Topics

Three Ways to Detect Small Air Leaks Around Doors
Ways to Seal Air Leaks Around Doors and Attic Hatchways
Five Types of Weatherstrip 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. The tests below will then show very small leaks.

      • To air flowing into or out of your house, from inside your house, move an incense stick along the door’s side, top and bottom edges. If the smoke does not rise straight up, there is a leak. A candle is less effective.
insulating a door
Non-Contact Thermometer
      • Tape a thin plastic sheet over the door. It will billow inward if air is leaking into the house, or cling to the door if air is leaking out.
      • Use a non-contact thermometer. This allows you to 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. They are sold at home centers. 


Ways to Seal Air Leaks Around Doors and Attic Hatchways
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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 that 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.

Seal Air Leaks Caused by Loose Door Latches

      • If air leaks through at the sides or top of a door, pull the door in 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.
        3. 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.
        4. If you have a deadbolt lock, check if it still closes easily. If not, file the hole in the deadbolt’s strike plate to make it larger.
        5. If you have a lock with vertical slidebolt, you may be able to adjust it by remounting the piece that is mounted to the door frame.

 

      • If the latch strike plate is loose, try using larger screws. If the doorjamb is cracked where the screws enter, put in 2“ screws that will enter the frame behind the doorjamb.


If Weather Stripping Allows Air Leaks

      • If vinyl or rubber weatherstrip has been painted, replace it. It may have lost its flexibility.
      • If spring metal (spring bronze) weatherstrip is wrinkled, replace it. If it is tight but has large paint drops, scrape them off. Stretch it tightly as you mount it. You could instead leave it on and mount weatherstrip to the surface the door strikes (the doorstop).
      • If aluminum strip with vinyl bulb weatherstrip 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 weatherstrip will move back into its original position.
Cut-away view of kerf-fitted insulation in door jamb
      • If weatherstrip 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 weatherstrip 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.

Vinyl-Clad Magnetic Kerf-Ftted Weatherstrip for Steel Door

Vinyl-Clad Foam Compression
  Kerf-Fitted Weatherstrip




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. You first mount a metal frame to your doorway.

    • If you have a storm door with a door closer, check that it latches when the door closer pulls it shut. Test 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 and the threaded areas are slightly damaged. Replace some or all of the screws with slightly thicker screws. You may be able to use a few long screws and screw them into the wood

    • If you have a storm door, check that it contacts the weatherstrip when it is closed. If there are gaps, the storm door’s frame may not have been mounted to the doorjamb correctly. Insert shims between the storm door’s frame and the doorjamb where necessary. If this creates gaps between the frame and the doorjamb, caulk the gaps.

    • If a storm door contacts the weatherstrip 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 you have a storm door that closes hard but does not latch, adjust the strike plate. If it still won’t latch, file out the hole in the strike plate to make it larger.

    • 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 too unattractive for your front door. Replacement fins can be ordered.

Pile weatherstrip

    • Modern storm doors have thin brush-like strips called “pile weatherstrip” 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 weatherstrip”.

    • 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.


Insulate Attic Hatches

Attic hatch with pull-down stairs
Attic hatch with pull-down stairs

    • 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, the 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 weatherstrip to the wood the door rests on. See EDPM Cellular Rubber Weatherstrip 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, weatherstrip it with rubber foam weatherstrip tape. This compresses more than other weatherstrip materials. It is available in thicknesses of up to 7/16”. Only “low density” rubber foam weatherstrip 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 you don’t, buy a 16” wide roll of multi-purpose fiberglass insulation, for about $7. 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 weatherstrip. 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 weatherstrip because this is not durable.

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

If gaps are too wide for the weatherstrip, glue 1/2“ wide strips of wood to the surfaces of the door that the weatherstrip 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 weatherstrip tape. This compresses more than other weatherstrip materials. It is available in thicknesses of up to 7/16”. Only “low density” rubber foam weatherstrip 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 weatherstrip, check if it is sealing tightly. You can’t see the weatherstrip when the hatch is closed, so it is hard to check for a gap. One way is to paint the frame where the weatherstrip will contact it, and then close and open the door. Where ever the weatherstrip 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 weatherstrip in many locations around the frame. Where ever you can slide out the paper without effort there is a gap.

