We are interested in a house that we inspected today. The house is old, built in 1914, but according to the inspector, it might be even older. The structure of the house is made of clay bricks. It is not a half-timbered house but instead just built up with clay brick. The current owner has completely renovated the house; basically, only the clay brick wall is original, meaning the structure. From the inside, the wall looks as follows, with my amateurish description 
, I hope you understand anyway... Gypsum => 50mm insulation => windproof paper => battened air gap (with 45x70) => clay brick wall => battened air gap (45x70) => windproof paper => 70mm polystyrene => Plaster
The inspector saw a significant risk in not having a vapor barrier (plastic) from the inside. That is, moisture can be transported, cooled, and condense against the clay brick, which can then be damaged.
I have googled a bit and read some. Many claim that you shouldn't have plastic on the inside and that clay brick has the property to absorb and transport moisture away. There is also the theory that clay brick needs a certain amount of moisture to avoid drying out, resulting in becoming too brittle.
The house has been in its current condition with added insulation since 1991, and nothing seems to indicate that it has "suffered damage." I guess that the insulation on the inside and the battened air gap is not only for insulation purposes but also to place all new electrical wiring in that layer and avoid having to chip out the walls.
Is there anyone knowledgeable here in the forum about old Skåne clay brick houses? What is the actual rule? Vapor barrier or not?
All information is greatly appreciated!
, I hope you understand anyway... Gypsum => 50mm insulation => windproof paper => battened air gap (with 45x70) => clay brick wall => battened air gap (45x70) => windproof paper => 70mm polystyrene => PlasterThe inspector saw a significant risk in not having a vapor barrier (plastic) from the inside. That is, moisture can be transported, cooled, and condense against the clay brick, which can then be damaged.
I have googled a bit and read some. Many claim that you shouldn't have plastic on the inside and that clay brick has the property to absorb and transport moisture away. There is also the theory that clay brick needs a certain amount of moisture to avoid drying out, resulting in becoming too brittle.
The house has been in its current condition with added insulation since 1991, and nothing seems to indicate that it has "suffered damage." I guess that the insulation on the inside and the battened air gap is not only for insulation purposes but also to place all new electrical wiring in that layer and avoid having to chip out the walls.
Is there anyone knowledgeable here in the forum about old Skåne clay brick houses? What is the actual rule? Vapor barrier or not?
All information is greatly appreciated!
Self-builder
· Stockholm
· 8 592 posts
What type of insulation is it?
I find it hard to believe that a clay brick wall would be damaged by moisture that condenses, but insulation/wood in the construction can.
However, if you have insulated with hygroscopic insulation, it transports moisture itself and overall, moisture should be able to be transported away to a sufficient extent to reduce the risk.
I find it hard to believe that a clay brick wall would be damaged by moisture that condenses, but insulation/wood in the construction can.
However, if you have insulated with hygroscopic insulation, it transports moisture itself and overall, moisture should be able to be transported away to a sufficient extent to reduce the risk.