I live in a townhouse built in 1971. Concrete slabs with a culvert underneath. Went down to look in the culvert and saw that there is a gap of about 5-10 cm between each concrete slab, meaning each household has its own slab. There is probably a good reason for this, including sound transmission between households.
We have ground radon in the row of houses, not particularly much, but enough that I want to do something about it. I suspect the gap between the concrete slabs is the main culprit for the radon.
Now to my question: can I, for example, fill the gap with foam to reduce the intake of radon? I'm wondering if there's any other architectural reason for the gap that I would disrupt by sealing it? Moisture?
Does anyone know?
My walls against the neighbors have double drywall insulation and an air gap. Wooden studs.
Best regards, Johan B