Replace the weatherstrip if there are gaps. Use EDPM cellular rubber weatherstrip tape. Carefully prepare the surfaces it will stick to by scraping or sanding them. After mounting the weatherstrip, staple down its ends with 5/16” or ¼” staples. If gaps are too wide for this weatherstrip, glue 1/2 “wide strips of wood to the surfaces of the door that the weatherstrip 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.


Insulate Double Doors

Exterior double doors are normally glass doors that enter onto a second floor porch deck or balcony. To be air-tight, one door must be 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 attached.

    • 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 slidebolts 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 slidebolt hole has been re-drilled to allow for it, mount thick, very compressible weatherstrip, which will seal a large gap. Only self-adhesive low-density rubber foam weatherstrip is thick and very compressible. Remove the weatherstrip and scrape the surface well to prepare it for self adhesive weatherstrip. Mount thicker weatherstrip where the door is warped, and thin weatherstrip along the rest of the surface. The thinnest available is ¼”, and will compress to about 1/16”.


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 for the strike plate. Remount the weather stripping.


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 rather than glazing putty. If it is held in by strips of wood:

        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. 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 brad. Flooring nails are square with flat heads. Tap in the nails carefully. If possible, instead of nailing them in, push them in by squeezing them into the wood with large slip-joint pliers.
        6.  Caulk around the strips of wood. Paint the caulk after it dries.


Insulate Warped Doors

1″ wooden doorstop with vinyl fin

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

      • If it 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.

      • Mount a weatherstrip doorstop to the doorjamb. This can be mounted in a slightly curved pattern to fit a warped door. If the doorway has a doorstop, remove it and replace it with the weatherstrip doorstop. If the doorway does not have a doorstop, mounting a weatherstrip doorstop to the doorjamb is too unattractive for a front doorway.

      • Mount bronze spring metal to the bottom of the doorjamb. This is the only durable type of weatherstrip designed to contact the surface edge of a door. If the door becomes more warped, the spring metal will still seal the gap.

Bottom of doorjamb with weatherstrip attached to a shim

      • Remove the weatherstrip, glue a thin piece of wood to the surface the weatherstrip was attached to, and replace the weatherstrip. To cut the piece of wood, buy a package of 1”x 12” shims. Cut a shim to ½ “ wide using a utility knife. Scrape off the paint and glue on the piece of wood. Nail it with 1” wire brads or 1” wire nails. Replace the weatherstrip.

1"x12" shim
1″x12″ shim

Cutting a shim
Cutting a shim












Insulate Sliding Patio Doors

      • Seal the gap under sliding patio doors. One way is to lay a small carpet next to the doors 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 polyeester 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 weatherstrip. Modern patio doors have either pile or thin vinyl strip weatherstrip 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 weatherstrip manufacturer or from the patio door manufacturer. Vinyl weatherstrip 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 weatherstrip, mount weatherstrip around them. Mount thin weatherstrip to the doorjambs to compress very flat when the doors are closed so the latch closes easily.

EPDM ribbed profile weatherstrip-1/8" thick
EPDM ribbed profile weatherstrip-1/8″ thick

Aluminum strip with vinyl bulb weatherstrip
Aluminum strip with vinyl bulb weatherstrip

EPDM ribbed-profile weatherstrip could be used; it is durable, but may be too thick. It compresses to about 1/16” thick. Low-density ¼” thick rubber foam weatherstrip tape can be compressed to be paper-thin. See Rubber Foam Weatherstrip 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 weatherstrip 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 Weatherstrip 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 you have sliding patio doors that will not be used all winter, “Shrink film” may also be used to insulate them. This is very transparent plastic film which you tape to the wooden frame around the doorway. It is effective because it is airtight and it creates a dead air space that insulates well, but you cannot open the patio doors. You tape it on with double-sided tape then heat it with a hair dryer to make it tight and transparent. It may be called, “Patio Door Insulation Kit”. It can only be used several times, so it may not lower your heating costs by as much as it costs, but it will make the room warmer while letting in light.

      • If your air conditioning costs are high, you could cover your patio door glass with insulating window film. It 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 if it is described by phrases such as, “blocks up to 99% of UV rays to help reduce fading”, but 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.


