ᐅ How can I prevent mold in the attic?

Created on: 2 May 2021 14:22
H
Heidi1965
The attic of our new build is accessed by a pull-down ladder. There are no windows there – neither in the gable nor any roof windows.

During the building drying phase (after plastering and after the screed), the hatch to the attic was completely closed. This was explained to us as a way to prevent mold growth. Since then, the pull-down ladder has been installed, and the attic has been lined with drywall panels. Now we notice a musty smell there, and mold spots are forming on the panels.

What can be done at this point? I have also asked the carpenter for advice at the same time.
Z
Zaba12
17 May 2021 20:13
T_im_Norden schrieb:

Was the drywall cladding planned from the start?

Normally, cold roofs are not covered. If they are, there are stricter requirements to prevent mold and avoid moisture buildup.
Exactly. You probably blocked the ventilation grilles, right?
H
Heidi1965
17 May 2021 20:40
Where are the ventilation grilles? It was the same company responsible for carpentry, roofing, and interior finishing. They should know what they are doing or should have warned us about the expected issue.
Z
Zaba12
17 May 2021 20:46
Heidi1965 schrieb:

Where are the ventilation grilles? The same company handled the carpentry, roofing, and interior work. They should know what they’re doing or at least have warned us about this expected issue.

Around there...

Close-up of a metal gutter at the roof edge above a wooden wall with autumn leaves in the background


It depends. I find it hard to imagine a roofer installing a cold roof lined on the inside with drywall without being prompted by the customer. It costs money and effort, so most likely they did exactly what you asked for.
H
Heidi1965
17 May 2021 21:06
I had assumed this was standard practice in new construction. We took our architect’s drawings to the contractors and hired them to build according to the plans. No one ever asked whether insulation boards should be installed or not. In the new buildings I have seen so far, all the attics were fully lined.
Z
Zaba12
17 May 2021 21:16
Heidi1965 schrieb:

Until now, I thought this was standard in new construction. We took our architect’s drawing to the contractors and commissioned them to build it. No one ever asked whether panels should be installed or not. In the new builds I’ve seen so far, the attics were all lined.

Those were probably not cold roofs and thus included in the building’s thermal envelope. Do you understand why the attic hatch is insulated and the cold roof must be ventilated? At least now you know what you’re dealing with. The problem will keep occurring without proper ventilation.
H
Heidi1965
18 May 2021 00:04
What exactly is the definition of a "cold roof"? The attic hatch is not insulated. It is a standard pull-down ladder starting from the upper "distribution corridor." The house has a second entrance door. Immediately beyond it is the staircase leading up to the 1 m² (11 sq ft) "distribution corridor." On one side is the door to the granny flat, and on the other side is the door to the "utility/party/multifunction room."