As usual, when you try to do something small, it ends up involving a lot more
I've had problems with snails in the basement, and the final straw was when all my work clothes and shoes got completely slimed by snails.
I've found what seems to be the snails' eastern front (attached pictures), where they can freely crawl into the basement through the gap between the asphalt board and the foundation wall.
The joists in the picture belong to an extension, less than 10 years old. One half of the extension is on top of an old external basement staircase that has now become a basement. The photos are from this part. The other half is built on a post foundation with 20-100cm to the ground level. Two sides are walled, two are open.
The joists are against the wall, and then there are plywood pieces mounted from below to hold the asphalt board and insulation up.
My initial plan was just to pack the gap between the asphalt board and the foundation wall.
Should I have sill paper between the pack and the foundation wall in that case?
But then the asphalt board has sagged quite a bit, especially in the post foundation, so the insulation is sagging, and I assume the indoor climate is getting worse. It also smells a bit like cat pee in the post foundation. Whether it's from a cat or from the boards, I'm not sure (I read that they could start smelling if they get moldy).
In the part in the photos, I would like to have a proper ceiling, so I'm considering putting drywall there.
So, if you want to do this properly, how should you go about it?
In the post foundation, I thought about replacing the asphalt board with Byggmax subfloor panel that is placed between the floor joists.
Should I also replace the plywood strips with something else while I'm down there crawling around?
Should I do something else to prevent drafts? There's underfloor heating in the room above.
In the basement, I'm considering removing the asphalt board panels and putting plywood directly under the joists to support the insulation. Then drywall underneath that. Then there's the insulation against the wall... Should one put noggings between the joists to get a proper "sill" instead, and have a better chance of sealing it properly?
