Corrugated material for roofs? And a flashing question.

[JimD]

What is the most long-lasting corrugated materal for roofs?

The roof has a slight pitch (probably about 5 degrees). It is an extension on the back of a very old stone house. I'd also like to know the best sort of flashing to use, where the roof abuts the stone wall of the house. It needs to be something as well-sealed as possible to stop rainwater getting blown under it by the wind.

Thanks for any help.

JD

[Kevin Poole]

One of the modern fibre-cement sheets (e.g.

is long-lasting, but 5 degrees is too shallow for it.

I'd go for a steel profile. It's available either relatively cheaply and easily, in various profiles and either polyester or (longer-lasting) plasticote finishes, or, rather more expensively, as an insulated sandwich. All the accessories you might need, such as fixing screws, verge cappings, wall flashings, and profiles fillers, are available. At

5 degrees, you should also seal sheet side overlaps as per the makers' instructions.

As ever, the devil's in the detailing. Flashing anything to a stone wall could be tricky, depending on how flat the wall is. You'll almost certainly need to consider building regs, too.

is an informative site.

[Tim Lamb]

In message , Kevin Poole writes

You might also need to create a *drip* to encourage rain water to drop into the gutter rather than clinging to the underside of the roofing sheet.

I have sealed agricultural corrugated steel roofs with a 200 x200mm folded angle and then filled the gaps with expanding foam. Not at 5deg. and not involving BRs. however.

regards

[JimD]

Thanks, Tim (and Kevin). It would be feasable to increase the pitch of the roof - with some extra work. From what Kevin said, it sounds like it might be worth doing.

JD