New Member. Need help with new bathroom floor

[jim11115]

Hi everyone.

First post here and hoping for some good advice!

I am a DIYer who has bought a wreck of a house, I need advice on tiling a bathroom. The main area I need help is the floor. I am replacing the current plywood with new 18mm ply (measures more like 20mm) The original stuff was 12mm - which seemed a bit lightweight to me and as the floor joists are sloping quite a bit I am going to put down firrings to level up the floor joists before fixing the plywood. It's an old house (circa 1910) that has moved, but there has not been any movement since work was done on this and nextdoor house (last two in a terrace) around the late 1980s. My questions are -

1 / Is my plan for leveling the floor and the type of plywood ok?

2/ I am planning to use 60cm x 60cm porcelain tiles on the floor and one wall (wall will be mostly ply - to box in pipes etc) what type of adhesive and grout should I use on the floor and do I need to put down and kind of barrier between the tiles and the ply?

Thanks in advance.

Jim

 

[Ajax123]

Your method for levelling the floor sounds fine although I might be tempted to go down the route of cement backer over the chipboard.

The one issue you will need to consider though is the engineering. 1900 through to about 1925 saw lots of changes to building practice. When you say it was built bout 1910 the joist size may be relatively small. If there is too much weight on the floor it could cause issues later on with deflection and worse still creep.