Leaking corrugated garage roof

[Ben R]

Hi

We've just bought a house with a double garage with a shallow-sloping corrugated roof (part plastic coated steel sheeting, part what looks like fibre-glass sheeting). Water is dripping down the wooden beams of the garage from the rain and, I think, condensation. The leaks are caused by the bright spark who built it attaching the sheets to the timbers at the trough of each corrugation rather than at the crest/peak. Has anyone got any ideas on how I can solve this without having to buy new sheeting?

Thanks in advance

Ben

[Andrew Mawson]

shallow-sloping

Ben,

Strangely, putting the screws through the valleys of the profile is the recommended way, with each screw having a conformal washer to make the seal. I querried this with Southern Sheeting when I roofed an outbuilding but they were adament. Counter inuitive isn't it!

[Colin Wilson]

Take the sheets off and flip them over ?

[Steve Walker]

Loosen or remove each fixing, slather the hole with silicone or bitumenised roofing muck, stick a rubber washer over it and refix. That should get rid of most of the leakage, I reckon?

[Harry Bloomfield]

Ben R was thinking very hard :

Attaching the sheet steel down by the troughs (if you are referring to those) is absolutely the correct method. The bolts used should have an integral rubber like washer, which is designed to seal itself between the underside of the bolt and the sheet. Check the correct bolts have been used and that the rubber washers are intact. Bolting through the troughs is the only way to produce enough pressure to get a proper seal, otherwise the metal sheet would simply deform.

[Ben R]

Dear All

Thanks for your help - I stand corrected and should have never been so flippant with my bright spark comments.

The bright spark has used the screws with the rubberised washers but many of the screws and the metal part of the washers are quite corroded, so I guess that replacing them and using silicone sealant will be the best bet.

Cheers again

Ben