I'm scraping off some plaster from a wall in the basement where I'm going to put tiles. I'm scraping where it feels like it might be a bit damp. However, I wonder about one thing. I started at the bottom of the wall and scraped. But a bit up, it seems like I've come to a seam. And in the seam, it feels like there's some paper or something. Looks black. So now I have to satisfy my curiosity and ask if it might be what's called Tjärpapp? And does it sit between all Construction Sections in the entire basement wall? Is the basement wall one big solid mass, or is it built in blocks? Sorry if I'm asking silly questions, but I'd like to know to increase my knowledge a bit. 
Thanks in advance!! Trying to attach a picture but unsure if it works since I'm writing from my mobile.
Thanks in advance!! Trying to attach a picture but unsure if it works since I'm writing from my mobile.I also have tjärrpapp under interior walls in my basement. It looked like they laid the paper on the floor and built the wall on top. The paper is supposed to prevent moisture from traveling from the floor up into the walls. If you found the paper higher up, perhaps someone has lowered the floor in your house to get higher up to the ceiling?
gaia
gaia
Okay, thanks for your response, now I understand how it works. The pappen starts about 2 decimeters up on the wall. It seems to be just that section up that is a bit too wet. I'm planning to repair it with concrete filler later.
The pappen starts about 2 decimeters up on the wall. It seems to be just that section up that is a bit too wet. I'm planning to repair it with concrete filler later.