Glueing engineered wood to concrete floor

[JohnL24]

Hello,
I'm planning to replace the carpet in my living room with engineered wood. I've done this already on the stairs and the upstairs landing.

Once carpet is removed I plan to use self leveling compound to make sure that everything is flat and level and then apply damp proof membrane.
From there on I would add the adhesive and lay the floor.

What I wanted to ask is do need any insulation underneath? Like 20mm foam insulation boards? My big concern with adding insulation is that it would raise the floor by a lot!

Thanks

 

[motorbiking]

When was the house built? If it was 50s-90s, then there is likely to be no insulation. its likely that your floor would be very cold, without carpet.

I have a parquet flooring on a bed of bitumen, on a concrete slab and we are very much appreciating our rugs.

 

[JohnL24]

House was built in 1970.
I am wondering if 10mm XPS boards would be enough to provide decent enough insulation?

 

[motorbiking]

No - but its better than nothing. It will reduce the U value from about 1.25 to 0.75. 25mm will get that to 0.5

 

[JohnL24]

Ok so I guess I might need to upgrade to 25mm PIR boards. Found this one: https://www.insulationsuperstore.co...-tb4025-insulation-board-2400mm-x-1200mm.html

I am wondering now if 120kPa is strong enough to withstand the pressure of furniture where you have 4 people sitting on the sofa.

Also would I need to glue the PIR board to the concrete as well before glueing the wood to the PIR?

 

[Mr Chibs]

Think you’ll find when the insulation is down and your engineered flooring on top, you won’t even worry about weight distribution. It’s quite strong with distributed loads... but if you kneel on it, you will make a dent.

No need to glue unless the boards are bent. Tape up the joins with aluminium duct tape.

 

[JohnL24]

Thanks

Also would Sikabond 54 Wood Floor adhesive stick well enough to a PIR boards?

 

[JohnL24]

Well turns out that only half the room was concrete (the new bit that got extended) and the rest is this weird ?plastic/rubber? tiles that appear to be glued with bitumen I think. The tiled surface appears to be nice and evenly flat across the whole room while concrete bit has some dents and overall seems to be a bit lower.

What should I do now to prep???

 

[Mr Chibs]

Not sure on the adhesive front to those old Lino tiles... please have a read up, but I’ve a feeling the tiles may contain Asbestos fibres... But this is depending on age of them.

If you are thinking of lifting them, perhaps you should get a small sample tested.

Others will be along with more advice.

 

[dazlight]

You could float the engineered wood and less prep.

 

[JohnL24]

I already have the glue and had good results with doing the stairs and landing with it.

 

[dazlight]

Ok.
So you need to remove the vinyl tiles.
Grind off the adhesive and any loose screed.
check for moisture. The screed needs to be under 65%RH
Apply a smoothing compound if needed.
Apply a epoxy Dpm if needed.
Glue the wood.

 

[JohnL24]

Thanks I also already have the DPM liquid too so I'll add it on regardless.

I also plan to add 25mm PIR boards before glueing the wood on top

 

[dazlight]

Always the best way. We Dpm every wood floor just in case. Not sure on the PIR boards though as it used them. Can you post pics up when you do it.

 

[JohnL24]

Small update. Did some cutting and chiselling:

NOW my question is how deep are water pipes meant to be? Would they be in the concrete or under the concrete floor in the soil? I am cutting into the concrete around 50mm, to chisel it.