damp but from how?

[jono5000]

Hi all

just a little advice needed as this problem is going on months and still not sorted

first noticed damp in my bedroom ground floor flat, paint bubbling on internal wall separating that and bathroom and on external wall

on the other side is an internal soil stack which is boxed in, all damp timber and toilet

anyway after faffing around, had a plumber come in to dig up vertical waste pipe form toilet going into concrete ground, I believe which must connect to vertical soil stack further down, he didn't dig around the stack itself, but in the past the soil around it has been very damp

this plumber said the soil pipe was fine but water was weeping through crumbling mortar from brickwork on external wall under the dpc

the concrete floor has a dpm but doesn't come up to meet the dpc as too small, and previous plastering was taken right down passed dpc, so this explains why by bedroom has been damaged, but still not sure how water is getting in


on the outside the dpc is visible at least 2-3 bricks above all grass, but exactly where the damp is coming through the wall there is white outgrowths from the bricks very crumbly concentrated just in this section and come right up to dpc, however all along the length of the building there is a small amount of whiteness

there is an inspection cover just outside my bathroom where the damp appears

the flat is 1981 purpose build, solid brick, unsure whether cavity wall or not

when replastering i will make sure plaster is not taken down to the ground, but as there is a gap between the concrete subfloor which is now full of debris, it is still damp and the problem is still there, in otherwords i do believe i need to stop this happening first, is it something I should worry about though, how can u stop damp getting through through brick work under the dpc, without digging grass away from outside or removing brickwork? (the ground floor internally is higher then the dpc)

 

[dave1953]

Hi jono5000, the whiteness your seeing is the salts within the bricks coming out, if it only happens to DPC level then the DPC is doing its job. Are you sure you hav'nt got a condensation problem, i.e.what flooring finish have you got, do you dry clothing in rooms affected, have you got a humidistat fitted in the bathroom etc etc,
For a plumber to comment on water trickling through the bricks raises the same questions, it could well be condensation. Does this happen between Oct to March or is it permanently occurring, if so then I would definately dig the ground level down and substitute with a 150mm pea-gravel border to brickwork or put in a sectional drain run off.If you cannot do this as a leaseholder of the flat I would be getting the building owner to investigate it. Sounds to me you need a Hygrometer survey undertaken to determine the evidence of condensation occurring or not. Hope this helps.

 

[jono5000]

cheers for response, however it seem to be below floor level, there is a gap between the concrete and brick work, where plaster has been applied. This however seems to be a trend all the way around the flat, but only this area seems to be affected. The remaining plaster that I cannot scoop out with my fingers is still damp.

The floor was originally lino which was pulled up months ago, leaving a screed and concrete surface. I dry all my clothes in an oversized airing cupboard. I really doubt it would be condensation.

I still think its a problem with the drainage outside and ok the fact plastering was brought down to dpc didn't help. There is all moss growing on the brickwork as it enters the grass/mud.

Which leads me to my next problem, assuming I can rule out building aspects, trying to get the management to do something about the grounds, going to be a nightmare as the company are residential owned and haven't got a clue. May have to get a quote myself, write a letter to them and let them know whats involved and present them with a bill. This is going to be fun..... Thats assuming it is that problem.