Damp under concrete floor? Or cold soil?

[doesitmatter]

After a leak in the shower and horrible mould, I stripped everything back to the suspended timber floor and found that the adjoining room, the kitchen, has a concrete floor.

It appears there's no DPM under the concrete floor and the soil/sand under the concrete floor feels wet, though less wet than it was a month ago when the shower was leaking. I also took up some floor further along, where there wouldnt have been a leak and it felt damp too.

Is this something I should be worrying about and need to get a damp specialist in? Or, am I where I am and if there's a problem, I'll need to rip up the concrete floor anyway?

The timber floor is sat on a concrete bed, level with then bottom of the image and around a foot below the kitchen floor, there appears to be a concrete base too (I used a skewer to check).

 

[tell80]

Hi,
Your information is confusing, & your pic tells vey little - perhaps you would take pics showing more context in the bathroom and the kitchen and a pic showing the ground level outside?

 

[doesitmatter]

Cheers tell80. I include an image from outside, the kitchen wall where the pipes enter from the shower room into the kitchen radiator and a little map of it all.

 

[tell80]

Thanks for the pics and sketch. I'll try again.

Starting outside:
The ground level seems too high.
The render should not be in ground contact. You can see damp staining rising behind the render, & a previous repair.
Why not Cut away the last 50mm of render in ground contact?
The metal angle bead at the LH window is rusting. The other angle beads - reveal & head -are also perhaps rusting too?
The hose bib has cracked the render.
The w/m(?) has a discharge pipe thats been codged into the square down pipe - is there access to a gulley?

Pic 244.5 shows what appears to be penetrating damp on the wall - there might be more damage behind the rad & the skirting? But where is this pic on the sketch? Is it back to back with the bathroom pic?

Is the suspended floor ventilated - how?
The bathroom has a codged together joisting - i can see damaged wood thats been used as packing, is it rotten?
Where do the WC and waste pipes drain to?
Underfloor or in the wall wastes should be glued not compression.
Elec cables shouldn't touch copper pipes.

About the kitchen:
The outside wall might have damp damage showing on the kitchen wall.
From what you say about the floor then lifting whats in-situ, and correctly replacing it is straightforward.

 

[doesitmatter]

The ground level seems too high. - It is. I fact, the conservatory and garage are both 150mm above even the kitchen floor. Definitely doesnt meet modern building regs.
The render should not be in ground contact. You can see damp staining rising behind the render, & a previous repair.
Why not Cut away the last 50mm of render in ground contact? Cut away and repair? Or cut away to let breathe? My partner would love to remove all render but I've explained it's not that easy.
The metal angle bead at the LH window is rusting. The other angle beads - reveal & head -are also perhaps rusting too? Thanks, I didnt realise that's what it was. And you're correct, the other side is showing rust though.
The hose bib has cracked the render.
The w/m(?) has a discharge pipe thats been codged into the square down pipe - is there access to a gulley? There's actually a pipe next to it (hidden), which discharges into the same gulley as the rainwater, then into the sewer.

Pic 244.5 shows what appears to be penetrating damp on the wall - there might be more damage behind the rad & the skirting? But where is this pic on the sketch? Is it back to back with the bathroom pic? Yes, the 407.2 and 329.1 are either side of the wall. I am hoping the flaking is damp from many years of leaking.
The shower was not tanked in any way. It was tiled straight onto a plastered and water also leaked down the front of the shower between the non-siliconed door and shower base. On the other sides, they tiles straight onto ply.
Not sure about the skirting, it appears fine but the damp and heat has brought the skimmed plaster away some time ago but it's bone dry behind.

Is the suspended floor ventilated - how? Air bricks. I have stuck a borescope as far as I can along the floor under the room next to the shower and timbers look okay, as do the floor. The plan is to one day pull it up and check where the gaps are, plus insulate & install underfloor heating (without connections) but not yet due to the mess/cost of it all.

The bathroom has a codged together joisting - i can see damaged wood thats been used as packing, is it rotten? No rotten joists, thankfully. Someone appears to have cut away some timber to fit the waste trap & pipes, then used a breezeblock to prop up the joist, as well as a file. Ridiculous.

Where do the WC and waste pipes drain to? They end up in the gulley but first going through another gulley which is under the conservatory. I may know more tomorrow when I remove the toilet and replace the subfloor.
Underfloor or in the wall wastes should be glued not compression. I didnt realise it was necessary in domestic as it met regs but thanks, it makes sense to change that.
Elec cables shouldn't touch copper pipes. I know. Absolute farce whoever did that. The pipes feeding the original shower are the same and sit near the rear box of a lightswitch. Honestly. It goes to a lightswitch, so I may cut/extend it myself and run it away from the pipes.

About the kitchen:
The outside wall might have damp damage showing on the kitchen wall. I believe it does. I think whoever did the patch job did a crappy job.
From what you say about the floor then lifting whats in-situ, and correctly replacing it is straightforward.

Massive thanks. You have identified a few things I need to consider, some which I had thought about but skipped over a little, others I didnt even realise. You've been incredibly generous with your guidance but helped hugely with some of my thinking.
This is my first ever house and we knew it was going to have issues but some of the work done by previous owners has been absolutely shocking and as a DIYer, I'd have a far better understanding of what should have been done. You should see some other issues! Ha!

 

[tell80]

1. ground levels should be 150mm below the DPC - its not always a possible but your high GL's could be introducing moisture into the house.
2. all solid floors must be insulated & poured on a DPM (membrane).
3. the kitchen outside wall I'm referring to is the wall in pic 407 - moisture could have penetrated and be showing on the inside of the kitchen.
4. to cut away contact with the ground by 50mm - then leave the 50mm of brick exposed.
5. unless the render is cracked, bulging & failing leave it alone.
6. plastic beads are now used with external S&L render.
7. you can tile on soli plaster - stud partitions do best with backer board. avoid plasterboard.
8. you need to have a detailed worked out plan for the bathroom - same for the kitchen.