I got a pca-type surveyor in for damp/moisture diagnosis and a wall tie check, but taking the proposed solutions on the damp side with a pinch of salt. I’d like a few extra thoughts if possible please.
~1930’s semi, cavity wall construction, built with no DPC, ~50mm cavity, insulated with blown fibre. Insulation (from wall tie check) appears bone dry. In my personal opinion, if it’s useful to know, the house also potentially has externally applied (StormDry like) masonry cream. The house floor sits ~1m above ground level on all sides – aside from party wall. A previous owner has applied a (waste of time most likely) retrospective chemical dpc externally around the floor level of the house. The rear wall of the house is quite exposed.
View attachment 274786
The moisture/damp appears to be around the perimeter of the concrete floor. It is causing noticeable staining/damage to the side elevation. Going by what the damp surveyor has said and my own reading, I suspect the solid floor base material is wicking up moisture which is travelling through the concrete floor. It then hits the asphalt layer and is pushed sideways and comes up the plaster in the walls. Although, feel free to tell me that moisture is unlikely to be wicked up that far and the moisture is coming from elsewhere.
The damp surveyor has initially proposed extending the asphalt dpm with a plastic dpm part way up the walls and replastering. However I feel this may just mask the problem and the moisture still travels up the walls (potentialy wetting the CWI). I can think of two other possibilities that don’t just cover up the damp:
1-Remove the asphalt layer and allow the concrete to breathe naturally rather than pushing the moisture out into the walls. Or will it be far too wet? If I do this, how do I handle reflooring?
2-Dig up the floor and reconcrete with a plastic DPM? (use the occasion to insulate and install UFH)? How do you prevent the moisture travelling up the wall here/'lap into the DPC' (as there is no DPC in the walls)? Or can you retrospectively insert a plastic DPC / apply chemical DPC cream?
Thanks for any thoughts in advance!
Just done a quick measurement assuming the overflow runs in/out of the same height/course of bricks.Where is "internal floor level" on that wet wall?
Thanks. Will arrange a drainage survey / check (access is poor) and do a thorough listen with a helper on the water inlet.Let's suppose the solid floor was very wet
The wall would look like that
Let's suppose there was a leaking pipe in the floor
It would make the floor very wet.
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