Roofing

GRP roof ponding and making crashing/popping noises

Anonymous user 09/03/2024 - 3.28 PM

We completed a ground floor extension 12 months ago, and the builder replaced the previous felt roof with a new GRP for both the old part of the roof plus the new extension. We've always had a problem with water ponding on the last metre of the roof, as a gradient hasn't been correctly considered. Our builder never seemed to agree this was an issue but we eventually convinced him to sort it out in January. He tried adding more GRP to create a slope, but this hasn't fixed it. The new covering has also cracked, and over the past couple of months we've started to hear loud popping/crashing sounds on a daily basis. He's said that the trim has lifted in the middle after the recent storm, and that's why his attempt at fixing it didn't work. We've had 1 specialist roofing company look at since, they said there's curling from the drip edge, lifting brickwork and insufficient sealant to lead flashings. Our builder wants to come back next week and fix the ponding problem, but we have no confidence in him.When we asked him about the noises he just said it was birds, or light winds Then said that as the roof structure consist of the following construction, it basically can't move, and it's impossible for the noises to be caused by any structural issues: On top of extension walls you have 8x2 C24 timbers, on top of the timbers you have furrings, on top of furrings you have 18mm structural ply, on top of the structural ply you have 120mm Celotex insulation, on top of the insulation you have 18mm OSB ply and on top of this you have the fibre glass. The fibre glass trim has been moved by the wind but this cannot move the structure underneath it as it is all bonded together. Just wondering if what he says is correct and if we should allow him another chance to try and fix?