Re-tiling en-suite

Tell me how

Hi,

I am replacing the tiles (and shower unit) in en-suite.
Current tiles were put straight on to floorboards when the house was built. Tiler has advised me that a piece of plywood should have been put under the tiles on top of the boards at the outset. He has advised that when old tiles are removed, that such a piece of plywood is put in place before he fits new tiles.

I intend doing this work myself, i.e. removing tiles, clearing adhesive and placing plywood on top of boards.

Planning on doing plywood in two pieces due to manoeuvrability but the split may be where a lot of walking is done.
Some questions.

Is this a pretty standard job to be done?
Is it reasonable task to undertake myself (electrician qualified way back and consider myself capable with tools)?
Should I screw the plywood direct to floor boards or try to hit joists on which floor boards are secured (if so, may be floating floor)?
How dense should I fit screws (6" square or 8" or 12")?
How concerned do I need to be about checking levels of board or will tiling accomodate some unevenness?
Is 6mm ply best used for this (is going to result in increased step up in to ensuite (by 6mm from current level)?

Thanks for any advice.

Sleeper12

Whatever about removing the old tiles, adhesive & grout I would leave the plywood for the tiler to do. You won't save much by doing it yourself & by doing it you let the tiler off the hook if the tiles crack, break or pop up a few months down the road. If you do the prep work for the tiler then you take responsibility for any movement under the tiles that causes damage in the long term. Tiler can't be responsible for movement & tiles breaking if he didn't do the foundation himself.

Tell me how

Sleeper12 wrote: »

Whatever about removing the old tiles, adhesive & grout I would leave the plywood for the tiler to do. You won't save much by doing it yourself & by doing it you let the tiler off the hook if the tiles crack, break or pop up a few months down the road. If you do the prep work for the tiler then you take responsibility for any movement under the tiles that causes damage in the long term. Tiler can't be responsible for movement & tiles breaking if he didn't do the foundation himself.

Tiler asked me to have that done, he suggested id get someone in if i wanted to....

I'll suss out scope of this when have removed old tiles, it is a valid point you raise.

lgk

Might be better remove the floorboards from that area and replace with 18mm ply, with and joins centred over joists or with bracing underneath to join the two pieces and restrict movement.

salmocab

Fix the screws every 100mm your a sparks don’t ever use inches again. I did it in mine, obviously use short screws that don’t go through the floor board in case, think I was told you could use certain nails, ring shank or something like that they were called but I’m not sure on that.

mick121

It is important to use wbp ply for moisture resistance,6mm will do and screw down about every 100/120 mm.its a handy job.use 3.5 X 25mm screws as they won't pop through the underside of the existing floorboards

Rows Grower

6mm plywood is the thinnest you can use for the job you are doing, a thicker sheet would be better.

Avoid having the joint of the plywood in an area where there will be foot traffic obviously.

Use a few lines of a good bonding adhesive (Tec 7, Grip Fill) on the underside of the plywood as well as screwing into the joists if you can hit them.

About 6" square is plenty for the screws.

The plywood should be fairly level but the tiler can cover any slight dips, there should be no bumps in it.

Dr_Colossus

As others have said but instead of plywood I'd go with magnesium board, water resistant, solid and a better surface to tile on than plywood.