Overboarding with Ply - WPB and BS standards - Tile Advice

[SteveyJ]

Hi all
Quick question about overbarding with WPB, I have been buying my WPB ply form a timber yard for ages now and the prices keep getting higher and higher etc and now the stuff there selling me isn't even stamped, and isn't as good quality as it used to be so guess not from a quality Norweigen supplier. Looking and asking about the spec they say it is WPB as come with the standard of EN-636-2 which mean can be applied in humid environment and wet if treated on edges etc.

So it got me thinking if this isn't stamped quality ply anymore what is else where, so it got me thinking what is the difference between Spruce ply WPB and and hardwood ply.

This are examples of the Spruce:
http://www.travisperkins.co.uk/p/22mm-sprucefloor-wbp-2400-x-600-x-22mm-pefc/886904/3893617

http://www.wickes.co.uk/Wickes-Structural-Spruce-Plywood-12x1220x2440mm/p/164537

And example of the hardwood:
http://www.wickes.co.uk/Wickes-Non-Structural-Hardwood-Plywood-12x1220x2440mm/p/110116

As you can see all have exactly the same reference code for WPB (EN636-2), so wondered on peoples thoughts. I know about cement based boards, no more ply etc, but wondered what the difference is between the types with regards to our job of tiling on to it, and being able to take adhesive, ditra mat etc. I know that the spruce can be used as shuttering as the wickes advert states but it is not purely shuttering ply and is the same as the spruce from Travis.

Thanks Steve

 

[Time's Ran Out]

For me the plywood is there to provide strength and stability to the substrate!
With Ditra, Hardi and Wedi boards there is no reason to want to tile direct to any plywood!!

 

[Simons70]

Plywood=wood=work for ever(at least 100 years),expansion caused by water,moisture,etc.

 

[White Room]

Plywood=wood=work for ever(at least 100 years),expansion caused by water,moisture,etc.

What ???

 

[Dougs Third Go]

What ???

I think Simon is saying not to use plywood Mark,,could be wrong though

 

[Stef]

I think Simon is saying not to use plywood Mark,,could be wrong though

That's the way I read it Doug.

I very rarely tile direct to ply now as there's too many issues with it & there are other far superior products out there..

 

[SteveyJ]

For me the plywood is there to provide strength and stability to the substrate!
With Ditra, Hardi and Wedi boards there is no reason to want to tile direct to any plywood!!

Hi thanks for all the replies. I have never used Hardi / no more ply, but have never had a reason to to be honest, as not had issues with ply myself. I find ply a good option as if there are T&G boards installed and been repaired previously and/or at different heights, damage, level etc this is no good to go onto with Hardi, so ply gets laid. (Different option if chipboard is the substrate). To be honest I don't like the idea of adhesive on T&G boards directly either for Hardi due to other adhesive or varnish on them over the years, and if you remove the whole floor your going to have to lay 22or maybe 18mm poly anyway, so it goes back to my question about the type of ply.

Timeless John, I agree with what your saying but if a floor needs extra strength added to it, then I would over-ply, and then lay ditra on top using af100. So my question is what should board would be best to get according to the types available?

 

[AliGage]

I've lost the question over this post. Are you asking what the difference is between spruce and hardwood ply??

Spruce - generally quick growing softwood is used (cheaper option)

Hardwood - dense wood grown for a lot longer therefore generally more expensive.

The standard that qualifies ply as WBP is nothing to do with the type of wood used, its the quality and bond of the glue used to layer the sheet. Its this standard that determines if the lamination of the wood will qualify to be used in damp, humid conditions or areas subject to moisture, steam etc.

All of which is irrelevant in my opinion as water and damp will rot, deteriate and manipulate wood regardless of spruce softwood or old english oak.

 

[Stef]

^^^spot on mr guage^^^

 

[AliGage]

Thank you Stef

 

[SteveyJ]

I've lost the question over this post. Are you asking what the difference is between spruce and hardwood ply??

Spruce - generally quick growing softwood is used (cheaper option)

Hardwood - dense wood grown for a lot longer therefore generally more expensive.

The standard that qualifies ply as WBP is nothing to do with the type of wood used, its the quality and bond of the glue used to layer the sheet. Its this standard that determines if the lamination of the wood will qualify to be used in damp, humid conditions or areas subject to moisture, steam etc.

All of which is irrelevant in my opinion as water and damp will rot, deteriate and manipulate wood regardless of spruce softwood or old english oak.

Thanks for this Aligage, that does explain it. Can I ask then what you would do if you don't like or use ply? Do you use the hardibacker board, do you use wedi, or what? If you were to lay a floor in a bathroom with T&G base what would the steps you would take to ensure a crack free and solid installation. As I've said before always used ply before and never had a problem but maybe I'm behind with the times and just being old and stubborn and need to move forward?
Cheers Steve

 

[AliGage]

Sorry for only just catching up with this now.

My level and choice of prep would depend on a few variables from budget, height restrants, levelness and stability of substrate i'm over boarding.
I can run through a typical example?

Bathroom floor, T&G (MR) chipboard, deflection free and no more than 5mm out of level.

Ensure floor IS deflection free and over board with 6mm hardie backer board. Glued and screwed using 1" screws.
SLC floor area to bring level.
Glue Ditra matting.
Ready for tiling.