Laying engineered flooring on concrete floor

Page may contain affiliate links. Please see terms for details.

Spinney

Bimbleur extraordinaire
Location
Back up north
Anyone done this?

I've bought underlay with a damp proof membrane. This is foam with black plastic backing, and the backing sticks out about 15 cm from one edge of the foam, to provide an overlap.

My question is - I presume the strips of underlay have to be taped together to provide proper damp proofing. But with what? Is duct/duck tape OK? No instructions forthcoming from the people I bought the flooring from!
 

Globalti

Legendary Member
I would use duck tape or any broad vinyl tape. Screwfix have this.

But go and ask on DIYnot.com
 

Rohloff_Brompton_Rider

Formerly just_fixed
I've done thousands of square metres of flooring including engineered and real wood, I've never taped the underlay. Most f the time I use either the white foam or green recycled stuff. Never had any issues.
 

tadpole

Senior Member
Location
St George
Just buy a big roll of Heavy Duty sheeting (1000μm thick 2m wide or 4m wide) and use that in addition to the plastic backing foam. No faf, no taping and does a better job. I laid the wood floor in my house 10 years ago and at my church, 2 years ago using this system (and a 6mm plywood sheeting to even out the bump), We've had no problem.
Edit my μ vanished and became an m
 

Chromatic

Legendary Member
Location
Gloucestershire
Just buy a big roll of Heavy Duty sheeting (1000m thick 2m wide or 4m wide) and use that in addition to the plastic backing foam. No faf, no taping and does a better job. I laid the wood floor in my house 10 years ago and at my church, 2 years ago using this system (and a 6mm plywood sheeting to even out the bump), We've had no problem.

That should certainly stop any damp getting through.:thumbsup:
 
OP
OP
Spinney

Spinney

Bimbleur extraordinaire
Location
Back up north
there should be a damp proof membrane under the floor slab to stop the concrete getting wet.
Thanks all.

Yes, there is membrane under the slab - having taken the skirtings off I can see the edges! No apparent damp in the concrete, but all the instructions with the flooring say use underlay with a DPM, so I am doing so (then they can't use that as an excuse should there happen to be anything wrong with the floor!).
 

threebikesmcginty

Corn Fed Hick...
Location
...on the slake
If you don't mind me asking, why are you putting an engineered floor over concrete, surely battens would be ok, you've already got a self-supporting structural floor with the concrete?
 
If you don't mind me asking, why are you putting an engineered floor over concrete, surely battens would be ok, you've already got a self-supporting structural floor with the concrete?
Because it's easier..?
(Next it'll be the "Why not use plywood?" question...:popcorn:)
 
Top Bottom