EcoRenovator - View Single Post - Affixing insulation board without thermal bridges?

Fionn · 10-24-16, 04:24 PM

You are risking serious health issues due to mould caused by interstitial condensation by putting so much insulation between you and the wall.
If you do a condensation risk analysis you will find that the dew point will be inside your house when you finish the work, this is not good.
The only way you can avoid this with this wall buildup is to put a vapour barrier between the insulation and the room, this would need to be taped to the floors, ceilings and around all window and door openings to avoid any possibility of moisture from the room getting in to the insulation.
Even doing this it may still happen. I think you should consult a building professional with experience in the area before you proceed.
As a general rule of thumb no more than 50mm of PUR is used for internal insulation for this reason - it moves the dew point into the wall.

10-24-16, 04:24 PM	#5
Fionn Lurking Renovator Join Date: Aug 2015 Location: Ireland Posts: 25 Thanks: 3 Thanked 6 Times in 2 Posts	You are risking serious health issues due to mould caused by interstitial condensation by putting so much insulation between you and the wall. If you do a condensation risk analysis you will find that the dew point will be inside your house when you finish the work, this is not good. The only way you can avoid this with this wall buildup is to put a vapour barrier between the insulation and the room, this would need to be taped to the floors, ceilings and around all window and door openings to avoid any possibility of moisture from the room getting in to the insulation. Even doing this it may still happen. I think you should consult a building professional with experience in the area before you proceed. As a general rule of thumb no more than 50mm of PUR is used for internal insulation for this reason - it moves the dew point into the wall.