GRP Roofing Problems Fixed (maybe)

[londonsteve]

Hi all,
Thanks so much for the advise on the first post, regarding the pinholes from the builders GRP installation

Leaks through our GRP flat roof

Hi we had a GRP flat roof put on our extension 1 year ago and have had a couple of leaks since, which the builders have come and used something to spot fill those holes. We're getting another leak now and when I go on the roof and have a closer look it looks like holes are forming around the...

www.diynot.com

They have come back sanded, and reapplied the resin and top coat. Most of the 1000's of pinholes have now gone, there's probably about 20 across the roof I've noticed. So there's that, but also that even when they left, the roof looks like its started lifting, as per the pictures. They've told us this is fine and that the roof is fully waterproof now, but I'm not so sure. Any advice on these pics would be great. Many Thanks.

Pin hole in the middle, but is that an issue?

 

[Rufus Raintight]

How did they repair? Did they sand the topcoat back to the first layer and then apply a new layer of topcoat, or just stick some more topcoat over the existing pinholes?

The Topcoat in these pictures look like it’s flaking, what evidence do you have that it’s lifted or de-laminated?

 

[londonsteve]

Hi, they sanded it back to the fibreglass so it was a whitey grey color before they reapplied the resin and topcoat. Sorry maybe flaking is the correct term then, I incorrectly called it lifting. We only see the flaking as in the pics above. Is that ok or an issue do you think?

 

[ree]

OP,
Before you cover a flat roof you must make sure that you have examined the joists, and properly prepped the bare deck.
Unless its been built & prepped correctly then all subsequent covers, of whatever materials, might possibly fail.
Failure will mean leaks - all flat roof leaks can be very expensive in their knock-on effects over time.

 

[londonsteve]

OP,
Before you cover a flat roof you must make sure that you have examined the joists, and properly prepped the bare deck.
Unless its been built & prepped correctly then all subsequent covers, of whatever materials, might possibly fail.
Failure will mean leaks - all flat roof leaks can be very expensive in their knock-on effects over time.

thanks the builders did all the joints and boarding, which I imagine is hard to check now? Assuming that is all ok though, would you say that top coat is an issue with the flaking? It looks like it’s all set now but they did it on a hot day so maybe it formed like that while they were doing it?

 

[catlad]

There will be a maximum temperature; ideally, not be done on a hot day.