Concrete Floor with Carpet over Damp around External Wall - Help Needed for Fix Help, advice, information, answers and tips on all types of flooring from laminate and carpet to timber and vinyl

[Junemoon]

My floor is concrete and carpeted with underlay since moved in 3 years ago. When I lift carpet the underlay is visably damp around the external wall roughly a 6 inch border if that makes sense. What is causing this? It's dry further in, the concrete itself is visably damp I.e darker color around the perimeter too. Please forgive me vaige post I've very little knowledge in this area. Thanking you very kindly.

[diydoctor6]

Hi Junemoon,
There could be many sources of your damp problem, but here is a good article to start your research:

https://www.diydoctor.org.uk/projects/dampcavity.htm

It seems likely that the damp is coming from the walls or edge of the concrete slab. You should look to see where the damp proof course is, assuming that it is there at all.

It might be useful to post some pictures both internally and also externally so people might be able to see the source of the moisture ingress.