Draught Proofing Doors: Start at the Front Door
Draught proofing doors beats every other cheap comfort fix I know for a cold house, and you feel the draught first, long before you spot it. Try it on a windy evening: stand by the front door in socks, heating on, and a cold thread still finds your ankles. The room then feels colder than the thermostat says. Heating goes up, and you pay for warmth that slips straight outside.
Sealing those gaps costs very little, and one free afternoon with basic tools covers it. Windows and doors together often save around £40 to £60 a year in a typical gas-heated semi, though your home may differ. The Energy Saving Trust publishes fuller advice on draught proofing for the official figures. A DIY kit for the whole house often lands under £50, and a professional job usually runs £225 to £250, so check current quotes before you commit.
First, a distinction worth holding: draught proofing stops air sneaking through gaps. Insulation slows heat escaping through walls, roofs and floors. This guide starts at the door. Doors leak most, and one door teaches the whole job.
Which Door Deserves Your Saturday First
Front door first, back door second, internal doors last: external doors take the wind head-on and leak from four places at once. An internal door earns a seal only when it leads somewhere unheated, since sealing every one chokes the airflow a home needs to stay dry. I sealed a bedroom door once that led nowhere cold, and by morning the room felt stuffy.
Timber Doors Swell and Shrink
Timber shifts with the seasons: damp weather swells it, dry heated air shrinks it. A strip that fits in August can bind by January. Measure on a cold day when you get the chance.
uPVC Doors: Replace the Gasket, Don’t Strip Over It
Modern uPVC doors loosen with age. Suspect the hinges and locking points first, not the frame. Check those before you buy anything. A worn rubber gasket costs far less than a new door, and a strip over a failed gasket just hides the fault.
Composite and French Doors Need a Different Look
Composite doors tend to leak at the threshold, not the edges. Look down before you look around. French and patio doors leak most where the two doors meet, along the meeting stiles, and sliding doors add their tracks.
Find Every Leak Before You Spend a Penny
Spend nothing until you know where the leaks sit. A cold, windy day suits the survey best: draughts show up plain then.
- Hand test: move your palm slowly round frame, edges and corners, hunting for cool air.
- Paper test: shut a sheet of paper in the door and tug it. A sheet that slides free marks a weak seal.
- Light test: after dark, get someone to shine a torch from outside while you watch inside. Light showing through marks the gap.
- Smoke test: hold a lit incense stick near a gap you suspect and watch the smoke drift or flicker. Keep it well clear of curtains and fabrics.
Write each leak down as you find it, with masking tape beside it so you can find it again, strip in hand. That list is your shopping list.
Match the Strip to the Gap, Not the Packet
The whole job turns on one match: strip to gap width. Too thick and the door will not close properly. Too thin and the draught sits exactly where it was.
| Gap you find | Seal to fit |
| Paper grips lightly, draught faint | Thin foam or rubber edge strip |
| Paper slides free, gap you can see | Brush or wiper strip |
| Daylight showing at the bottom | Brush strip or hinged-flap seal |
| Bottom gap over a thick carpet | Hinged flap or drop-down seal |
| Bottom gap over a hard or uneven floor | Drop-down seal |
| Letterbox rattling or glowing | Letterbox brush or flap |
| Keyhole whistling | Swinging keyhole cover |
Torn between two thicknesses? Try the credit-card test: shut a card in the door on a test strip, where a card that needs forcing means too thick and one that falls loose means too thin. I keep a spare short length of each strip type in a drawer. Guessing from the packet has cost me a second trip to the shop before.
One external door usually needs edge strip for all four edges, cut from your own measurements with a little spare. Add one bottom seal, one letterbox brush or flap, and one keyhole cover. Buy for one door first. It teaches you which thickness your home actually needs.
Fit One Door in 7 Steps
Fitting order matters as much as strip choice. Start on the front door, then repeat the same order door by door.
1. Clean the Frame and Let It Dry
Wipe the frame clean and let it dry fully. Dust or damp stops adhesive strips gripping, and they peel off within weeks.
2. Measure Every Edge, Then Cut Long
Measure every edge you plan to seal. Cut each strip a touch longer than its gap, then trim the ends neat once fitted.
3. Press or Screw the Edge Strips
Self-adhesive strips go on a little at a time, fixed strips get screwed home. Either way, work along the frame: a full-length rush ends up crooked. Renters: self-adhesive strips, door snakes and window insulation film all peel off again. Ask your landlord first all the same.
4. Fit the Bottom Seal With the Door Closed
Fit the bottom seal with the door shut, marking screw positions before you drill anything. That puts the seal exactly where the gap sits. The door still has to swing free over your flooring. Test the swing before the last screw goes tight.
5. Fit the Letterbox Brush or Flap
Fit a brush or flap that closes properly over the letterbox. Post still has to pass through without catching, and a flap left hanging open keeps leaking.
