Damp garage floor

Dustykitten

Our garage joins the kitchen via an internal door. We don't use it as a garage more as a store room, messy utility area. We have been trying to tidy it up so have painted the walls and mum gave us the old carpet from her bedroom to go on the floor. When we lifted the door mats/old carpet that was out there one corner is damp and the carpet a bit mouldy. The floor is now dry to the touch but if we cover it the damp comes back if that makes sense.

It is only in one corner (by the internal door). Any ideas what could cause this? It is a simple concrete floor. I do have a feeling that the waste pipes from the kitchen go under ground there so was worried that there could be a leak underground.

Wherryman

If it was originally a garage floor then it may not have a DPM (damp proof membrane) installed under the concrete so the damp may be coming directly from the ground underneath.

Dustykitten

Thanks for that. Is it possible to paint anything on to seal that corner or is that not a good idea?