How to draught-proof doors

Video by Homebase. This guide draws on "How to save energy at home — Draught proofing doors" from the Homebase UK channel. It covers the main entry points for draughts around a front door and shows the materials used to seal each one. Practical and to the point — the bit on letterbox brushes is especially helpful.

1. Find where the draughts are coming from

On a cold, still day, hold your hand around the door frame and move slowly around the full perimeter. You can also use a lit incense stick — the smoke will drift toward any gap. The main culprits on most front doors are the letterbox, the keyhole, the gap under the bottom of the door, and the frame itself where the door sits in the rebate.

Older timber doors are often the worst offenders because the frame has dried and shrunk over years. uPVC doors draught less by design, but the seals degrade over time and can be replaced.

2. Fit a letterbox brush or flap

A standard letterbox is a significant hole in your front door. A draught-excluding letterbox brush — a frame with bristles that the postman's hand passes through but air cannot — fixes this properly. It screws into the same holes as the existing letterbox plate.

You can also fit a draught excluder on the inside: a hinged flap that falls back over the opening after the post drops. Either approach works; the combination of both works best. Measure your letterbox opening before you buy — sizes are not universal.

3. Cover the keyhole

A standard mortice keyhole lets a surprising amount of cold air through. A keyhole cover — a small rotating plate on a pivot that drops over the hole — costs very little and takes about two minutes to fit. They come in various finishes to match door furniture.

Night-latch locks and modern euro cylinders are better sealed by design, but an older-style keyhole is worth addressing if you have one.

4. Seal the sides and top of the door frame

Self-adhesive foam strips, compression seals, and brush strips all do a similar job here. Foam strips are the cheapest option but wear quickly. A compression seal — a rubber or plastic profile that compresses as the door closes — lasts much longer and gives a better draught seal.

Measure the full perimeter of the door opening, cut strips to length, and fit them to the inside of the stop bead (the raised bit the door closes against). Work around the full frame, checking that the door still closes firmly without forcing. Too thick a seal and the door will not latch properly.

5. Seal the bottom of the door

The gap under the bottom of a front door is often the biggest single draught point. A brush strip screwed to the bottom face of the door sweeps across the threshold as the door moves. An alternative is a hinged flap that lifts as the door opens and drops back under its own weight when it closes.

Measure carefully before cutting — the strip should run the full width of the door but not protrude over the edges. If the floor is uneven, a brush strip accommodates this better than a rigid seal.

6. Check the threshold seal too

On external doors, a threshold bar or water bar along the sill helps prevent cold air and rain tracking under. If the existing one is cracked, missing, or lifting at the edges, replacing it is straightforward — most are screwed down and the replacement drops straight in.

Once everything is fitted, close the door and check for obvious gaps with your hand. A well-draught-proofed front door makes a noticeable difference to a hallway on a cold Kent morning.

When to call a handyman

Call Richard if the door itself has warped or dropped and no longer sits evenly in the frame — draught strips will not fix a door that does not close properly. Also worth getting help if the threshold is damaged, if you want solid brush seals fitted all round rather than stick-on tape, or if the door needs adjusting before any draught-proofing will work.