How to Draught-Proof Your Home — Step-by-Step UK Guide

What You'll Need

Before You Start

• On a cold, windy day, walk around your home and feel for draughts. Run your hand around window frames, door edges, skirting boards, loft hatches and any other openings.
• A lit incense stick held near gaps will show air movement — the smoke is deflected by draughts.
• Do not block intentional ventilation — air bricks, trickle vents in windows, and extractor fans are there for a reason.
• If you have any open-flued gas appliances (e.g. an old gas fire), do not draught-proof that room without consulting a Gas Safe engineer. These appliances need airflow for safe combustion.
• Use our Draught Proofing Calculator to estimate material quantities and costs.

Step-by-Step Instructions

Doors

Step 1: Door Edges (Foam or Rubber Strip)

Clean the door frame rebate with white spirit to remove dust and grease. Measure the top and two sides of the frame. Cut self-adhesive rubber or foam strip to length and press firmly into the rebate where the door closes against the frame. Close the door to check the strip compresses evenly — it should seal the gap without preventing the door from closing.

Step 2: Door Bottom (Brush Strip)

Measure the width of the door. Cut a brush strip or door bottom seal to length using a hacksaw. Fit it to the inside face of the door at the bottom, so the bristles just touch the threshold or floor. Screw in place. The bristles should compress slightly when the door is closed but not drag when opened.

Step 3: Letterbox and Keyhole

Fit an internal letterbox draught excluder — a brush-type cover that mounts inside the door. For the keyhole, fit a pivoting cover disc over the key hole. Both are inexpensive and take minutes to install.

Windows

Step 4: Casement Windows (Foam Strip or Rubber Seal)

Clean the window frame where the opening casement meets the fixed frame. Apply self-adhesive foam or rubber strip (P-profile or E-profile for different gap sizes). Close the window to check the seal compresses evenly. Replace annually if using foam — rubber lasts longer.

Step 5: Sash Windows (Brush Pile Strip)

For sash windows, use brush pile strip fitted into a routed groove in the frame. This requires more skill — consider hiring a specialist sash window draught-proofing company. Alternatively, apply secondary glazing film or magnetic secondary glazing panels for the winter months.

Floors

Step 6: Suspended Timber Floors

Fill gaps between floorboards using flexible filler, papier-mâché strips, or proprietary floorboard gap fillers. Seal the gap between the skirting board and floor with decorator's caulk. Do not block air bricks under suspended floors — they prevent timber rot.

Other Areas

Step 7: Loft Hatch

Fit self-adhesive foam strip around the loft hatch frame. Fit catches or bolts to pull the hatch tight against the strip. If the hatch is warped, replace it with a new insulated loft hatch.

Step 8: Chimney

If you have an unused open fireplace, fit a chimney draught excluder (chimney balloon or sheep) to block the flue opening. Remove it before lighting a fire. For permanently disused chimneys, have the flue capped at roof level while maintaining a ventilation grille at the fireplace opening to prevent condensation.

Step 9: Pipework and Cable Penetrations

Seal gaps around pipes and cables where they pass through external walls using expanding foam or silicone sealant. Check behind radiators, under sinks and around boiler flues.

Common Mistakes to Avoid

• Blocking trickle vents: Trickle vents in windows provide controlled ventilation and prevent condensation. Leave them open.
• Sealing around gas appliances: Open-flued gas fires and boilers need airflow. Never draught-proof a room with an open-flued appliance without professional advice.
• Using cheap foam strip: Budget foam compresses permanently within months. Spend a little more on rubber (EPDM) or silicone strip for a lasting seal.
• Blocking sub-floor ventilation: Air bricks under suspended timber floors prevent rot. Never seal them.
• Forgetting the loft hatch: An un-sealed loft hatch is equivalent to leaving a window open. Always strip and seal it.

Cost Estimate (2026 UK Prices)

Use our Draught Proofing Calculator to estimate material quantities and costs for your home.