Laying plywood floor

jpmagoo

I'm lifting 18mm plywood (2400x 1200) which is nailed to 22mm x 70mm batons which are nailed to a concrete floor at 400mm centres. I plan to lay 50mm flooring grade insulation on top of the batons then relay the ply and then glue reclaimed parquet on top. Any suggestions on how to secure the plywood? Was thinking of using 10 x 140mm hammer fixing to go through the insulation and into the concrete and ordinary screws to go through the insulation and into the batons. The area is about 45sqm and I want the ply as rigid as posible. Anyone got advice??

Calahonda52

When u say flooring grade insulation what exactly do you mean?
will it sag at 400 centres
Why not take up the batons and go fully supported on the concrete floor.
Make sure you don't perforate the dpc in the floor when drilling

Lumen

Would you not just use plywood-faced insulation? Like Kingspan TR31. It mean, it's not intended for your application but it seems to match what you're trying to achieve.

Agree with removing the battens, assuming the concrete subfloor is level. If not, maybe levelling compound?

jpmagoo

Calahonda52 wrote: »

When u say flooring grade insulation what exactly do you mean?
will it sag at 400 centres
Why not take up the batons and go fully supported on the concrete floor.
Make sure you don't perforate the dpc in the floor when drilling

I have the insulation and I have the plywood so I just want to know the best way to fix it. Kingspan do a heavy duty insulation for flooring which I am told is denser than wall or ceiling

jpmagoo

Lumen wrote: »

Would you not just use plywood-faced insulation? Like Kingspan TR31. It mean, it's not intended for your application but it seems to match what you're trying to achieve.

Agree with removing the battens, assuming the concrete subfloor is level. If not, maybe levelling compound?

have the insulation and the ply so just need to know how to fix it. Been advised to lay insulation on top of battens to allow some airflow and prevent condensation.

Lumen

Right, OK.

So assuming the battens are laid on flat (rather then edge) you have 68mm to fix on to 22mm, which means a 90mm screw will overpenetrate due to the countersinking (very bad!), and an 80mm screw won't have enough bite.

You could alternatively use countersunk concrete screws straight through all three layers.

Maybe do some tests.

Obvs your main constraint is that parquet floor needs a really stable subfloor.