Guide to Insulating Doors 

You can make any door air-tight by using a combination of weatherstripping along the edges of the door and a door sweep, weatherizing door bottom, or insulating threshold. You will often need to test different products to see which insulates best and you may need to buy one or two small 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 doorjambs or door stops on the sides and tops of the door frame may need to be repaired.

This web page shows you how to insulate many types of doors, and 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 repairing and weatherizing 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.

  • The most accurate way to check for leaks 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. 
  • Another way is to 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.
  • Another way is to 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.

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, hold the door tightly closed and check for leaks. 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. Hammer them in. This lets you move the screws slightly without going into to original holes. ssssssssssssssssssssssssssssss
  2. Drill pilot holes in the scrap wood and remount the strike plate. sssssssssssssssssssssssssss sssssssssssssssssssssssssssss
  3. If you must slam the door too hard either remount the latch again or buy an adjustable strike plate, which allows you to “fine tune” the adjustment. These are available at locksmith shops, home centers and hardware store. sssssss sssssssssssssssssssssssssssssssss
  4. 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.

Ways to Seal Air Leaks Around Weatherstripped Doors

  • If weatherstrip that fits in a slot in the doorjamb (kerf-fitted) is badly worn, replace it. Pull it out and insert a new weatherstrip. 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. 
  • Check that the storm doors close tightly against the weatherstrip in the frame.  If there are gaps which allow infiltration, 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 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 a storm door closes hard but does not latch, adjust the strike plate. 
  • 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 have 4 hinges.

Both types of hinges are screwed to a thin aluminum frame, and 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 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 normally, if not always 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 centers 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.
  • 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

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 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, 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 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 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 weatherstrip 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 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 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 weatherstrip, 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 to check if it is sealing tightly 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 with thicker material if there are gaps. Use self- adhesive “D-Shaped” EPDM rubber weatherstrip, 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. 

Scrape or sand the surfaces the tape will be stuck to for good adhesion. 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 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. 

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 wooden molding nailed to it, as a door stop for the other door. Weatherstripping will normally be attached to this molding. 

  • If air leaks through from between the doors, 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, seal the gap with  self-adhesive rubber foam weather strip tape. This may be called “foam weatherseal”. Only “low density” rubber foam weather strip tape (foam weatherseal) is very compressible.

    Prepare the surfaces it will stick to by sanding or scraping them. After sticking it on, staple on its ends with 3/8″ staples.

Some Ways 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 striker plate. Remove it, fill the holes with wood slivers, and drill pilot holes. Remount the weatherstripping.

How to Replace Broken Glass Panes in Doors

On exterior wooden doors, The panes in exterior wooden doors are held in place by strips of wood (beading) rather than glazing putty.


  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 brads. Flooring nails are square with flat heads. Tap in the nails carefully using a nail set, flooring nail or square masonry nail. If you have large slip-joint pliers, use these to squeeze the nails into the wood in place of nailing them. This will prevent breaking the glass.
  6. Caulk around the strips of wood. Paint the caulking after it dries.

How to Insulate Warped Doors

To weatherize a warped door with a large gap at the bottom corner 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 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 door stop molding that is nailed to the doorjamb, remove this molding on the latch side and replace it with weather strip door stop molding. This can be mounted in a slightly curved pattern to fit a warped door. These are wood door stops with vinyl weather strips inserted in them. 
  • If a warped door is in a doorway with a notched doorjamb rather than a door stop 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 weatherstrip. 


  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

To weatherize a sliding glass door:

  • 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 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 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 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 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 could also be used. It can be compressed to be paper-thin but it is not durable.

  • 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 a Door to Your Attic or 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.

  • If you don’t mount a threshold to the door to the attic, you could seal under under the door 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.
  • At the doorway to the basement, mount an attractive door sweep. 

Other Ways to Insulate a 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. 


  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.

You may also mount a ½” oak interior threshold and a multi-fin door bottom, which are also attractive. See, ” Door Thresholds“. 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 on the entry door 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, weatherproof it by replacing 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 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 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 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. There are more types of insulation than mentioned here, but these seem to be relatively durable.

Type 1 – EPDM Cellular Rubber Weatherstrip Tape

EPDM cellular rubber weatherstrip tape is self-adhesive tape made from EPDM cellular rubber. It may also be called “draft guard”. 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 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


  • Several sizes of 3/8” wide EPDM weatherstrip. 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 weatherstrip 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 Weatherstrip

1) .Do not mount the weatherstrip 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 weatherstrip 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 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 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 weatherstrip. 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 weatherstrip and ribbed profile weatherstrip is not available, which is thinner, cut D-profile weatherstrip to make it thinner. Using scissors, cut off the curved part to make it about 1/6” thick.

6) Stick the weatherstrip onto 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 weatherstrip with thinner weatherstrip. If a deadbolt or vertical slide bolt lock is hard to close a key could break.

7) Mount weatherstrip 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 weatherstrip with 5/16” staples, or nail in ¾” wire nails.

