Hello forum!
A few days ago, there was a leak from the ceiling on the upper floor - never a pleasant discovery!
So I took down the ceiling from the inside and located the problem. Some weatherproofing outside and the immediate danger was over... The leak turned out to have been there for a long time (completely black and rotten wood) and limited to about 1x0.5 meters. The persistent rain lately simply caused more moisture than usual to seep through, thus making it visible inside.
This is what the roof looks like (from the inside):
* Gypsum
* Vapor-tight plastic
* 200mm fiberglass insulation
* Masonite (4mm?)
* Battens and plank sheathing
* Tar paper
(* Possibly shingle - haven’t investigated yet because it’s a flat roof with a roof terrace above)
* 220 mm roof beams
But now I’m wondering a few things. I hope you know more than I do!
- The house was built in 1995 according to AB92 and ABT92 - does that tell what building techniques should be used, and where can I read more about it?
- It seems there is no air gap between insulation and plank sheathing, with the insulation against the sheathing. Is that okay? Today, I’ve heard that a waterproof yet breathable plastic sheet is placed on top of the insulation and a 20-30mm air gap above that. Wouldn't it be built that way according to AB92?
- The plastic sheet is not taped at the edges but overlaps. Is that okay? The good part here is that the leak was discovered early. The water didn’t accumulate for long above, but quickly seeped through and became visible. The bad part is that it’s not entirely tight - which should be the intention.
/Peter
