If there is not enough space for a threshold, remove the door and saw it to allow a larger gap. After making the cut, sand it with a belt sander, or a palm sander with coarse sandpaper. Allow for a 3/8′ gap, unless mounting a threshold with a vinyl seal. With these, the instructions tell what size gap the door should have. Paint the bottom surface with primer and exterior paint to protect it from rot.

      6. If replacing a threshold, use the old threshold as a template and mark the threshold to cut it. If the doorway did not have a threshold, check if the doorjambs are perpendicular to the threshold. If they are not, measure their angles with a bevel and trace them onto the threshold.

      7. Cut the threshold. Use a handsaw if it is oak, or a hacksaw if it is aluminum.


How to Mount a Threshold Using Masonry Screws

Masonry screws are driven directly into concrete, not into anchors. Pilot holes must be drilled, and pebbles in the concrete will prevent drilling in some spots. Hammer drills will drill through pebbles, but cannot be used to drill pilot holes for masonry screws because they make holes that are slightly too large. Thus, it is easier to mount a threshold onto concrete using a hammer drill, drilling holes for anchors for the screws to screw in to.

To mount a threshold with masonry screws, buy three flat head, ¼” masonry screws long enough to go through the threshold and enter the concrete by about 1”. Blue “Tapcon” masonry screws are normally used. Buy a package of four 3/16” masonry drill bits; one drill bit will not be enough if the floor is concrete because the pebbles in it damage the bits. 

        1. If the threshold is oak, drill three 3/16” holes through it (if it is aluminum it has holes). Do not drill the holes along the centerline of the threshold, drill them about ¾” from the centerline. The threshold is unsupported in the center and the force of the screws could crack it.

        2. Hold the threshold firmly in place and drill a 3/16” hole into the concrete at each hole in the threshold. Where the bit hits a pebble, drill at another spot. Dip the bit into water about every 30 seconds to prevent it from over heating and wearing out too soon.

        3. If the threshold is oak, drill out the top of each hole for the screws’ heads to fit into (countersink the holes)  

        4. If the threshold is oak, scrape the concrete surface with a wire brush and cover it with polyurethane construction adhesive. Lay the threshold and screw in the concrete screws.

        5. Caulk around all four sides of the threshold with clear, exterior caulk. This prevents water from entering, freezing, and pushing up the threshold, and may prevent insects from entering.

        6. If you mounted an insulating threshold that is slightly too high and the vinyl insert is forcefully compressed when you close the door, the vinyl insert will need to be replaced too often. Remove the door and remove 1/8” of wood from the bottom with a belt sander or plane.


How to Mount a Threshold Using a Powder Actuated Tool

Aluminum Threshold

        1. Shoot a nail into the concrete through each of the holes in the threshold. Use medium power level charges and nails just long enough to penetrate the concrete by ½” to ¾”. If a nail doesn’t enter far enough, hammer it with a small sledge hammer or large hammer such as a framing hammer.

        2. Caulk around all four sides of the threshold with clear, exterior caulk. This will prevent water from entering, freezing, and pushing up the threshold.

Oak Threshold

        1. Use a wire brush to clean the area where the threshold will be mounted. Apply polyurethane construction adhesive to the concrete. If the concrete is wet from rain or early morning dew, first dry it with a hair dryer.

        2. Drill two pilot holes for the nails at 1” from the center line. Drilling the holes here will prevent the nails from breaking the threshold. Using only two nails will reduce the risk of breaking the threshold, and the construction adhesive will give it extra strength.

        3. Shoot the nails into the concrete through the pilot holes. Use medium power level charges and nails just long enough to penetrate the concrete by ½” to ¾”. High power level charges could split a wooden threshold. If a nail doesn’t enter far enough, hammer it with a small sledge hammer or large hammer.

        4. Caulk around all four sides of the threshold with clear, exterior caulk. This will prevent water from entering, freezing, and pushing up the threshold.


How to Mount a Threshold Using Hammer Drill and Plastic Anchors

        1. Buy two 5/16” plastic wall anchors (normally the largest size sold), and two screws of the diameter used with these anchors, long enough to go through the threshold and through the anchors. Two are enough because the adhesive will provide extra strength.

        2. If the threshold is oak, drill two 1/8” holes through it for two screws.

        3. Using an 1/8” masonry bit, hold the threshold firmly in place and drill through the holes in the threshold and into the concrete. These will be pilot holes to guide the 5/16” masonry bit.

        4. Remove the threshold and drill into the 1/8” holes with a 5/16” masonry bit. A hammer drill will break through any small pebbles in the concrete. Hammer in the plastic anchors.

        5. If the threshold is oak, drill out the top of each hole for the screws’ heads to fit into to be flush with the threshold.