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.

Multi-fin door bottom
Multi-fin door bottom

      • Mount a ½” thick oak interior threshold at the attic doorway. Do not mount a threshold at the doorway to the basement because a person could trip on it and fall down the stairs. This insulation should be attractive, so use white EDPM cellular rubber weatherstrip tape. See EDPM cellular rubber weatherstrip tape. Mount a multi-fin door bottom at each door if the gap is not too wide or narrow, because these are more attractive than door sweeps. If one cannot be mounted, mount a white 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

Insulating door bottom with replaceable weather seal
Insulating door bottom with replaceable weather seal

Kerf-fitted multi-fin door bottom weather seal
Kerf-fitted multi-fin door bottom weather seal

Wooden threshold with vinyl weatherseal

      • Seal gaps under doors that have door sweeps, weatherizing door bottoms, or insulating thresholds, but still leaking air by replacing their replaceable parts or by making adjustments.

      • If your furnace or boiler is in a room with an exterior door and there is a louvered air vent on the wall that is sealed, the furnace is probably being supplied with air leaking in under the exterior door. Do not weatherstrip the exterior door unless you also open the air vent on the wall.

      • 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.

      • Insulate the door between your house and the garage. Garage doors are normally very drafty, and may be left open occasionally. Mount weather strip to the sides and top, and mount a door sweep, weatherizing door bottom, or insulating threshold at the bottom.

      • 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 EDPM cellular rubber weatherstrip 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.


Reciprocating saw
    Reciprocating saw

      • 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”.

Air-tight pet door
Air-tight pet door

      • If you have a pet door that was not designed to be airtight, replace it with an airtight 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” .

Jalousy door
Aluminum jalousie door

        • Seal the gaps between the glass slats on jalousie doors. In regions of the country where these doors are common, 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.

        • 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.

Backset Lock and Door Reinforcer
Backset Lock and Door Reinforcer

      • 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 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.

Wood panel door with floating panels
Wood panel door with floating panels

      • 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 Weatherstrip for Doors and How to Mount Them

It normally takes  trial-and-error to find the best weatherstrip for a door, in fact, the weatherstrip 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 Weatherstrip Tape

D-profile EPDM weatherstrip, 1/4" thick
D-profile EPDM weatherstrip, 1/4″ thick

EPDM cellular rubber weatherstrip 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 weatherstrip 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.

EDPM Ribbed Weatherstrip – 1/8″ thick

Medium size EPDM weatherstrip 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 Weatherstrip Tape to a Doorjamb

Tools and Materials

        • 3/8” wide EPDM weatherstrip of the sizes that will fit the gaps. Trial-and-error is usually
          necessary, so buy at least two sizes.
        • Sharp wood chisel or sandpaper
        • Hair dryer (only if air temperature is below 50° or if there is morning dew)
        • Shims and construction adhesive (only if the weatherstrip will be mounted to shims where the gap is wide)
        • Utility knife
        • Staple gun and 5/16” staples, or ¾” wire nails


Mount the Weatherstrip

        • Do not mount the weatherstrip if the outdoor temperature is below 40º or it has rained recently, as the instructions indicate.
        • On the latch side and at the top of the doorway, the weatherstrip should be mounted to the surfaces that 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.
        • Sand the surfaces the weatherstrip 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 them off with a wood chisel.
        • If the outdoor air temperature is below 50° , dry the frame with a hair dryer. The door frame will be very slightly damp from warm, inside air leaking out around the door and condensing on a cooler door frame.
        • 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 weatherstrip. Use a shim from a package of shims and cut a strip 3/8 “ wide with a utility knife. Scrape the paint off of the frame 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.
        • If the gap is too narrow somewhere for D-profile weatherstrip and if ribbed profile weatherstrip, which is thinner, is not available, cut D-profile weatherstrip to make it thinner. Using scissors, cut off the curved part to make it about 1/6” thick.
        • Check that the door latches easily and that the deadbolt or vertical slide bolt lock closes easily. If not, replace the weatherstrip with thinner weatherstrip. If a deadbolt or vertical slide bolt lock is hard to close a key could break.
        • Mount weatherstrip along the top hinge side of the doorway and check that the latch and lock close easily.
        •  If the door has a deadbolt lock and it is a little bit harder to lock, remove the strike plate and file the hole to make it larger.
        • Staple the ends of each piece of weatherstrip with 5/16” staples, or nail in ¾” wire nails.

