Damp under lino in lean to conservatory…solutions…

We had new lino put down in the kitchen (all OK) and in the ‘lean to’.
The lino’s gone all baggy in the conservatory, and the fitter came out today and lifted it, and it’s green mould city…
Seems to be damp under there.

I’m sure, as it’s a cheap conservatory, there wasn’t a DPM put down. I don’t want to dig up the concrete flooring to put one down as in a few years time we want to knock it down and extend the kitchen, so the new flooring was a ‘cosmetic stop gap’ until we do that.

Can I get an ‘on top’ DPM I lay down? Or would screeding the concrete floor offer some damp proofing?

DrP

concrete is cold air above vinyl is warm and youve got condensation insulate one from the other

Can I get an ‘on top’ DPM I lay down?

That’s what the lino was doing. I think your only solution is either put more heat into the conservatory to raise the concrete temp or to dig it up and relay with both insulation and a DPM.

Project: would that thin foam you can lay under wood laminate flooring help?

What Project said ^^^

Insulate between lino and concrete.

If a few years is 1 or 2 then I’d just whack some cheap lino down and live with it.

The cheap sods that had our house before us had laid lino on top of thin plywood (prob 3mm I forget now).

Did the same as yours but not as mouldy…

Liquid DPM* (preferably a two part) and compatible** latex mix on top. Don’t know if your vinyl “runs” through to the conservatory so you may have to have a joining strip if there’s a change in level.

*If you can find anyone with a moisture meter, check measurements. If it’s too high, you may have to take more remedial measures.

**This is important – as you need to be sure the latex will bond to the DPM so getting a “system” from one manufacturer is advisable.

You could probably do the DPM yourself with a trowel and roller, but the latexing is probably best left to an expert.

The lean to is separated by an ‘outside door’. So not in continuation with the kitchen.

It is the cheapest lino the store had (£7 per m2), but still don’t want it sagging…

I’ll look into the advice above, ta

DrP

Put some heat into it.

Is your conservatory heated? If not, then no matter what you do, I’d expect there to be some mould after a year or two.

The problem is, unless you do something with the conservatory ceiling (at the least), you may as well throw £20 notes out the windows as try to heat it.

Define sagging OP. If the lino sits on the concrete, how can it sag?

Well, it’s ‘bumpy and loose’. Not ‘tight like a tiger’.
The lino only went down 2 weeks ago…

DrP

The lino only went down 2 weeks ago…

Which suggests quite a bit of moisture coming through (as the lino acts like a plastic DPM and traps everything – making the adhesive fail and the vinyl bubble up).

Get hold of or hire a Tramex or other accurate meter. (Or go to a wood flooring shop – they might lend you one if you pay a deposit and pretend you might be buying some timber.) Make some measurements and go from there. 2 weeks doesn’t sound very long, but if there’s moisture coming through the screed, it’s plenty enough time for the vinyl to fail. If it’s really bad…i.e. screed without a DPM, you may have not other option other than to, say, tile it with something porous that will allow the moisture through.

Dig up the wife and bury her somewhere else !!

you mentioned that you took up Lino and put down vinyl

marmoleum is breathable (as long as you don’t polish it) whereas the vinyl won’t be

Sorry..I ripped up OLD lino (didn’t like the style) and put down new lino.

I wonder if there’s been a recent leak, as the old lino seemed (technically, not cosmetically) fine.

DrP

Lino or vinyl?

EDIT: the new AND the old stuff?

Hmmm… now you’ve got me….
Not sure…

I just assumed it’s lino – it was ona roll at the carpet shop warehouse, and was cheap, and looked OK..
Any clear ways to tell? I could ask the shop I suppose!

DrP

you need to know if its water coming up or condensation. you can do something about the water coming up – cover it in vandex (waterproof concrete)

was the old lino thin and hard and is teh new stuff a soft spongy absorbant `mould will love to grow here’ type.

in our dampy basement place we have loads of vandex and a tiled floor. edit – its not dampy any more.

was the old lino thin and hard and is teh new stuff a soft spongy absorbant `mould will love to grow here’ type.

Pretty much….

I’ll lift it up, let it dry out, and assess the situation..

DrP

this? It’s breathable and warm underfoot – it’s full of win 🙂

Its likely that the slab is damp (above 75% RH) and the moisture is condensation forming against the impervious sheet flooring as that warms up either by heat in the room or just sun on the floor. As long as the floor is sound a liquid applied dpm such as RIW should work. I imagine the bubbling you are seeing is expansion of the sheet where it is no longer stuck down to the substrate. I would say that the floor layer should inspect the floor for suitability including checking its moisture content and only lay it if he accepts the floor is ok to lay. Perhaps check their T&Cs to see what you agreed to! If your old lino floor looked ok it maybe because lino gets harder with age and perhaps it was just rigid and hence looked ok? Of course check externally for leaking rainwater pipes etc.

Or put down cheap slate… Worked when we took up a dry old composite utility room floor and put down posh vinyl. Bubbled after 2 or 3 weeks..

Knock it down – end of problem – use concrete as base for bike store.

or

Some Ikea decking:

http://www.ikea.com/gb/en/catalog/categories/departments/outdoor/21957/

I just assumed it’s lino – it was ona roll at the carpet shop warehouse, and was cheap

Lino, proper Lino, ain’t cheap! “Lino” has become a catch all description for all manner of floor coverings.

Soo..
we ripped up the lino, and I stuck down a square of plastic sheeting in the middle of the conservatory.
It got wet underneath it – the damp must be coming up, or ‘settling’ from condensation?

So sealing around the edge won’t be enough.
Options, thoughts, ideas…please!

DrP

condensation forms on the warm side of a cold surface.

(ie, on the outside of a pint-glass)

assuming your ‘lino’ is water-proof, the condensation would form on top of it, not below it.

the best-guess from this average-at-best engineer is that the moisture is coming up from the ground. There might be some interesting vapour/condensing process after that, but we’re looking for the route cause here…

suggested bodge suggestion #1: take up the lino, and leave it uncovered, accept that you’ve got an air-moisturising floor, and buy a dehumidifier.

suggested bodge suggestion #2: dig a french drain around the slab?

actually, water coming through the concrete (it’s not 100% water-proof) hints that the ground around the slab is damp, how’s the guttering?

Probably irrelevant to your quest for damp-free flooring but whatever you do, do not get a company called Kenwood in to do any damp proof work.

My parents have had some work done by them & it has been a nightmare from start to ‘not yet’ finish. Started in June & still ongoing, plus their ‘customer relations manager’ needs a good hoof in the slats.

condensation forms on the warm side of a cold surface.

Not always….https://en.wikipedia.org/wiki/Interstitial_condensation

If the concrete floor doesn’t have a DPM under it, you’ll get water from the surrounding ground coming up through the concrete – it’s basically like a crap sponge. Our workshop has this as it was poured as a single raft with the footings. However, I installed a DPM on top of the concrete floor, so the inside is bone dry, but the underside of the DPM is damp most of the year (as you’d expect).

Personally I’d lay a DPM under the lino (possibly with a thin foam layer to provide some insulation).

Sorry, I’m being a bit fick ‘ere…

You say I should have it as:
Lino
Sponge
DPM
(all the above three items being loose laid?)
Crappy concrete?

Would there be any merit in laying a flexible floor compound to act as a waterproof barrier, and then stick the lino to that??

DrP