        6. If the threshold is oak, use a wire brush to clean the concrete, and apply polyurethane construction adhesive. If the concrete is wet from rain or early morning dew, dry it thoroughly with a hair dryer.

        7. Lay the threshold and screw in the screws.

        8. Caulk along the four sides of the threshold with clear, exterior caulk.


Insulate Doors By Repairing Doors and Door Frames


These types of damage can allow air leaks:

Repair the Door if the Corner is Rotted Away

If the rotted area is 1/2″ or less:

        1. Take down the door by removing the hinge pins.

        2. Remove the rotted area using a belt sander or wood shaver. Wood shavers cut wood cross grain better than do conventional planes.
        3. Glue on cedar shims to replace the rotted wood. Use construction adhesive because it is thick and joins surfaces that are not perfectly flat. Nail on the shims with tiny wire nails to hold them on tightly until the adhesive dries.


If the corner of the door is rotted away and the missing area is thicker than ½”:

        1. Saw off a triangular piece of the door at the bottom to remove the rotted area. Make the cut perfectly straight so the patch fits tightly. 

        2. If the wood is still slightly soft from rot after cutting off the rotted area, coat the bare surface with wood hardener to create a stronger surface to glue to. Wood hardener is sold in paint departments.

        3. Replace it with a triangular piece cut from a scrap door if one is available. Wood of the thickness of an exterior door (1 3/4”) is not sold. You could instead cut the piece from a 4”x4” post. If it is a basement door where it’s appearance is not very important, cut it from a 2×4 board. The patch will be 1/4″ thinner than the door. 

        4. Paint the surface of the door where you made the cut and paint the surfaces of the patch and allow the paint to dry fully before attaching the patch piece. The paint will prevent water from entering the pores and causing rot.

        5. Attach the patch piece.  Either  use wood screws or glue in dowel rods.  Using wood screws is not as good because they expand and contract, eventually causing a crack where the new piece meets the door and allowing water to enter.

          Whether wood screws or dowel rods are used, the patch piece should be bonded to the door with polyurethane construction adhesive because this is thick, so the surfaces don’t need to be perfectly flat. 

TO ATTACH THE PATCH WITH DOWEL RODS:

              1. Apply a heavy coat of polyurethane construction adhesive to one surface.
              2. Join the patch to the door temporarily with 2 thin screws to hold it while drilling the holes for the dowel rods and gluing them in. Drill pilot holes for the screws to prevent them from cracking the wood.
              3. Carefully drill three 1/2″ diameter pilot holes for 1/2″ dowel rods.
              4. Apply carpenters glue to the dowels and hammer them in.
              5. Allow it to dry, then remove the screws.
              6. Sand the repair with a belt sander as a finishing touch.

TO ATTACH THE PATCH WITH WOOD SCREWS:   

              1. Apply a heavy coat of polyurethane construction adhesive to one surface and hold the patch piece against the door.
              2. Drill one pilot hole through the patch and into the door. 
              3. Re-drill the pilot hole in the patch piece to make it as large as the screw. This will allow the screw to clamp the patch piece tightly against the door.
              4. Screw in a 2 1/2″ wood screw to attach the patch piece.
              5. Drill pilot holes for the other 2 screws and re-drill them in the patch piece to make them larger.
              6. Screw in the remaining two 2 1/2″ screws.
              7. Sand the repair with a belt sander as a finishing touch.


Insulate the Door if the Bottom Surface Is Badly Rotted:


There are several ways to seal the gap if the bottom surface of the door is badly rotted.

      • Mount a U-shaped insulating door bottom to cover the rotted area. 

        1. Use 1” or 1 ¼” screws, not the screws in the package, because the wood is too weak for these short screws.

        2. Drill several holes in the U-shaped door bottom to put in more screws than it was designed for.

      • Saw off the rotted area.

        1. Take down the door and use a yard stick, T-square or board to draw a line where you will cut.

        2. Carefully cut the door with a rotary saw. If an insulating threshold will be used, smooth the surface with a belt sander.

        3. If some rotted area remains, apply wood hardener before painting. Paint will not otherwise stick to a rotted surface.

        4. Paint the surface with high quality exterior paint.

        5. To close the gap, mount an aluminum L-shape door bottom or mount an insulating threshold.

      • Wrap sheet metal around the bottom 1″ of the door. Use aluminum flashing. This is relatively heavy and is often used outside the home. Mount it with 1″ self tapping screws. Shorter screws would not be strong enough in rotted wood.


How to Repair a Door Frame that Moves at the Bottom When You Close the Door


A wall’s framing is normally nailed to a concrete floor. If it moves when you close the door, the nails entering the concrete have probably rusted away. To repair it:

      • Remove a section of the interior wall to expose the board that rests on the concrete floor. This is normally a 2 x 4. Be careful not to cut through electric cables or low voltage wiring. If the wall is drywall, cut it with a utility knife because a wall board saw could cut a cable or wire.

