Flat roofing in Mere Green
Extension roofs, mostly. And the joint where your extension meets the house, which is where the water is actually coming in.
Almost all the flat roofing we do in Mere Green is on extensions, because this area has more of them per street than anywhere else we work. Single-storey rears, side returns, garden rooms, and the flat or near-flat roofs that go on top of them. When one of those leaks, people assume the covering has failed. Usually it has not.
The leak is at the abutment — the line where the flat roof meets the wall of the original house. That junction has to be a proper upstand with a stepped or straight flashing chased into a mortar joint and wedged. On a lot of Mere Green extensions, particularly the ones done quickly by a general builder rather than a roofer, it is a strip of self-adhesive flashing tape stuck onto the surface of the brick. That tape has a bond that fails as the wall cycles wet and dry through a few winters, and then it lifts at the top edge and channels water straight into the joint. We take it off and do it in lead.
The other thing we check before quoting anything is the fall. An extension roof that ponds has either sagged or was never laid to a proper fall, and putting a new covering over a roof that cannot drain just resets a short clock. We build the fall back with firrings first. For the covering itself, an extension roof with upstands, corners and a pipe or two through it is a fibreglass job — it cures in one piece, so there are no joints at the fiddly bits for water to find.
What people in Mere Green ask us.
The two we get most on this job round here. The full list is on our FAQ page, and the flat roofing page goes into the trade in more depth.
My extension leaks where it meets the house. Is the roof shot?
Probably not. That junction is the most common leak on a Mere Green extension and it is usually flashing tape doing a job that needs lead. The covering is often perfectly fine.
There is a puddle on my extension roof after rain. Is that a problem?
Yes. It means there is no meaningful fall left. Recovering over it buys a few dry years. We build the fall back with firrings before anything goes on top.