F.A.O builders, dampness rising

chappers

teneighty wrote: »

If I could just chip in. You are trying to complete the puzzle with half the pieces missing.

1. You need to establish the wall construction...probably cavity
2. Position of Damp Proof Course?
3. Position of external ground level and internal floor level
4. Note the pattern of damp readings to try to locate source.

Once you have all the information draw a simple sketch section through the wall, that will help you understand how the damp is bypassing the DPC or where else it might be coming from.

Chances are if it is a 1970's build it will be a cavity wall with a damp proof course. It is possible that the DPC is bridged, debris in cavity is quite common, internal floor membrane not lapped to wall DPC so plaster bridges DPC etc. etc. etc.

Until you identify the actual cause then any remedial work is just guesswork.

I would second that.

You say that the stuff you pulled out was dry, it looks quite damp down there to me, what is at the base of the channel and how does that level relate to the damp course(have you identified that yet)and or the internal floor level.
If that level in the channel is above your floor/DPC level I would dig it down some more and then just leave it and see if the damp starts to improve next spring.
If that is open ground in that channel, then there is no need for it to be filled with anything, dumping a porous material on top won't improve the drainage

no1catman

I have a slightly similar situation. Hall wall - discoloured wallpaper, and coming off the wall a few steps up the wall.
Had a builder come out to look at it (after lack customer service from a specialist), pointed out the drive was level with the damp course. He arranged with his specialist sub-contractor to view the problem. Impressed, with me, and his damp meter - had a couple of readings of 100%, and others in the 70s.
Will be thorough judging by the layers to be put back on after it's taken back to the brick work.