Draughts around traditional sash windows are common, but uncontrolled air leakage is not the same as useful ventilation. Appropriate sealing can improve comfort without sacrificing the window’s operation.
Where draughts develop
Air can pass at meeting rails, staff beads, parting beads, the lower rail and gaps between the case and surrounding wall. Movement, paint build-up and worn components can all contribute.
How brush seals are used
Specialist draught-proofing systems typically use discreet brush seals fitted to accurately adjusted beads or rails. They must allow the sashes to move and should not obstruct drainage or essential ventilation.
Avoiding moisture problems
Older buildings need a considered approach to moisture and ventilation. Sealing windows without assessing indoor humidity, extract ventilation and condensation can create new problems.
What to combine with draught proofing
Repairing loose glazing, replacing failed putty and addressing rotten timber may be necessary first. Curtains, shutters and appropriately specified secondary glazing can provide additional comfort improvements.