WBP to replace existing floorboards

[barberj66]

We are having a new bathroom fitted soon and I think I was to have a go at tiling it myself. When we did the kitchen I got someone in as the tiles were stone and expensive so didn't want to risk it looking rubbish.

This time however I could do with saving the money and doing it myself, I've never tiled before at all so reading up a lot and watching plenty of videos to get the basics sorted. Will be getting some help from father in law who has tiled for himself before so hoping between us we can get a decent job done.

I'm going to replace the existing floor as the floorboards are old and no good so will be ripping them up adding new noggins in and replace with 25mm WBP, can this be put down in sections and screwed down, the bathroom is tiny so I wouldn't realistically be able to work with larger sheets in there. I'm presuming if it's screwed down enough a few joins would be OK? I know the less joins the less potential movement there will be but is it acceptable to do this?

The area is only 4sqm so is tiny really.

 

[Gteuk]

To be honest this is a double headed coin scenario, one large piece over uneven joists could cause more movement from what I call the seesaw effect, where one joist is higher than others, however if it is spread over many joists and enough screws are used the anchoring will reduce said effect.

Smaller boards may emphasis the effect more localised,, saying that though each board should be glued to the next one,

Personally screws with smaller gaps 150 - 200mm to reduce movement
I always recommend an Acrylic Primer (not PVA) and a flexible tile adhesive.
If this is your first time tiling use a standard set "FLEXIBLE" Tile Adhesive and make sure it is a powder version not the ready mix mastic.
The Prime bond is highly important on a chipboard / Ply floor as the moisture will get sucked out of the adhesive without it and your floor will come up.

 

[barberj66]

Cheers for that I'll have a look in to those details you have posted and make sure I get the correct adhesive etc

 

[vinn]

Floor work is best done with all fixtures removed.
Given such a tiny bathroom why not post some photos of the floor - your idea of "no good floorboards" might be wrong, and the boards could be kept saving you from extra work?
As a DIY first timer its best to practice on a blank wall, or an old piece of plaster board, with some old/damaged tiles before going at it for real?

 

[L95]

The above two posts are certainly correct but I would also suggest priming the reverse and sides of the WBP before installing to prevent moisture coming through the reverse. I can't give you all the science bits in regards to this and I'm not too sure if it applies to plywood floors but ventilation under the floor is also a key thing to consider when tiling wood floors. But as I said, I'm not too sure off the top of my head as to whether this applies to WPB.