The other day we went to look at a house and saw something I hadn't seen before:
The house is a log building from the 1800s that has been quite heavily renovated, presumably in the 1970s. When I felt under the panel, there was a thick (maybe 1.5 cm?) porous board there, between the logs and the panel. Although we're not planning to bid on this particular house, I became curious. Therefore, I wonder:
1. What is that strange board?
2. Why?
3. How smart is it to have such a board tightly against the logs?
It seems porous and should be able to absorb quite a bit of water if it comes into contact with it, and the moisture would then remain directly against the logs, sort of like a wet sponge...or? Perhaps it doesn't absorb as much as one might think? (There were some signs of rot damage on the sill in one corner, but that could also be because one of the cornerstones had shifted a bit).
The house is a log building from the 1800s that has been quite heavily renovated, presumably in the 1970s. When I felt under the panel, there was a thick (maybe 1.5 cm?) porous board there, between the logs and the panel. Although we're not planning to bid on this particular house, I became curious. Therefore, I wonder:
1. What is that strange board?
2. Why?
3. How smart is it to have such a board tightly against the logs?
It seems porous and should be able to absorb quite a bit of water if it comes into contact with it, and the moisture would then remain directly against the logs, sort of like a wet sponge...or? Perhaps it doesn't absorb as much as one might think? (There were some signs of rot damage on the sill in one corner, but that could also be because one of the cornerstones had shifted a bit).
Even asfaboard can probably feel porous, and it seems a bit more logical in that placement.
Presumably as a wind barrier inside the paneling. I believe it is water-repellent, so it shouldn't be much of a risk in that situation, as long as there is a gap between it and the paneling. But timber houses are a bit of a science of their own, so there's probably a lot that can go wrong there.
I would think it is a porous fiberboard. It was used a lot in the past on log houses as insulation. This board breathes and releases moisture pretty much the same way wood does. Those boards are held together by the wood's own lignin. Nowadays, they are usually impregnated with asphalt and are then called asfaboard. But there are also ones that only have a surface of tar and are then just made of wood fibers.