      • If the wall is drywall and you carefully cut out a piece from the center of one wall stud to the center of the next, and about 24″ high, you can re-mount the piece you have removed.

      • Nail down the board on the floor using a small sledge hammer and 2 1/2″ masonry nails, or a powder actuated tool.

      • Repair the hole in the wall.


How to Insulate a Badly Warped Door

      • A badly warped door was probably designed for interior use, and you should replace it. This is probably not a project for a do-it-yourselfer who has never done it. Wood must be cut away for the hinges, the door must be cut to fit perfectly, and the lockset must be installed- skills that take practice.

If the door will not be replaced and its bottom corner can be bent back to fit into the door frame, you can straighten it with temporary measures.

      • Mount an 8″ barrel bolt onto the bottom corner of the door. When you close the door, bend the door flat and close the barrel bolt to keep it flat. 

      • In addition to using a barrel bolt, mount thick self adhesive rubber foam weather strip to the door frame.


Insulate a Basement Door With a Corner Chewed Off by Rats

If the corner of a door was chewed off by rats, it could be insulated by wrapping it in sheet metal. The appearance would not be good, but may be acceptable for a basement door. Aluminum sheet metal, called “flashing”, is sold in rolls at home centers and hardware stores.

        1. Fold a piece of flashing around the corner of the door.

        2. Attach it with 1” self-tapping screws or 1 ¼” drywall screws. Shorter screws may not hold because the wood may be weak from rot.

Ways to Repair Door Jambs and Casing (Molding) that are Badly Rotted at the Bottom

Either the casing around the doorway on the outside of the house and/or the door jamb may have absorbed enough rain to be badly rotted, letting air into the house.  The casing may be mounted to the outer wall and door jamb, or it may be mounted to only the doorjamb. 

 

 

A. If the door jamb and the casing around the doorway are badly rotted at the bottom, check if the area is under water in a hard rain. If it is, fix this problem so the wood will not continue to rot after it is repaired.

      • Check if the drain outside that doorway is draining too slowly. If it is, rent an electric drain snake and open it, or hire a plumber or drain opening service.

      • Check if the rain gutters and downspouts are working correctly. The gutters may be clean, but overflow because they sag in the middle. You can check the rain gutters and downspouts either by watching them when it rains hard or by using a garden hose on the roof.

      • Check if water runs through your yard toward that doorway during a hard rain. Correct this by adding soil to redirect the flow away from the door.


If the Doorjamb and the Casing (Molding) Around the Doorway are Badly Rotted at the Bottom, Check if the Area is Under Water in a Hard Rain.

If the bottom of a doorway is badly rotted, check if it is under water during hard rains. This can happen on basement doorways that are below ground level. Try to prevent this from happening so the wood does not rot after it is repaired.

      • Check if the drain outside that doorway is draining too slowly. If it is, rent an electric drain snake and open it, or hire a plumber or drain opening service.

      • Check if the rain gutters and downspouts are working correctly. The gutters may be clean, but overflow because they sag in the middle. You can check the rain gutters and downspouts either by watching them when it rains hard or by using a garden hose on the roof.

      • Check if water runs through your yard toward that doorway during a hard rain. Correct this by adding soil to redirect the flow away from the door.


If the Casing (Molding) on the Doorjamb is Badly Rotted at the Bottom, Replace the Rotted Area or the Entire Piece.

      • If the door is in a location where its appearance is not important, such as a rear basement door, you can fill a large empty space with expanding foam sealant. This is sprayed from a can. It is paintable but does not give rodent protection. The rot may not spread because it was caused by rain water “wicking up” into that section of the wood, and if the wood becomes dry, the rot will die.
      • The casing around the door jamb can almost always be matched with a piece sold at a home center. It is normally “brick molding”, which is designed for this purpose, but other types of molding are used. 

STEPS:  

        1. If the casing is on the outer surface of the house wall and only the rotted area will be replaced, saw it off and replace it. Use a combination square to draw a line where the cut will be made. The new piece should be at least 8″ long to be strongly mounted. 

        2. If it is a very thick brick wall and the casing is on the inner surface of the doorway and nailed to the door jamb, first, use a combination square to draw a cutting line. Drill very small holes across the line, about 1/4″ apart, then cut across the line using a hammer and chisel.

        3. If the casing is on the outer wall of the house it will normally be nailed to the door jamb and not to the wall of the house. Remove the section below the cut or the whole piece using a hammer, and a pry bar or a stiff putty knife.

        4. If rotted wood is exposed, scrape off the rot and apply wood hardener.

        5. Cut a piece of casing to nail on. Thoroughly paint both ends to prevent water from entering. Also, paint the surface that was cut. Use a paint that combines primer and top coat.

