Sash Window Rattles and Draughts: What's Really Wrong

Diagnosing the common sash faults, and deciding honestly between repair and replacement.

Sash windows fail in predictable ways: the sash rattles in wind, drops when you open it, sticks in damp weather, or lets a draught through even when closed.

Each has a distinct cause, and most are repairable. This guide explains the diagnosis so you can judge whether a quote to replace the whole window is warranted.

The usual causes

Working from the most common down:

Repair or replace?

If the frames are sound and the problem is seals, balances or hardware, repair is straightforward and far cheaper than replacement.

If the timber is decayed at the sill or the frame has moved, replacement usually costs less than repeatedly repairing around a structural problem. On protected properties, repair may be the only permitted route regardless.

What to check before calling anyone

Note whether the draught is felt at the meeting rail, the sides or the sill; whether the sash stays where you put it; and whether the problem is worse in wet weather. Those three answers usually narrow the diagnosis before we arrive.

Get your sash windows assessed

We'll tell you plainly whether it's a repair or a replacement — and we're happy for it to be the cheaper answer.

Frequently asked questions

Can original sash windows be draught-proofed?

Yes — brush seal systems can be fitted to existing sashes and make a substantial difference without changing the appearance.

Will replacement sashes look the same?

Modern sash replicas can be specified with authentic sightlines, horns and glazing bars. On protected properties, check what your local authority accepts first.

Are sash windows always more expensive?

They cost more than a standard casement of the same size because of the mechanism and detailing. We'll quote both if you're open to either.

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