Roof windows have two separate seal systems — the weatherseal around the frame, and the sealed unit within the glazing itself. A failure in either causes different symptoms and needs a different fix.
Weatherseal vs Glazing Unit Failure
A failed weatherseal around the frame typically causes draughts or water ingress at the edges. A failed glazing unit shows up as misting or condensation trapped between the panes — a sign the gas fill or seal inside the double or triple glazing has broken down.
Signs to Look Out For
- Persistent misting between the panes that doesn't clear
- Draughts noticeable around the window frame edges
- Water tracking in around the frame during rain
- A visible gap or perishing in the weatherseal
How We Handle Seal and Glazing Replacement
- Confirm which seal has failed. Weatherseal or glazing unit — the fix is different for each.
- Source the correct replacement part. Matched to your specific window model.
- Fit the replacement properly. To the manufacturer's specification, not an improvised fix.
- Check for any related issues. Since a failed seal can sometimes indicate a wider problem worth catching now.
Noticed misting or draughts around a roof window? We can diagnose and fix it properly.
View Velux Windows →Why Choose Atlas Roofing Cheshire
We're a domestic and commercial roofing team covering Cheshire and the Wirral, based near Chester, so we know the area and can get to you quickly. Every job comes with clear pricing before work starts and workmanship you can rely on.