Dormers need particular attention because they are exposed to the weather and have many junctions between materials that need checking regularly.
How dormer windows are built
Dormers may have flat or pitched roofs. If pitched, they are usually covered in slate as they are generally too small to suit larger concrete tiles.
The sides of the dormer (cheeks) may be covered in metal such as lead, copper or zinc. Slated cheeks need to be double or side nailed.
Ridges are built like those on pitch roofs. However, gutters (if provided) drain into a side flashing on the roof.
Dormers may have hips (‘piends’) where two sloping areas of slate meet. A ‘crown piece’ covers the join between several ridges.
Problems
Dormer windows may have been added later, removing rafters in the roof and weakening the structure. This can cause the roof surface and ridge to sag.
Dormer in need of repair. Slipped vertical slates, facings in need of repainting or replacement, lead soakers missing.
Window frames usually have timber facings covering the vertical joints. Paintwork is likely to require more frequent attention, as high level paintwork suffers particularly from exposure to the weather.
Ridges, hips, slate, gutters, flashings and windows may all need attention.
Insulating dormers
Dormer windows are very exposed and a lot of heat can be lost through them. Insulation needs to be added over the existing wall finishes.
Professional help recommended?
Although the work may appear straightforward, ensure your builder or tradespeople have the skills for the job. If in any doubt, get professional help to specify and organise the repair.
Who pays?
The issue about who pays for dormer repairs is not always straightforward.
