Waterproof or Marine ply?

[Brad]

hi all

firstly, thanks to all of you who have taken time out to answer my questions! good on ya!

I have another......i don't quite understand the difference between marine ply, exterior grade ply and waterproof ply. waterproof ply is cheaper than marine, so is it ok to use waterproof instead of marine when you need a waterproof substrate to work from?

[grumpygrouter]

WBP Ply or exterior grade (same thing I think) is what is normally the most cost effective surface for tiling. I have never heard of waterproof ply though. Marine ply is named because it was developed for boatbuilding. It isn't "waterproof" otherwise it would not need protecting from the elements, just that the resins used in it's manufacture do not breakdown in contact with water so is more sutable for marine use.

If you need a waterproof surface to tile on then you need to think about "Tanking".

[Dave]

WPB ply.......is water,boil proof......water resistant.......as grumps sez if you want water rpoof then either tank or use a membrane or a backerboard ( something like wedi )and joint tape...

[smurf21]

marine ply is just a better make up it tends to be flatter than exterior ply( also known as shuttering ply}