Type 2 – Weatherstrip Door Stop Molding

Weatherstrip 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. They have replaceable strips called a “door seals” which are available at come centers and hardware stores.  

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

How to Mount Weatherstrip Door Stop Molding

Weatherstrip door stop molding has a strip of weatherstrip inserted in a strip of wooden molding. It is unattractive when mounted onto a doorjamb, but not unattractive when used to replace a door stop. If a door is warped, you can seal the gap by mounting weatherstrip door stop molding to fit the curvature of the door.

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 weatherstrip 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 weatherstrip 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 weatherstrip more forcefully on these surfaces.

Type 3 – Aluminum Strip with Vinyl Bulb Weatherstrip

This type of weatherstrip has no standard name, its manufacturers have different names for it, such as “doorjamb weatherstrip”. It is made of a rigid strip of aluminum and a vinyl bulb.

The rigid strip is screwed to the door stop or to the doorjamb if there is no door stop, 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 weatherstrip.

How to Mount Aluminum Strip with Vinyl Bulb Weatherstrip


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

Mount the Weatherstrip:

1) Measure the sides and top of the doorway and cut pieces of weatherstrip. 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 weatherstrip to the latch side of the doorway. A door may move about 1/8” while latched, so the weatherstrip 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 weatherstrip.

Do not put the screws in tightly because the final turn can move the weatherstrip 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 weatherstrip, 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 Weatherstrip

Spring bronze weatherstrip, or spring metal weatherstrip, is mounted to the doorjamb to contact the top and side surfaces of the door. All other types of weatherstrip are mounted to a surface that the door presses against when closed. It can last for many years, much longer than other types, because it is nailed on and it is made of bronze. Its disadvantages are that it is not perfectly air tight, and 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″, plane or belt sand the door to make the gap wider. If the gap is too wide, the weatherstrip can be bent outward to fill the gap, but it may not seal as well. In this case you could use it together with a self-adhesive weatherstrip mounted to the surfaces the door presses against when closed. 

If a door is warped badly so that it doesn’t contact the self-adhesive weatherstrip at the bottom of the door, use spring bronze weatherstrip at the bottom of the doorjamb to seal the air.

The tiny brass nails, called “wire nails” that are normally in the package with the weatherstrip can be driven in easily with a small wooden tool called a “brad driver” or “brad pusher”. Use it to push in the nails. These are available in hardware stores and builders supplies.


  • 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
  • Wood Chisel (to scrape the surface)
  • Belt Sander or Plane


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 mount 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 door jamb 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) Use twice as many nails as the instructions indicate because the door jamb may have soft spots where nails have less strength.

Type 5 – Self-Adhesive Foam Weatherstrip Tape

Self-adhesive foam weatherstrip tape, also named “foam weatherseal”, 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.

It will close the gaps if they are too wide for other types of weather strip. 

“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.


  1. Buy at least two sizes and test each of them. The best thickness at the top may be different than at the bottom. ssssssssssssssssssssssssssssssssss ssssssssssssssssssssssss
  2. Self adhesive weatherstrip 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. sssssssssssssss ssssssssssssssssssssssssssssssssssss sssssssssssssss
  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.
  • 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.  
  • 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.

How to 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.

6) 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.

7)  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 seal the gap better than single-fin door sweeps, especially if the threshold is badly worn or not well-aligned with the door. If the threshold is too far forward, for example, a door sweep won’t make contact with it but at least one fin of a multi-fin door bottom will.

L-Shape models are more attractive than conventional door sweeps because they are not visible from inside the home. 

Aluminum multi-fin door bottoms have replaceable vinyl inserts.

An alternative to using a weatherized door bottom or a door sweep is to notch the bottom surface of the door and insert pile weather strip. It is not seen and it is very durable if glued on well.

It can be used if the gap is too small for a multi-fin door bottom. This occurs when the floor is not level and there is no threshold, causing the gap to be very small when the door is fully open. Pile weatherstrips are normally used in this circumstance, but they may last only a year. See, ” How to Choose and Mount Pile Weather strip“.

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. SSS SS ssssssssssssss sssss
  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. sss ss sss sss ss  ssssssssssssssssssss sss
  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 Weatherstrip

  1. Pile weatherstrip 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 Weatherstrip”. Buy at least 4 ft. because you may use several very short pieces to test different types of epoxy. sssss ssssssssss ssssssssss ssssssssss ssssssssss
  2. If you buy the weatherstrip at a window repair shop, ask them which epoxy to use. If you order the weatherstrip 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.


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


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 weatherstrip and allow it to dry. Do not use wire nails or wire brads because temperature changes will cause them to slide out

Door Thresholds

Types of Non-Insulating Thresholds

Oak Saddle Thresholds 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 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 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 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 door seals that 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 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 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 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). It can be made stronger by sliding in small blocks of wood before you mount it.

Bumper style insulating thresholds 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


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