Concrete floor damp

[pkeech]

Hi, my first post after stressing about damp issues since buying a property last summer.

Here is the situation:

1964 bungalow
Concrete Floors throughout
Bitumen adhesive & vinyl tile covering throughout
Damp rising up through the concrete (fluffy salts)

I believe I probably need a surface (epoxy) dpm solution.

Vinyl tiles and bitumen both tested - both contain asbestos. I am paying for the vinyl tiles to be removed by specialists. The bitumen has to stay because its too expensive to remove.

Is it possible to apply the surface dpm over the bitumen? Perhaps some kind of epoxy primer first...?

What about stud walls - would the surface dpm need to go under the studwork, otherwise all moisture will migrate to gaps in the DPM ie under stud walls?

How to link the new surface DPM to the (presumed) DPC in the walls? For solid internal walls should I expect to see a DPC also?

Finally, the house feels damp at present. We have a de-humidifier running constantly. In your experience, does the surface DPM solution actually stop the problems re damp floors and create a dryer environment? Or would another solution be better?

Sorry for all the questions - hope somebody can advise - its been abit of a nightmare discovering these problems we never knew we had! Thanks in advance for any help

 

[dazlight]

Have you had a moisture reading on the floor yet mate?
You would need to scrape as much adhesive off the floor as possible then apply a latex screed before putting a liquid dpm down.

 

[tarkett85]

any pre 1965 house didn't need a dpm by building regs so chances are very high you don't have one, ANY floorcovering requires you to have a working dpm whether a sheet set under the concrete or asphalt over the surface although asphalt is quite soft and will prevent you fitting tile or wood onto it. The best way to fix is to replace the full concrete base with a working dpm and either allowing it to dry naturally prior to flooring being fitted (takes roughly6-12 months) or waiting a minimum of 30 days then applying a paintable surface membrane which actually makes your concrete stronger this is due to it taking longer to dry out increasing it's compressive strength but preventing moisture ingress above said membrane, the subfloor needs to be clear of contaminaints so the bitumen will need removing prior otherwise it will fail, you then need to prime it and self levelling compound over with a suitable product preferably water based as they are generally much stronger than latex's and allow you to fit any floorcovering you wish. The only way you can check this and you MUST is using a moisture meter similar to this http://www.ebay.co.uk/itm/TRAMEX-WO...114?pt=LH_DefaultDomain_3&hash=item2c6a87b6f2 to find the dampest area then placing a hygrometer (one of these) over ithttp://www.ebay.co.uk/itm/Tramex-Hygrohood-/190565311208?pt=LH_DefaultDomain_3&hash=item2c5e93e2e8 it will give you a reading in RH% the only test recognised by british standards it must be below 75% for any flooring except wood which needs to be below 65%. Sorry for the bad news I am a flooring installer of over 15 years and regularily attend new training courses but there isn't a quick fix as yet sadly would make my job easier. Hi DAZ might get into an argument over dpm 1c

 

[dazlight]

1st thing is you can remove the tiles yourself. Go on the abestos website. It's low risk.

 

[pkeech]

Tiles are up now - Shield came in and lifted them. I might have a go myself in other rooms tho...

I can't dig up and relay the floor... it's just not in the budget.

Does anyone have any further suggestions? From tarketts post it seems like surface dpm is only for new concrete, and is unsuitable for old floors with no membrane...

Does anyone else have any other suggestions?
thanks for your help!

 

[dazlight]

The system I do alot and works. But I only do it in the right conditions its a screed liquid dpm then screed again. I do this before laying LVTs ( Karndean, amtico etc )

But all depends on where the house is and how high the moisture reading is.

 

[tarkett85]

the only other way is asphalt it or replace the concrete with a working dpm, asphalt is easier and cheaper short term although you can't bond solid wood to it.

 

[OnLineSupplier]

Have a look at this combination of three products:

1. a two coat paint on DPM
2. followed by primer
3. followed by thin bonded waterproof screed

DPM
********
Primer
*******
Screed
*********
Mark