Laminate flooring over damp floor

[Melanie Johnston]

Could I have some advice please as my plans have gone a bit awry.
A section of laminate flooring in a downstairs room appeared to have lifted and unclicked itself. I took it all up yesterday to investigate what was going on. I thought it was possibly due to damp and a rubbish DPM.

When I moved in 4 yrs ago I was told by the owners it was a concrete floor. However having lifted the laminate it’s actually a mix of parquet floor (surface damp and powdery) and thick plywood. There’s also a small area of crumbled concrete where the original hearth must have been.

I was originally just going to put a DOM/underlay combo down but now I’m not sure as the majority of the floor is wooden. The main damp area is wooden and about 1 sq m in a 15 sq m room. I’d be grateful for any advice

 

[bobasd]

why not post photos, eesp of the hearth area?
the laminate has tented due to moisture pressure and/or lack of room to expand.
most probably from moisture coming up from below the hearth surface.
but if the sub-floor is a mix of ply and parquet then it seems to have been originally laid wrong.
does the concrete floor itself have a DPM?

 

[Melanie Johnston]

Photo’s for your viewing pleasure....

 

[foxhole]

Rip all the timber out, add dpm and sheet ply if you intend to lay laminate again?

 

[bobasd]

thanks for the pics.
is this room a total area concrete floor or is it a mixed solid and suspended floor?
are the surrounding rooms solid or suspended?

you will have to lift an remove all floor coverings and underlayment.
the hearth will need digging out to 300mm min deep.
ther's indications of what maybe damp on the chimney breast face - strip the wallpaper from the chimney breast to see if its concealing damp/salts etc?
why not remove the large vent screen an shine a light inside the circular vent looking for soot/rubble/vegetation?
any signs of damp on the skirtings you've removed?

you've got what looks like true dry rot - with possibility its a weird kind of wet rot?

when youvedone whats suggested then post more pics please

do you have any plans for this room floor and walls?

 

[Melanie Johnston]

Thanks all. The rest of the floors are possibly laid on concrete. It’s parquet in the hall and other front room and quarry tiles in the back room. All original 1900’s Floors. I think this is more than I can handle on my own so time to check out my overdraft and get the professionals in.

 

[bobasd]

doingwhat i suggested is very average doable with a few simple tools and a bit of sweat equity.
no skills needed - just slow and steady lifting the floorin in manageable bits.
have a helper or get someone to labour with you.
if you have time, and average fitness just do bits every day or every other day.

this way you will save some money and we can tell you whats what so you dont have to solely rely on any professional explanation.

 

[dazlight]

I’d look into Ashpalt on that floor.