Damp in concrete floor - options?

[RogerS]

In one of our sitting rooms we had a concrete floor laid well over ten years ago IIRC and then carpetted. We rarely use the room and to my horro have now found that in one corner the DPC has failed somewere along the way and the carpet is well and truly had it...or it will have once I finish exploration.

So what are my options? The property is very old, no foundations, solid stone walls directly onto clay. Builder who did the work is long gone.

1) Kango up the corner, trying to avoid the embedded ch pipes (thinks...maybe that's where the problem comes from but they are plastic and shrouded in foam insulation so don't think so), try and make a decent seal to the old DPC, fill back and make good.

2) Synthaprufe the surface and hope that the damp doesn't migrate sideways or maybe Synthaprufe the whole floor.

3) What else?

 

[MikeG.]

Roger,

absolutely not 2......just promise me you wont do this.

I'm afraid it would be impossible to suggest a remedy without an inspection........and the next time I expect to be in Worcester is when doing Lands End to John O'Groats on my bike next year.......so if I were you I would get an architect, surveyor, or very trusted builder-friend to have a look.

He would need to satisfy himself of the detailing of the DPM/ DPC, the floor build-up, and the integrity of the pipework. I am dealing with a local case of a spring actually arising under the ground floor of a timber frame cottage......there are just so many things this could be that you shouldn't take any advice from anyone who doesn't do a site visit.

Mike

 

[Doug B]

Just a thought on the central heating pipes.

If they were leaking you would be getting a constant fall on the pressure gauge, if it`s a sealed system.
If it is a gravity system the header tank would be loosing water, which if it is a large leak the ball-valve would be continually running. If it`s only a small leak the ball-valve might not be running all the while, so tie up the ball-valve & monitor the water level over the next week.
Always do this at the same time of day, preferably before the heating/hot water comes on, as the water level changes with expansion & contraction.

 

[treeturner123]

Roger.

There are a number of possible causes. As others have pointed out and correctly advised, if the problem is leaking buried pipes, then the suggestions to check this will soon tell you. If not, then as the house is very old, I'm assuming that you had an injection DCC installed. It may be that the injection DPC has failed, though in my experience as a surveyor, this is very uncommon, unless the wall are more than 9in brick. If they are of stone then an injection DPC is not of much use anyway due to the nature of stone especially if it is an igneous stone as you find in Malvern.

The injection DPC may have been bridged either internally or externally in which case removing the bridge will solve the problem.

Finally, as you say the room is not much used, it may even be a case of condensation due to some items above plus lack of ventilation.

As suggested a local builder or surveyor with the correct instruments will be able to advise.