        6. Nail on the piece using finish nails.

        7. Thoroughly caulk all around it, applying a very thick bead of caulk where it rests on the ground.

        8. Paint the new piece of casing after the caulk dries.


Repair the Door Jamb and Casing at the Bottom of the Doorway with Wood Filler or Wood Epoxy.

This repair will need to be re-done periodically, so it is better to replace the casing if matching material is available.  

          • Either wood epoxy or wood filler (water putty) may be used; wood epoxy is more durable, but much more expensive and some products take days to dry before painting. Wood filler is basically more suitable for larger repairs.

          • Using a hammer and 1/2″ or 1/4″ chisel, chisel out the rotted wood.

          • Wood filler and wood epoxy must be applied to dry, solid surfaces, so scrape away as much rotted wood as possible. If any remains, treat it with “wood hardener” This penetrates into the wood and has resin which binds and reinforces decayed wood fibers. It is sold in paint departments.

          • Apply the wood epoxy or wood filler with a putty knife. Make it thicker than the original surface because it will shrink slightly when drying, and it can be sanded down.

          • When the wood filler or wood epoxy is dry, sand it down to the original surface.

          • Paint the repair with high quality primer and paint. The repair will last longer if painted with a paint that protects it from rain and high humidity. If the rotted wood is pressure treated pine it must be painted with solid stain.


How to Repair a Door Jamb Nailed Directly to a Masonry Wall.

On basement doorways of very old homes, the door frames may be 2″x 8″ or 2″x 10″ boards nailed directly to a wall of brick or block, with no wooden framing. They have no separate door jambs, they have instead a  1/2″ deep notch for the door.

MATERIALS:

        • 2″x 8″ or 2″x 10″ cedar board. Sold at builder supply stores.
        • Cedar shims
        • Exterior paint
        • 2 1/4″ x 3/16″ Masonry screws with drill bits or 2 1/2″ hard cut nails.
        • Clear paintable exterior caulk

STEPS:

        1. The boards forming the left and right sides of the door frame may be nailed to the wall with only about 4 very large nails. If you cut out a piece of the board to replace it, you must cut below the lowest nail because each nail is necessary to support the frame.

        2. Cut the frame above the rotted area. If repairing the hinge side of a door frame, do not cut above the lowest hinge because the hinge cannot be mounted onto the repair piece.

        3.  Cut a repair piece from a cedar board. Cut into it a 1/2″ deep notch.

        4. Paint the surface of the frame that was cut, and the repair piece using exterior paint combined with primer, such as “Paint + Primer in One”. Put a thick coat of paint on the ends to prevent water from entering.

        5. Clean the wall surface with a wire brush and apply a heavy coat of polyurethane construction adhesive. Apply enough to prevent water from entering, because it could freeze and push out the repair piece.  It is sold in paint departments and is applied with a caulking gun.

        6. Nail or screw on the repair piece. It is necessary to use shims for correct positioning.  To use nails, use a large hammer and hard cut nails. Hammer in the nails between the bricks.

          Be careful it doesn’t move slightly when nailing it, it must stay aligned perfectly with the doorjamb. To use screws, use 2 1/4″ x 3/16″ masonry screws, and screw them into bricks, not into the mortar between the bricks.

        7. Caulk around the edges of the piece of wood with clear, paintable exterior caulk. Apply a very heavy bead of caulk on the bottom edge.


Replace the Rotted Part of a Door Jamb With a Patch Piece.

STEPS: 

        1. Use a combination square to draw a line above the rotted area.

        2. Carefully cut through the line with a hand saw to make a notch.

        3. To make a smooth cut for a tightly fitting patch, cut through the line with an “oscillating multi tool”.

        4. If you don’t have an oscillating multi tool drill 1/8” holes across the line. Using a hammer and a stiff putty knife, punch through the areas between the holes and remove the lower section. File the surface flat.

        5. Check if the piece of wood removed is 3/4″ thick or 5/8″ thick.

        6. Buy wood for the patch piece. If it is 3/4″ thick, cedar is available and should be used because it is more rot resistant. If it is 5/8″ thick, only pine is available. You could buy cedar and sand it down to 5/8″ thick with a belt sander.

        7. Cut the patch piece.

        8. Paint the surface of the door jamb that was cut, and both ends of the patch piece. Paint them with a heavy coat of paint to prevent rot. Use an exterior paint that is combined with primer, such as “Paint + Primer in One”.

        9. Screw on the patch piece.

        10. Caulk around the edges of the patch piece, applying a very heavy bead of caulk on the bottom edge. Cover the screws with caulk.

        11. Paint when the caulk is dry.


So try to be handy and use How Insulate Doors and Repair Doorways to make your doorways air-tight and your heating bills lower!