Damp Advice (concrete floor)

8 Mar 2014
Reaction score
United Kingdom
Hi Forum,

My lounge floor has a serious damp problem which has been diagnosed as the concrete slab. As you see from the photo the damp permeates the immediate area, has affected the plaster on the chimney (plaster in contact with floor) as well as adjacent alcove walls.


Two questions:

1) I have noticed more sweating on the floor on hot days like today (damp clearly glistening) compared to rainy days where it becomes dry. Is there any connection at all with how dry the outside is?

2) a damp specialist said the chimney breast plaster would have been in contact with the floor, and has gone on to recommend a breathable plaster membrane. I'm slightly sceptical because some exposed brick behind the plaster is bone dry.

My view was to fix the concrete slab first (membrane and level) and perhaps re-render the chimney breast; then monitor and take stock...

I do want to get to the root cause of the problem rather than covering the symptoms with specialist products... Hope that makes sense...

Appreciate any feedback and thoughts.

Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local