Weatherstripping a door means fitting flexible seals that close the gaps between the door and its frame, plus a separate seal for the gap at the bottom. Find where air gets in, choose a strip that suits the size of each gap, clean the surface, cut the strip to length and press or fix it in place so the door still closes and latches easily. Then deal with the bottom edge using a sweep or threshold seal.
Find the leaks first
Draughts (drafts, in American spelling) are easiest to find on a cold, windy day. Close the door and try these checks:
- The tissue test. Hold a strip of tissue or a light ribbon along the edges of the door. Where it flutters, air is moving.
- The back-of-hand test. Moisten the back of your hand slightly and run it around the frame; leaks feel noticeably cold.
- The light test. After dark, switch on a light on one side and look for a glow around the edges from the other side.
- The paper test. Close the door on a sheet of paper. If it slides out with no resistance, the seal at that point is not touching.
Mark each leak with a small piece of masking tape. Note how wide the gaps are, because that decides which product works.
Types of door weatherstripping
| Type | Where it goes | Good for | Watch out for |
|---|---|---|---|
| Self-adhesive foam tape | Inside the frame stop | Small, even gaps; quick fixes | Compresses and wears faster than rubber |
| Rubber or silicone bulb (tubular) strip | Frame stop, sometimes in a groove | Uneven gaps; long life | Needs the right profile size to let the door latch |
| V-strip or tension seal | Along the side jambs | Tight, discreet seal on well-fitted doors | Can be fiddly to fit neatly |
| Brush strip | Frame edges or door bottom | Sliding and uneven surfaces | Lets some air through by design |
| Door sweep | Bottom of the door face | Gap above a hard floor or sill | Can drag on thick rugs |
| Threshold or door-bottom seal | Sill or underside of door | External doors with a worn sill | May require trimming the door |
| Letterbox brush and keyhole cover | Letter plate and lock | Small but steady leaks | Check the letterbox still works for post |
How to weatherstrip a door frame, step by step
- Gather tools: tape measure, scissors or a utility knife, a mitre box or fine saw for rigid strips, a screwdriver or small hammer, a cloth and some mild cleaner.
- Remove old seals. Peel or unscrew worn strips and scrape off leftover adhesive.
- Clean and dry the surface. Adhesive strips fail fast on dust, grease or damp wood. Fitting on a mild day helps the glue grip.
- Measure each side separately. Do the head (top) first, then the two sides. Door frames are rarely perfectly square.
- Cut to length. Leave rigid strips a fraction long and trim after a dry fit. Cut rubber profiles cleanly so corners meet without a gap.
- Fit the strip to the frame stop, the part of the frame the door closes against. Press adhesive strips firmly along their full length; fix rigid strips with the supplied pins or screws.
- Test the door. It should close and latch with light pressure. If it springs back, the strip is too thick or set too far forward.
- Check corners and the latch side, where gaps often survive the first attempt.
How to stop a draft under a door
The bottom gap is often the largest single leak. Options, from simplest to most permanent:
- Fabric draught excluder: a weighted fabric tube laid along the bottom. No tools, easy to move, but needs repositioning every time.
- Stick-on or screw-on door sweep: a rubber or brush blade fixed to the inside face of the door so it just touches the floor when closed.
- Door-bottom seal: a U-shaped rubber channel that slides over the bottom edge of the door.
- Threshold seal: a raised strip on the floor or sill that the door closes onto. Useful when an external sill is worn.
Mistakes that undo the work
- Choosing a strip so thick that the door no longer latches, which strains hinges and locks.
- Sticking tape onto a dusty or painted-yesterday surface.
- Leaving the head of the frame unsealed, where warm air escapes most readily.
- Sealing the room so well that moisture has nowhere to go.
Keep ventilation where it belongs
Draught-proofing targets accidental gaps, not purpose-built vents. Never block air bricks, trickle vents, extractor fans or the vents that supply air to open fires, wood burners or fuel-burning boilers, because those appliances need air to burn safely. Fit a carbon monoxide alarm in any room with a fuel-burning appliance. Rooms that are well sealed but poorly ventilated can also suffer from wet windows; the guide on stopping condensation on windows explains how to strike the balance.
Where this fits in a wider plan
Doors are usually one of the cheapest leaks to fix, which is why they sit near the top of most action lists after a home energy audit. Cutting draughts also lowers the heat a house needs, which matters if you are weighing up new equipment such as a heat pump or furnace. Replace worn seals whenever the paper test starts slipping again; foam tapes in particular tend to need more frequent renewal than rubber profiles.
Desk habits
Small routines that save time later
Picked up while writing the notes on this site.
Photograph the meter
A dated photo settles most arguments about estimated readings.
Name files by date
Year, month, day at the start of a filename keeps invoices and letters in order.
Sketch before you measure
A rough floor plan stops you missing an alcove or counting a strip twice.
Update the router
Check for firmware updates whenever you change your Wi-Fi password.
Put terms in writing
A short email confirming price and due date beats any verbal promise.
