Minimum pitch for low-pitch shed roof

PeteW

Hi,

I want to build a little office in my garden and under permitted development it can be up to 2.5m high.

I'm using this book as a guide, and want to build something similar to what is shown on the front, albeit a bit bigger.

My problem, is that the book suggests a roof pitch of 10°, which on a larger shed, gets quite low towards the back! In fact, once you've lost height to the base, floor, roof, joists, plasterboard etc I'd only be able to stand in the front half of the shed!

Any thoughts on if 10° is really necessary? I don't want a totally flat roof as I know it'll just leak. Something like 5° would make the space much more usable, but is that sufficient for rainwater clearance?

Thanks

Pete

EssexExile

A flat roof covered with rubber won't leak.

Whitterbod

https://www.bauder.co.uk/technical-centre/technical-literature/design-guides/flat-roof-design-considerations/falls-and-drainage ,
http://www.pavingexpert.com/gradient_01.htm
https://herbidacious.wordpress.com/2009/07/18/the-workshop-design/
A 1in 40 fall is 25mm per meter , the bauder link gives the fall as 1 in 40 and the paving expert has a gradient calculator hope this helps also percentage to gradient calculator , building a for meter wide workshop so my fall is 100 mm from side to side
Hopr yhe links help