Draughtproofing Windows and Doors

If you have a UPVC door or windows, draughtproofing will almost always be included as part of the design. However, if you have wooden doors and window frames, they might not be as draughtproof as you would like. There are several simple and quick things you can do to improve the draughtproofing of your home.

Draughtproofing Doors

Doors have several areas prone to letting in draughts, so you might need to use one or more of these excluders to complete the job. If you are not sure where the draught is coming in, light a candle and slowly move it around in front of the door until you see it flicker.

Strip Excluders

Strip excluders are long thin strips of either foam, rubber or sometimes nylon brush which are stuck or pinned into the rebate to create a seal when the door closes against them. They are designed to be compressed, so don’t worry that they look thicker than the gap between the door and the rebate.

You can also buy strip excluders for the base of the door, on the inside. These are usually made from nylon or plastic bristles and good ones should be adjustable so that you can create a better seal.

Sill Seals

These are usually metal or rubber strips which sit on the sill (the floor beneath where the door sits when it is closed) and create a draughtproof seal when the door closes above them.

Two-piece Sill Seals

These work in a similar way to a normal Sill Seal except that a second piece called a deflector is attached to the bottom of the door which acts to direct rainwater out from the bottom of the door and away from the weatherbar (the bit screwed to the sill), which is stopping water and draughts being blown under the door.

Letterbox Excluders

As the name suggests, these are designed to stop draughts blowing in through the letterbox. They are usually made from metal or plastic and comprise a rectangular frame with two rows of nylon bristles running down each side and meeting in the middle. This is simply screwed into place over the inside of the letterbox.

Keyhole Covers

These small, round pivoted covers fit over your keyhole to stop draughts blowing through. On their own they are not going to do much to make your home better insulated, but as part of a complete door insulation project they should be considered. And they only cost about a quid…

Draughtproofing Windows

New UPVC windows should not be letting in any draughts, but older wooden windows (and sometimes metal windows) very likely will. Wooden sash and casement windows settle, warp and loosen over time and gaps will often appear around the frame.

Casement Windows

The easiest way to improve the draughtproofing of a casement window is to apply flexible rubber excluders between the frame and the moving part of the window. These excluders can be bought cheaply from most DIY stores and will usually have a strip of glue on the back to allow them to be fixed to the rebate.

Measure and cut a strip for each side of the window, as well as a strip for the top and the bottom. Peel off the backing paper of the first strip and carefully stick it to the rebate on the moving part of the window. Try to keep it straight as you do so. Repeat this for the three other sides of the window, trying to ensure that the excluder reaches right to each corner.

Sash Windows

Because the moving parts of a sash window slide, you cannot draughtproof them in the same way as with casement windows. The best method if probably to fit rigid brush strips on the inside of the frame as they allow the sash to slide easily past.

Measure the height of each separate sash and cut four lengths of the brush strip to size, two for each sash. With the window closed, fix the first strip to the left side of the frame so that the brush is against the inside face of the inner sash. Repeat this on the righthand side of the window before fixing strips to the outside of the outer sash in the same way. The strips should be pre-drilled and should come with pins for fixing. Foam strips can then be fitted to the top edge of the outside sash and the bottom edge of the inside sash to complete your draughtproofing.