D-profile EPDM weatherstrip mounted to doorway
D-profile EPDM weatherstrip mounted to door stop

D-profile EPDM weatherstrip
D-profile EPDM weatherstrip

D-profile weatherstrip with            
 curved part cut off
D-profile weatherstrip with curved part cut off

Bottom of doorjamb with shim
Bottom of doorjamb with weatherstrip attached to shim

Type 2 – Weatherstrip Doorstops

2"
2″ wooden doorstop with vinyl fin

1" wooden doorstop with vinyl fin
1″ wooden doorstop with vinyl fin

Weatherstrip doorstops have a strip of weatherstrip inserted in a strip of wooden molding.  They are not attractive when mounted onto a doorjamb, but are attractive when used to replace a doorstop, but most exterior doorways do not have a doorstop. If a door is warped, you can seal the gap by mounting a weatherstrip doorstop to fit the curvature of the door.


How to Mount Weatherstrip Doorstops

1" wooden doorstop with vinyl fin
Weatherstrip doorstop with compression weatherstrip

Dead bolt strike plate
Dead bolt strike plate

 

A. If the door jamb 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 it is, fix this problem so the wood will not continue to rot after it is repaired.

        1. 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.
        2. 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.
        3. 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.

B. If the molding on the door jamb is badly rotted at the bottom, replace the rotted area or the entire piece.

Brick molding
        1. 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.
        2. 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.
        3. 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.

C. 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. You shoot this in 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 nor”brick molding”, which is designed for this purpose, but other types of molding are used.

        1. If it is on the outer surface of the house wall and only the rotted area will be replaced, you can saw it off and replace it. Use a combination square and draw a line where the cut will be made. The new piece should be at least 8″ long to be nailed on strongly. Cut the casing carefully using a hand saw.
        2. If it is a very thick brick wall and it is on the inner surface of the doorway and nailed to the door jamb, remove it by drilling very small holes across a cutting line. Cut through the cutting line using a hammer and chisel.

          PRYBAR

        3. If the casing is on the outer wall of the house (not on the inner surface of the doorway), it is nailed only to the door jamb, 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 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 where it rests on the ground.
        8. Paint the new piece of casing after the caulk dries.

D. Repair the door jamb and casing at the bottom of the doorway with wood filler or wood epoxy. This repair will probably need to be re-done periodically, such as every few years, so if possible, replace the casing and repair the door jamb.

        1. Choose the best product. The label must indicate that it is suitable for outdoor repairs. 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.
        2. Using a hammer and 1/2″ or 1/4″ chisel, chisel out the rotted wood
        3. 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.
        4. 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.
        5. When the wood filler or wood epoxy is dry, sand it down to the original surface.
        6. Paint the repair with high quality primer and paint. The repair will last longer if painted with a high-quality paint that protects it from rain and high humidity. If the rotted wood is pressure treated pine it must be painted with solid stain.

E. Repair a door jamb that is 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 brick or block wall. 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 board that is one side of the 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 the cedar board. Cut a 1/2″ deep notch in it.
          4. Paint the surface of the frame that was cut, and the piece of cedar 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 and apply a heavy coat of polyurethane construction adhesive. This will seal the space behind the wood to prevent water from entering and freezing, and add strength to the repair. 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 that 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.

F. Replace the rotted part of a door jamb by replacing it with a patch piece.

          1. Draw a line above the rotted area and drill 1/8” holes across it. Using a hammer, and a chisel or stiff putty knife, punch through the areas between the holes and remove the lower section.
          2. Check if the piece of wood removed is 3/4″ thick or 5/8″ thick.
          3. 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.
          4. Cut the patch piece.
          5. 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”.
          6. Screw on the patch piece.
          7. Caulk around the edges of the patch piece, applying a very heavy bead of caulk on the bottom edge. Cover the screws with caulk.
          8. 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!