Damp proof course above internal floor level

Jeepers...

Is the main floor suspended or solid?

Not sure what the best solution is, but there MUST be ways of sorting this. Might need someone slightly more specialised than chust a 'builder'...

But, I'd have thought that a couple of possible solutions could be; angle-grind a slot a third to half-way into the brick mortar line chust under (or above?) the slate DPC, and mortar in a DPM which is then taken to below the floor level. This would need doing in stages - short lengths - so's your house doesn't suddenly drop down by 6mm...

Or, the damp wall up to the DPC is tanked using a cement-based tanking slurry. There are products available these days which will hold back chust about anything.

Neither is a major task, I wouldn't have thought. Both are potentially even DIY.

Your engineered floor ain't going to like a damp edge for too long.

 

The problem isn't the height of the DPC. If as you say the walls are cavity then the problem is the cavity, it must be full of carp allowing moisture to travel across it, or you have a raising damp problem, if the latter it will need addressing properly not some diy bodge.

 

'Don't Panic'
First thing to find out is where is the moisture coming from? If the walls are soaking as you say it sounds a bit more than the normal 'rising damp'. Can you get under the floor to have a look and inspect the solum / joist ends, internal walls. Do you have any problems with the drains leaking around the house? is there a water course anywhere nearby? Do you have a leak or loss of pressure in the mains water supply? All of these things can contribute to the problem.
It could be as you say that the house simply does require a new damp course. Will need some more info to properly advise, is it a semi, detached, or terraced house. Brick or stone exterior/ internal walls, are the internal walls affected as well as the external walls? Where is the external damp course? are there air bricks around the exterior of the house.
99% of these problems are fixable, its just down to cost.

 

Alex, where is the "water staining and mould"? Is it mainly behind the skirting, where the one course of below-DPC bricks are? (I would expect some damp and staining above that level too, as the interior plaster would be conducting the damp up a bit.)

But, if it looks as tho' this damp is coming from that particular row of bricks, then surely that's the problem chust there; something weird went on in that the DPC was positioned too high or the floor installed too low! ( tho' I have to admit, neither makes much sense...)

You also say this gives you "soaking wet walls and skirting", which sounds a bit dramatic. Are the wall really 'soaking' behind the skirting, and if so, is that the only place they are?

You have removed 2' of plaster, so you've exposed the bricks for a footandahalf above this DPC? In which case it should hopefully now be pretty obvious where the damp is coming from. If it is only present on the row of bricks below the DPC, then I think you can be pretty sure what the issue is.

I guess you could add to the possible solutions - fit a new DPC below the floor level, but - man - that ain't gonna be easy. Access will be tricky, and you'll have to either cut right through the whole thickness of brick, or else rely on an injected liquid DPC. The latter might work, but I think I'd prefer a membrane that'll properly isolate that row of miscreant bricks