Suspended timber floor preparation.

[David22222]

Hi
I have a small cloakroom/bathroom 1.2m X 1.5m it's a suspended timber ground floor with the joists on sleeper walls. I want to tile in 600 X 600 11mm thick polished porcelain.

What is best way to prepare the floor?

I am taking the existing chipboard out. There is no underfloor heating. I need the overall height to be about 32mm.

Thanks

 

[Bond]

Hi,

Such a small area, l would use 18mm exterior grade ply over joists, key surface with course sandpaper prime, 6mm hardibacker board on bed of flexiable cement based adhesive and screw. When you add tile and adhesive you will have a depth of approximately 38mm. Or if you leave out the hardibacker board you get approximately 30mm.

Hope this helps.

 

[David22222]

Thanks. What would you prime the ply with?

 

[Bond]

I generally use an SBR primer for most surfaces. For plywood I would dilute 1:3 with water.

In the way of preparation a good key with course sandpaper , vacuum dust, and clean down with damp sponge.