A metal door draughts in winter even when properly closed
The Abimeister team · Updated · 5 min read
A metal entrance door that shut without a gap all summer and now lets in a cold thread of air along one edge is one of the most common winter calls we get. The lock still catches, the door still closes, but you can feel — or see a candle flame move — where the seal is no longer doing its job. This usually comes down to one of three things: the seal has hardened or shifted, the frame has moved slightly with the cold, or the strike plate no longer lines up the way it did in warmer weather. Here is how to work out which one you have.
Why the draught only shows up once winter arrives
Metal doors and frames expand and contract with temperature, and a Tallinn winter can take an exterior frame from well above freezing to well below it within a single day. Steel frames set into concrete or masonry openings move slightly as the metal contracts, and a gap that was invisible in July can open up to a couple of millimetres in January.
The rubber or foam seal around the door does the same thing in reverse: cold makes most seal materials stiffer and less able to flex into small gaps, so a seal that compressed nicely in summer can leave a thin channel for air once it hardens. Add wind pressure on an exterior wall and even a hairline gap becomes a noticeable draught.
This is normal seasonal behaviour, not a sign the door was fitted badly, though a door that was only just within tolerance in summer is the one most likely to show a problem once the cold sets in.
Where the air is actually coming in — check this before doing anything
Before adjusting or replacing anything, find the exact spot. Run a hand slowly around the full perimeter of the door on a windy day, or hold a lit candle or lighter near the frame and watch for the flame bending — a torch and a sheet of paper slid along the gap works almost as well if you notice the paper being tugged or lifting.
Note whether the draught runs along the whole hinge side, the whole lock side, just the bottom, or only one corner. A draught along an entire edge usually means the seal there has failed or the frame has shifted evenly. A draught concentrated in one corner, especially the top or bottom corner diagonally opposite the hinges, more often points to the frame itself being slightly out of square.
- Check the hinge side, the lock side, the top, and the threshold separately
- Note whether it is one corner, one full edge, or several spots
- Check whether the seal still springs back when you press it with a finger
- Look for daylight around the frame from outside at dusk
- Check if the draught is worse when wind hits that side of the building
What you can check and fix yourself before calling anyone
Start with the seal. Press it with a fingernail along its length — if it stays flattened instead of springing back, or if it has gone hard and shiny, it has lost its elasticity and needs replacing. Rubber seal strip for metal doors is sold by the metre and is usually straightforward to peel out of its groove and press a new length into, though matching the exact profile to your door model matters.
Next, check the strike plate and the latch. With the door open, see whether the latch or deadbolt lines up centrally with the strike plate opening, or whether it now catches high, low, or to one side. A small amount of misalignment can sometimes be corrected by loosening the strike plate screws and shifting the plate a couple of millimetres, then retightening.
If your door has adjustable hinges, most metal door hinges allow some in-and-out or side-to-side movement with a hex key, which pulls the door closer to the seal on the affected side. Try small adjustments — a quarter turn at a time — and test with the paper-slip method between each change rather than making one large adjustment.
When the problem is the frame itself, not just the seal
If the seal looks fine, the hinges are already adjusted as far as they go, and the draught is still concentrated in one corner or along one whole side, the frame itself has likely warped or shifted in its opening. This happens with age, with a building settling slightly, or when a frame was under stress from the start.
A frame that has twisted out of square cannot usually be fixed by adjusting the door within it — the metal fitting itself needs straightening, re-securing to the wall, or in some cases a section needs to be re-welded where a joint has opened up or a corner has flexed. This is where our metal fitting work, from 45 € an hour, or welding work, from 55 € an hour, comes in, depending on what the frame needs.
You can usually tell the difference from the outside: a seal problem feels like a thin, even gap you can close by pressing the door harder; a frame problem often means the door needs real force to latch on the affected side, or sits visibly proud of the frame at one corner even when locked.
What is a normal winter niggle and what needs attention now
A slightly stiff seal or a draught you can fix with hinge adjustment is a normal winter maintenance job, worth doing when you notice it but not urgent. The same goes for a strike plate that needs a two-millimetre shift.
It becomes worth acting on sooner if the door no longer closes fully flush, if you can see daylight through a gap that stays open even when the door is locked, or if condensation and frost are forming on the inside face of the door around the frame — that points to real heat loss and, over a winter, higher heating costs on top of the discomfort.
A frame that has visibly twisted, a corner joint that has separated, or a door that needs shoulder pressure to lock in cold weather are not do-it-yourself jobs and are worth getting looked at before the coldest part of winter rather than after.
A draught that appears only in winter is usually the seal or hinge alignment; a gap that stays open even when locked means the frame itself needs attention.