The pitched roof of our house is supposed to be insulated as standard: construction (from outside to inside): tiles – protective membrane underneath – insulation – vapor barrier – small air gap – drywall.
Yesterday, during the autumn storm, I noticed that there is a draft coming through the wall/ceiling outlets for the lamps. Shouldn’t it be completely airtight to the outside because of the vapor barrier behind them?
Should I be concerned, and how high is the risk of mold developing in the insulation? If damage occurs, how would it be repaired? Would the entire drywall in the roof slope/ceiling need to be removed and the membrane resealed?
Thanks for the help.
Yesterday, during the autumn storm, I noticed that there is a draft coming through the wall/ceiling outlets for the lamps. Shouldn’t it be completely airtight to the outside because of the vapor barrier behind them?
Should I be concerned, and how high is the risk of mold developing in the insulation? If damage occurs, how would it be repaired? Would the entire drywall in the roof slope/ceiling need to be removed and the membrane resealed?
Thanks for the help.
dertill schrieb:
To rule out leaks in the airtight and vapor-retardant layer, the only method that comes to mind immediately is measuring the surface temperatures at the suspected spots. Maybe someone else has better ideas.If the draft were coming from the inside, I would actually prefer that. However, the fact that it is only noticeable during stronger wind conditions outside—and then feels distinctly cool, so rather below room temperature—argues against that...
Gunnar76 schrieb:
Cavity behind the drywallCould it possibly not be sealed toward the attic? The vapor barrier extended up to the collar beam level and then continued below the ceiling, and now cold air from the attic is blowing through the installation space?
Edit: Sketch added. Red = vapor barrier, green = ventilation gap
Thanks in advance... but I understand correctly: no matter where the connection between the indoor air and the space "behind the vapor barrier" is, mold is a risk? Or can one rely on the airflow behind it to dry it out over time?
(I’m a bit anxious about mold because in our last rental, the contractor forgot to install insulation in the upper flat roof – and during the first -20°C ( -4°F) winter, the edges underneath quickly turned black...)
(I’m a bit anxious about mold because in our last rental, the contractor forgot to install insulation in the upper flat roof – and during the first -20°C ( -4°F) winter, the edges underneath quickly turned black...)
I just realized that I wrote/drew something wrong. According to your description, the vapor retarder is on the insulation, not on the service layer (which would have been a strange setup). Sorry!
So it probably comes down to the issue described by @dertill. Something was done carelessly somewhere, and now the spot(s) need to be located afterwards.
In my opinion, a professional should handle this, as they also have the necessary equipment to carry out a minimally invasive inspection (e.g., an endoscope).
This does not necessarily have to lead to mold if left untreated, but it can.
So it probably comes down to the issue described by @dertill. Something was done carelessly somewhere, and now the spot(s) need to be located afterwards.
In my opinion, a professional should handle this, as they also have the necessary equipment to carry out a minimally invasive inspection (e.g., an endoscope).
This does not necessarily have to lead to mold if left untreated, but it can.
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