Is this marine plywood (B&Q)?

[Possom]

Would anyone happen to know if the Metsa Wood branded exterior plywood sold at B&Q is marine plywood?

http://www.diy.com/departments/exterior-plywood-board-th18mm-w1220mm-l2440mm/892386_BQ.prd

 

[John D v2.0]

Marine plywood I don't think exists any more, the eu standards are for the glue and the wood separately. If you do some research you should be able to check the levels although I can't remember off hand

 

[dazlight]

No it's not. You can't get it in the uk anymore. Even though some companies say it's Marine it's isn't.
What do you need it for?

 

[Possom]

No it's not. You can't get it in the uk anymore. Even though some companies say it's Marine it's isn't.
What do you need it for?

I had been told by a professional bathroom installer that a marine plywood floor is best in a bathroom. Then tile/vinyl directly over this.

 

[JohnD]

I have used Marine ply, it is made with selected hardwood veneers suitable for varnishing, the spec allows ordinary WBP to have plugged or live knots, marine ply looks perfect. It is noticeably more expensive. There are boatbuilders where I used to live

I don't recall what the intermediate plies have to be like, but I think it must be free of gaps.

But IIRC the glue used in WBP is the same; so if you used Marine ply you would be paying for a finer appearance, but then covering it up, so why bother?

As boatbuilders still exist, I don't see why marine ply should be unobtainable.

edit
here you are
https://en.wikipedia.org/wiki/BS_1088

 

[Possom]

I have used Marine ply, it is made with selected hardwood veneers suitable for varnishing, the spec allows ordinary WBP to have plugged or live knots, marine ply looks perfect. It is noticeably more expensive. There are boatbuilders where I used to live

I don't recall what the intermediate plies have to be like, but I think it must be free of gaps.

But IIRC the glue used in WBP is the same; so if you used Marine ply you would be paying for a finer appearance, but then covering it up, so why bother?

The WBP which you refer to, is this the name of another type of plywood?

(If so, I could ask about when I contact a timber merchant).

 

[JohnD]

WBP means "water and boil proof" meaning it is made using a glue that does not soften or come apart when wet, even when held in boiling water. When it was invented it was demonstrated at shows in a pan of boiling water. Older "Scotch" glue used to be made in a pot that was mixed up using hot water, to dissolve it, and went hard when it cooled and dried.

If you see old or cheap plywood furniture that has been left out in the rain, you will see it quickly softens and delaminates, so this was a big step forward.

Ply that is used in building is usually (always?) WBP grade now.

Even WBP does not last for ever, so it has to be sealed, especially on the edges, to prevent damp getting in. There are various qualities.

 

[dazlight]

You want a 18mm ply down then a top coat of plywood like SP101 which has glue bond of EN314-2 class 3.
Another way you could go is 18mm plywood then prime and apply 3mm fibre screed like level flex.

 

[Possom]

And would you say that 18mm thick plywood is too thin as a standalone floor in a bathroom, or should it be 25 mm thick?

 

[vinn]

"Marine ply" and "WBP ply" possibly once had some how it was built meaning, nowadays they are just any old plys with any old names.
OP, there never previously was a use for the above plys in residential work - there's even less sense now in paying out for what typically is common structural ply.

 

[dazlight]

18mm is spot on for bathrooms. Better to ply then chipboard imo

 

[Robbie uk]

As above will more than do the job. Plenty of screws at 8 inch centres and it will be tight a s a drum.

 

[Tigercubrider]

Wickes sell marine ply (1 out of about 10)

I assume that travis Perkins also do as they are the same group
I can't access the TP site to check

 

[dazlight]

It's not proper marine ply that. They just call it that.

 

[JohnD]

so when they say "Compliant with British Standard BS1088-1:2003" is it false advertising?

It's certainly very expensive for an ordinary WBP.

Perhaps you should make a complaint to Trading Standards.