Fixing rattling, drafty aluminium windows

Most “the windows leak” complaints are a seal or an adjustment problem, not the window. Work through it in order before quoting a replacement.

1. Check the hardware first

On a casement, wind the friction stays and check the lock throws fully. A handle that only half-engages leaves the sash loose. On a slider, worn rollers let the sash sit low so the interlock no longer meets — replace the carriages. Tightening or replacing hardware fixes a surprising share of rattles at low cost.

2. Replace the weatherseals

Aluminium windows seal on a EPDM gasket in the sash or frame groove and on wool pile (brush) seals in sliding tracks. Both harden and shrink after a few years in the sun. Pull the old gasket, measure the groove width and the pile height, and re-run new seal from the roll. EPDM outlasts the soft PVC gasket that some windows ship with — switch to it on the rain-facing elevations.

3. Add compression where there is none

An old single-cam window that still leaks after new gaskets needs the sash pulled in at more points. Retrofit a multi-point lock or add extra cam keeps so the sash closes evenly.

4. Seal the frame-to-wall joint

If water is tracking in below the sill and not through the sash, the problem is the perimeter joint. Rake it out and re-seal with a low-modulus weatherproofing silicone over backer rod — not the same as re-glazing.

We stock EPDM gasket, wool pile, replacement rollers and cam keeps by the roll and the box. Bring a short offcut of the old seal and we will match the section.