Why dormers need attention
A dormer is a small structure projecting from a sloping roof, with its own walls (cheeks), roof and window. It has many junctions with the main roof, and any one of these can leak. Over time, trapped water rots the timber frame, which is often relatively light, and the dormer can start to sag or twist.
Warning signs
- Damp or stained ceilings and walls in the loft room
- Sagging dormer roof or bowing cheeks
- Soft or spongy timber around the window frame
- Cracked or lifted lead, or failed flat roof covering
- Gaps between the dormer and the main roof
- Windows that stick or no longer close properly
How we assess and repair
We start by locating the source of water and checking how far decay has spread. Often the outer covering, such as lead or tiles, has to be stripped so the frame can be inspected. Rotten studs, rafters, plates and joists are cut out and replaced with treated timber, and structural connections to the main roof are rebuilt where needed. The cheeks are re-clad in a suitable material, and the roof is re-covered with proper falls and ventilation. Window frames are refitted or replaced, and flashings renewed, see lead flashing replacement.
Loft conversion dormers
Dormers built in loft conversions may not always have been constructed with enough structural support, especially where a rafter was cut. If you see sagging or cracking, we can check the structure and recommend strengthening, which might include new beams or ties. See also our roof timber strengthening and steel beam pages.
Local properties
Dormers are common on Victorian and Edwardian houses in Newcastle and North Tyneside, and on later homes converted to use the roof space. Coastal exposure brings stronger winds and driving rain that test every weak junction.
Regulations
Like-for-like repairs often do not need planning permission, but structural alterations might need Building Regulations approval, and conservation areas can limit changes to the roofscape. Check with the Planning Portal and GOV.UK.
Frequently asked questions
Can a rotten dormer be repaired or must it be rebuilt?
Depending on the extent of decay, repair is often possible. If most of the frame is affected, it can be more sensible to rebuild the dormer. We open up and assess before recommending.
Will repairing the dormer disturb my loft room?
Some internal disruption is likely if the frame has to be opened up. We protect the room and discuss the sequence of work with you beforehand.
