I am about to start decorating a room in the basement and need some help and advice on how to handle the walls.
In the sketch below, there are two walls that are exterior walls (those that are marked to be insulated). These walls are not insulated today. There is a Platon mat on the outside, but no insulation as mentioned. The wall at the top is an interior wall (concrete) against a finished and heated recreation room. The walls on the left are to be newly installed.
I need some advice on how to proceed. Should I build new walls all around to achieve a nice smooth interior wall (gypsum)?
Should I leave an air gap on all walls, even the interior wall against the recreation room?
Is an air gap needed at the top against the ceiling for air circulation?
The wall at the bottom of the image feels like something has been done to it, as it doesn't feel like solid concrete when you knock on it. Should I try to open a hole in the wall to see what they have done, or just build a new wall?
I would prefer to build inward into the room as little as possible, where it's not necessary.
I gratefully welcome all your thoughts, considerations, and tips.
You mean to insulate the exterior walls from the outside? The alternative, insulating from the inside, is a well-documented risk construction. This is true even if you have a platonmatta on the outside of the basement wall, I would say. On the other hand, you shouldn't always have to be so darn scared about basements and organic materials. There is often a hysteria around basements, but in some cases, organic materials work, and in considerably more cases, they don't. If you know your house reasonably well, I believe you can make a relatively good assessment on your own. Unless, of course, you're laying insulation and studs directly against the exterior wall.
Long explanation about organic materials, but if you absolutely want to insulate from the inside then... Otherwise, the absolute best is of course to just plaster the walls, paint with silicate paint, and then sleep peacefully at night.
The insulation is not the main issue. At least not for me. I just want to build the room properly so that you can live in it without the risk of various risks afterwards.
Then you can probably skip the insulation and go with plastered walls with silicate paint. Alternatively, you can set up walls with metal studs that are not in contact with the exterior wall (belt and braces). On this, you can then put drywall, and as you mentioned, leave an air gap at the bottom and top. I've considered this myself, but I think there could be a risk of a significant dust trap behind the drywall. No one has been able to answer my question regarding this.
