Plywood for bathroom subfloor

[wrightyintheafternoon]

I want to replace all the floorboards in my bathroom with 18mm plywood.

My local merchants sells 2 types WBP and softwood structural ply. The WBP is described as not being for structural use but would seem to be the better option for the bathroom being WBP where as the structural plywood says suitable for humid conditions.

https://www.bradfords.co.uk/q-mark-plywood-wbp018

https://www.bradfords.co.uk/structural-grade-plywood-psw018

Thoughts please.

 

[blup]

Thoughts...

Either type would be fine, because the rating relates to delamination rather than immersion in moisture or water....in any event you would be tiling over, or otherwise providing protection to the floor. In fact the cheap non structural stuff from Wickes would probably be OK

Blup

 

[wrightyintheafternoon]

Thanks for that. The structural is much cheaper so will probably go with that. I understand the strength comes from the number of laminates and structural has more than non structural.

 

[dazlight]

Get SP101 plywood. Best plywood out there for flooring.

 

[foxhole]

18mm is too thin for tiling onto alone.Minimum 22mm

 

[John D v2.0]

Looks good to me, that structural one is the best for flooring and what i used everywhere. Does need 400 centres to avoid flexing too much.

 

[wrightyintheafternoon]

Hi All, thanks for the replies. Not tiling the floor, so gone with 18mm and 6mm ply topper before the final vinyl flooring. Will be putting noggins under each joint and also where the heaviest loads and stability will be required such as under the shower tray and the bath and toilet. Floor boards were 20mm with 3mm hardboard on top, so gained 1mm which is fine and lines up nicely with the landing carpet.