Plywood floor on concrete slab

Muddler

I am going to attempt a plywood floor. My current floor is a level concrete slab, I wonder what the best preparation is? Does it need insulation? Can input insulation down? Should there be a subfloor is OSB or similar? Or plywood straight on to concrete?

Advice/recommendations appreciated.

DOH_a

What is this for... a shed, garage conversion?

Muddler

Indoors! A flat.

Browntoa

What's going on top of the plywood ? 

Muddler

Stained and then polyurethane.

gamston

I've read about you need to have DCM between the concrete and ply, but I've put down hardboard sheets (best to glue then down) then covered with "lino" did them 15 yrs ago in 2 rooms kitchen & bathroom, replaced the "lino" couple times both areas hardboard still as good as new

Hasbeen

Muddler said:

Stained and then polyurethane.

Your going to put plywood sheets down and stain them? make sure all the screws are in a nice pattern. As unlike hardboard ply would require screws?

DOH_a

Have you taken a floor finish up to expose the concrete floor so are you replacing it on a like for like basis?

You should always look to lay a membrane on top of a concrete floor prior to applying insulation/screed/timber decking.

troffasky

Muddler said:

Does it need insulation? Can input insulation down? Should there be a subfloor is OSB or similar? Or plywood straight on to concrete?

Is the concrete slab the ground floor or do you have someone below you? I can't see why you'd bother with either insulation or DPM if it isn't the ground floor.

Depending how recently it was built, a ground floor concrete slab might have been poured over insulation. Only you can say if you can put insulation down - we don't know how much leeway you've got with regards to building up the floor level.

Hasbeen said:

make sure all the screws are in a nice pattern. As unlike hardboard ply would require screws?

That's going to be a fun job! Drilling out the concrete, inserting anchors and then somehow managing to pilot [or not] the screws in exactly the right place....however many tens of times. I suppose you could pilot the ply first, mark the concrete slab using the ply as the template, lift the ply, drill the concrete, etc, and hope you don't damage the boards in the process. I think the OP should find some other way of fixing it down, if at all possible.

Muddler

It is ground floor and around 3ft off the normal ground to my floor, you can see the damp proof membrane on the outside wall.
The current flooring is just carpet with underlay underneath and nothing else.

To lay the ply uneasy either thinking of OSB or hardboard nailed to the concrete. And then plywood on to nailed.
Or glue the plywood to the concrete direct.

Hasbeen

OP why are you doing this? 

Is it just to lay large 8 x 4 plywood sheets to stain them? 

Why not laminate or engineered wood flooring if possible?


Are you actually talking about plywood? As below?