So, if a slate roof needs a pitch of 33 degrees, a stone roof must have one of 45 degrees or more. The irregularities of the surface increase friction and the risk of leaks into a home at lower angles.

Flat roofs in contrast need a smoothness, slight tilt and large drains to reduce the risk

So, why this interest in roof design…do email if you think you know. More from us next time?

Tags: behaviour