ᐅ Sandwich Roof and Insulation

Created on: 31 Aug 2021 13:10
N
Nico Haus
N
Nico Haus
31 Aug 2021 13:10
Hello everyone,

I have a house with a 4-degree (4°) mono-pitched roof made of 160mm (6.3 inches) sandwich panels. Since it gets quite loud when it rains, I am considering adding insulation underneath with mineral wool.

The beams supporting the sandwich panels are 200mm (7.9 inches) deep, so 200mm (7.9 inches) mineral wool would fit well, followed by OSB and drywall, or just drywall. Since the sandwich panels are not vapor permeable and already insulated, it seems a bit more complicated from my understanding.

Does the underside then need to remain vapor permeable? In other words, should there be no vapor barrier so that any moisture that may occur can escape downward? The house has a ventilation system, so indoor humidity shouldn’t be very high.

What would be the correct layer build-up in this case? Could someone help me with this?

Best regards and thanks in advance

Nico