25mm Ply & Hardi

[Lupen]

Folks,

Bought 3 sheets of 25mm ply last week... Is there any way of telling the wood I got delivered is WBP ?? It's just that there seemed to be some confusion when it was being ordered.

I planned to screw the boards down at 150 centres, but a chippy friend also suggested D4 Polyeurethen glue, which sets like concrete and expands to fill any small gaps - Do you guys recommend or not ?

The more I read the more I see advice suggesting overboard with 6mm hardi - If I get the floor rock solid, do I need the hardi ? I will be using 300x600 porcelain tile and BAL Single Part Fastflex... and the PDF on fastflex suggests ply is OK.


Any advice appreciated.

Cheers,

Paul.

[whitebeam]

Never heard of the D4, I've tiled on lots of ply and the 25mm is a good thickness...if it's rock solid then it should be fine, what area bathroom etc are you tiling..

[doug boardley]

I personally prefer not to tile straight onto ply as you can get warpage and leaching if moisture gets to it.

[Rich]

I would personally overboard with a cement board for piece of mind, like Doug I dont like tiling straight onto ply as I have spent a lot of years putting other tilers ply floors right and haven't seen one fail using a cement board on top. If I am left no choice and have to tile directly onto ply, I use a 2-part adhesive.