ply over parquet floor

[Roofus]

Is it safe to fix 4mm or 6mm ply over an old parquet floor and if so what would I fix it with and at what spacings.
I only want to carpet the floor afterwards.
Parquet floor is original and stuck down with bitumen type stuff on to screed and is sound.
I want to ply over as I have removed some blocks and cut into the screed to lay some heating pipes.
I am now worried as a friend told me that fixing ply over a wood floor could lead to problems, any help greatly appreciated.

 

[WoodYouLike]

It can only lead to problems if after you installed the plywood you use a carpet underlayment that contains a DPM.

You can glue down the plywood with flexible adhesive if you cut the plywood sheets smaller (so not installing a 8' x 4' in one sheet)

 

[Roofus]

Many thanks for that.

Could you recommend an adhesive and a maximum size of ply sections to lay.

 

[WoodYouLike]

Basicoll PU650-SE would suit.

As for the max size: appr 50 x 50cm, and preferably diagonal installed