Leaking dormer flat roof rebuilt in EPDM — Brimington, Chesterfield

The customer in Brimington had already paid for several repairs to the flat roof on her dormer extension, and it was still letting water in. She came to us expecting to be told she needed a new roof.

Our survey found why the repairs had not held. The dormer roof had been built in two different coverings, felt on one part and rubber on the other, sitting at two different heights. The joint between them had never been finished off properly, so water was getting in there and around the chimney stack.

Why another repair was not the answer

The leaks were coming from how the roof had been put together, not from wear. Another patch over the joint would have been the same repair she had already bought. The lasting fix was to take out the weak points altogether: one roof, one covering, and no chimney standing in the middle of it.

What we did

• Took the chimney stack down to below roof height and packed the void with mineral wool insulation
• Built a new flat roof at the existing fall and carried it across to the party wall with the neighbouring roof
• Laid an EPDM rubber roofing system, in one continuous piece where possible, so there are no joints across the roof
• Finished and sealed the junction with the neighbour's roof, with new leadwork where it was needed
• Scaffolded the job for safe access and cleared all the waste from site