We have a largish shed (garage sized) in our garden that used to be an old stable/coach house in Victorian times. It had a slate pitched roof but the last owner took it off and made it flat, single aspect, sloping into the garden.

This winter I noticed the ceiling was damp and occasionally leaked along the edges into the shed. A roofer came to have a look today and is pricing up a new cover. Interestingly he said the way the felt had been laid was wrong. The shed is rectangular and the current felt is laid with the long edge along the long edge of the building, like large tiles overlapping top to bottom.
The roofer said this was wrong and the proper way to do it is to have the felt run down the roof, top to bottom. This doesn’t seem right to me, but I’m not a roofer!

So, what’s the right way? Is there a correct way?

The roof felt needs to overlap. i.e the top edge is protected by the next roll of felt.

The laps will run parallel with the roof slope. i.e the long edge will run parallel with the roof slope. Work from the bottom up so that the next sheet overlaps and therefore protects the top edge from the previous sheet.

An EPDM membrane type roof would probably do it all in a single seamless sheet. I’m about to do my garage.
These guys are very helpful…

http://www.rubba-seal.co.uk/

We had our flat roof replace with a fibreglass cover – no leaks so far. We had to replace the rubber roof, which after 20 years plus, had started to perish around the edge. Our roofer had noticed a degree of bodyguard on the installation of the “rubber” roof

Sarna or similar ftw! However if its a shed roof you’ll probably want to stick with felt due to price difference….

http://singletrackworld.com/forum/topic/roofing-repairs-advice

Eskay beat me to it. I’ll be speaking with his supplier when were ready to roll 🙂