6. Cover the Keyhole
Fit a small cover that swings over the keyhole. That tiny hole whistles louder than its size suggests on a windy night, and the cover finishes the door.
7. Close, Test, and Take a Second Pass
Shut the door and check the seal all round, then run the paper test again at every edge. Still leaking somewhere? A second pass on that one spot beats refitting the whole door.
Windows Leak Differently, So Seal Them Differently
Opening windows take strips between sash and frame. Fit them like door edges: clean, dry, measure, cut a touch long, peel, press firm, then shut and check the latch. Windows that never open take silicone instead.
Old timber sash windows want extra care: brush strips, parting beads and staff beads all play a part. Our dedicated guide to draught proofing sash windows goes deeper on those. Modern uPVC windows loosen too. Check hinges and locking points first, and swap worn rubber gaskets: far cheaper than new windows.
Seal the Gaps, Keep the Air, Avoid the Botches
Sealing is only half the job. A home still needs fresh air to stay dry and healthy. Cut that air off and moisture builds, then mould follows. Never block purpose-built ventilation: trickle vents, extractor fans, airbricks and wall vents stay open.
Kitchens and bathrooms need extra care: steam runs highest there. Gas fires, wood burners and open-flue boilers all need steady air to burn safely. Block that air and things get genuinely dangerous. Fit a working carbon monoxide alarm, and ask a registered engineer when unsure.
Again and again, the same five mistakes turn up, and every one could have been avoided. Check strips once a year before winter. Foam wears sooner; rubber and brush types last longer. Swap any strip sitting flattened, cracked or loose.
- Sealing trickle vents or extractor fans, trapping moisture inside and inviting mould.
- Fitting strips too thick, so doors and windows stop shutting properly.
- Sticking strips to dusty or damp frames, so the seals peel off in no time.
- Ignoring the rest of the house: floorboards, loft hatches and pipe gaps leak too.
- Skipping the survey, then sealing the wrong places first.
The Leaks Nobody Checks
Doors and windows are the obvious starts. Other gaps leak quietly all year round. Once the doors are done, give floorboards, skirting boards, loft hatches, unused chimneys and pipes a look.
A chimney balloon or a cap blocks an unused flue. Always take the balloon out before any fire is lit. Flexible filler closes floorboard gaps, and a foam strip round the loft hatch finishes that job. Our guide to energy efficiency solutions shows what comes next.
One Weekend, Four Chunks of Work
Saturday morning: an hour to find the draughts and measure the gaps. Saturday afternoon: another hour buying strips, seals and sealant from your list. Sunday morning is the bigger chunk, two to three hours fitting door strips and sealing windows. Sunday afternoon takes an hour for the letterbox, keyhole and loft hatch seals.
Test everything after: every door, every window. Each one should close and lock smoothly; note any spot that still leaks for a second pass. One weekend will not fix a rotten frame or a warped door. Stop there and call a professional: sealing a failing frame only hides the problem, and discreet sash seals from a specialist are worth paying for.
Free Help Exists for Some Households
Some households get draught proofing free or subsidised. Eligibility varies by benefits, property type and energy rating. Ask your energy supplier and your local council. Home Energy Scotland too, if you live there: schemes change often.
The Warm Homes Plan guide explains what support may be available. Worth checking before you buy anything. Check it before you buy anything, since a free survey sometimes comes with the scheme.
Questions Readers Keep Asking Me
Six answers come up more than any others, so settle these before you spend anything. Savings and ventilation first: those two questions decide whether the job is worth doing.
Worth the Effort, or Just Hype?
Yes, for most homes, since it costs little and rooms feel warmer straight away. Savings sit around £40 to £60 a year for a typical gas-heated semi, typical rather than promised.
What Will the Whole House Actually Cost?
DIY materials often come in under £50 for the whole house. A professional job usually runs £225 to £250. Region and openings move both figures.
Front Door: Which Excluder Actually Works?
Most front door draughts stop with four pieces working together: a rubber strip along the edges, a brush seal at the bottom, a letterbox flap and a keyhole cover. No single piece manages it alone.
Can You Seal Up and Still Breathe?
Yes, you seal round the frame and leave trickle vents, airbricks and extractor fans uncovered. Open windows briefly each day to clear moist air,
Will Sealing Everything Breed Damp?
It can, when planned ventilation gets blocked. Keep vents open and run extractor fans while cooking or showering. Steady airflow beats a sealed-up house for keeping moisture down.
Insulation or Draught Proofing: Same Thing?
No, draught proofing stops air through gaps while insulation cuts heat loss through walls, roofs and floors. Gaps first: cheaper to fix, and felt the same evening.
Pick a Weekend Before the Cold Sets In
Sealing your doors is cheap, quick and genuinely effective. Start with a simple survey and the biggest gaps first. Windows follow after. Vents stay open, and the home stays warm and dry.
Pick one weekend before the cold sets in and get started. For more jobs like this one, browse our DIY guides on this site.
