Damp Floor?

So... Getting new carpets fitted and the chaps came to the dining room - which used to be on the outside of the house, and we think used to be the original kitchen, but we reckon some 60 years ago an additional covered alleyway was built outside it, making a corridor into the barn at the side of the house which is now the kitchen... House is c250 years old.

Anyway, when we lifted the old carpet they found some blue plasticy stuff under it (like very thin foam - like the sort of stuff you might lay under laminate flooring), then about 3 layers of brown paper then a cement floor.

And at a few spots the paper was damp and mouldy )-:

The damp appears to be in lines where the cement looks like it's cracked - according to a local builder it's typical here to put a layer of cement over old flagstones which are on dirt - no DPM.

House insurance won't cover any work on it - I guess we got cheap insurance.

A few photos here:

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scraped the paper up last night and it more or less immediately dried. We've never smelt any sort of mustyness in that room, nor felt the carpets being damp. It's been raining here today and there's no sign of any dampness coming up...

(currently have some off-cuts covering bits of it and not noticing any issues)

We think the old carpet was there for at least 15 years, and we suspect they knew about this - there's also a few blobs of what looks like bitumen over the floor too....

So... Bit stuck here about what to do - most thoughts seem to be that if the underlay we're using is breathable (it is - local stuff made with recycled tyres and felt) and the carpet is also breathable (it's hessian backed) and wool, then we'll probably be OK. The amount of water that's come up has to be less than a cupfull over the years, but since the paper had plastic on-top, it's never been able to dry out. The walls are fine

- and there was even a lot of dry dust under the skirting boards where they were sanded down 3 years ago - so I don't think it's quite at the swimming pool level yet!

One suggestion we had was to put battons down and floorboards on-top, with ventilation grids at the ends - and while that's do-able, it will raise the floor, requiring some steps into and out of it (2 doors and a set of stairs), but others have said just to carpet it anyway, or do as previous did with paper and plastic, then the underlay & carpet?

Anyone seen anything like this before?

Any suggestions welcome...

Gordon

Reply to
Gordon Henderson
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Like you say it sounds like all it needs is porous carpet & underlay.

NT

Reply to
Tabby

OTOH you could simply put DPM under the carpet to keep the damp *out*, rather than letting it shove moisture into your house where it will generate condensation possibilities. And rot the carpet locally, and for sure stain it. DAMHIKT.

Reply to
The Natural Philosopher

All depends how bad it is. A slab that stays dry enough with porous carpet can get positively wet if plastic covered, the OP's looks a fair bit drier than that. Choose underlay carefully though, or dont have any.

NT

Reply to
Tabby

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> I scraped the paper up last night and it more or less immediately

if you wanted to "sort" it as opposed to masking it again (which could work fine) have a google for "epoxy DPM" that cold be applied to the entire surface of the floor.

Cheers Jim K

Reply to
Jim K

One thing I've found is that it can come and go - our basement floor's been dry for the last couple of years, but this year we've had a little damp coming up in certain small patches through hairline* cracks in the slab (and it has been a lot wetter this year than previous years).

  • I can't even see them, but they must be there :-)

Personally I'd seal it with something (either liquid stuff or plastic sheet), just to be sure.

cheers

Jules

Reply to
Jules Richardson

"Gordon Henderson" wrote

Not strictly meant to stop on-going moisture, but if it can't handle the quantities you've mentioned I'd be surprised:

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Reply to
TheScullster

Remove the skirting and hack off the bottom 4-6" of plaster. SBR the floor (liberally) - it is both a binder & waterproofer. Everbuild BlackJack DPM the floor (3x) - bitumen & latex combined.

Then ask EverBuild what you can put on top (I can not recall, they may say a sheet of plastic & underlay).

Tommy Walsh did that with a cement slab.

The alternative is rip it up, but it is not easy or cheap re MOT, sand blinding, DPM, insulation, cement, screed etc.

Reply to
js.b1

The sane option is to leave it completely alone. With the plastic removed it'll be far drier.

NT

Reply to
Tabby

Jim K wibbled on Sunday 15 August 2010 09:25

For that, I can recommend F Ball Stopgap F75. For carpeting, it would need no further over treatment, but for sticking tiles down you'd need to go over with 3+mm of Stopgap 300.

I used F75 and it is pretty simple if you are just going over otherwise firm screed.

However, a loose lay of heavy gauge DPM plastic overlapped about 6" at the joints and taped would probably work OK for a fraction of the price. The screed would get damp but nothing above would care.

Cheers

Tim

Reply to
Tim Watts

js.b1 wibbled on Monday 16 August 2010 17:37

The only caution I would give with using bitumen is that if anyone ever wants to stick anything else down that requires a non bitumen adhesive (eg tiles, maybe vinyl), then they are rather stuffed (as I was) and will probably have to do something drastic to get rid of it.

I'd definately go for either epoxy DPM or loose lay DPM.

Reply to
Tim Watts

You know you love asphalt covered concrete :-)

Epoxy DPM is probably the best solution, loose DPM the cheapest. Whatever, damp and carpets do not mix if anyone has any respiratory or allergy issues.

Reply to
js.b1

Bitumen sticks vinyl down nicely

NT

Reply to
Tabby

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