Velux Skylight Repair in Windsor & Berkshire

A roof window that drips is easy to blame on the window. Most of the time the window is fine. The leak is in the flashing kit around it, or in the tiles and felt next to it, and replacing the window keeps the leak.

The faults we find on Velux and other roof windows, in the order we find them:

• Flashing kit faults: a kit made for flat tiles forced onto a deep-profile tile, a kit that was never dressed down, or one that has lifted with age
• Felt cut short at the opening, so water that gets past the tiles runs straight in round the frame
• Tiles cut too tight or too loose to the frame, leaving water nowhere to run
• Perished seals and gaskets that let driving rain and draughts past the sash
• Misted glazing: condensation between the panes means the sealed unit has failed
• Cracked glass from impact or a falling branch

Water on the window board or down the reveal after rain, a stain on the ceiling beside the window, or a constant film of mist between the panes are the signs to look for.

A roof window is a hole cut in the part of your house whose whole job is keeping water out. It stays dry when the detailing around it is right, and it leaks every time the wind drives the rain sideways when it is not.

When we re-weather a roof window, we lift the tiles or slates around it and look at what is underneath. The felt is dressed into the opening and up the sides of the frame, so anything that gets past the tiles is carried back out over the flashing. The flashing kit is the one made for your covering, flat tile, profiled tile or slate, and fitted to the maker's instructions. The courses are cut and closed around the frame so water runs away either side rather than sitting against it.

Where the window sits in a flat roof, the problem is often the upstand it sits on. A frame bedded straight onto the covering sits in standing water. It needs a built upstand with the covering dressed up and over it.