Help and Advice please.

[rayallen1]

Hello.
I`m looking for some advice on re-tileing my kitchen floor. The previous owner of the house laid the floor tiles directly over the floor boards they are now cracking and coming loose.

I`ve taken some up and tried removing the adhesive from the floor boards. I think It would take a very long time to do the whole room (about 25 sq meters). From what I have read on this forum I would be better off removing the floor boards and replacing It with a 18mm exterior plywood floor.

I have a couple of questions.
1. 1. Are there different grades of exterior plywood. If so which would be best.

2. 2. Would 18mm be thick enough.

3. 3. What adhesive and grout would be best for the job.


Thanks in advance for your help with this. If you think of anything else that would help me with this project I will be very grateful for any advice.

 

[danmasey]

Marine ply but don't tile directly onto that. Then 6mm hardie backer type boards on top of that.

 

[Gazzer]

The ply you require is WBP and try and avoid the far eastern variety. Easily spotted by its cheaper price and the weight of a sheet compared to the weight of quality ply.
Depending on the strength of the joists will be the only way to know if the floor will be strong enough after laying the new ply. While the floor is up you could add noggins between the joists and other methods of strengthening . If the floor is out of level its a good opportunity to fix 18mm ply either side of each joist ( sandwich the joist, Glued and screwed) This will let you lift the floor level and add a great deal of strength.
As stated above, cover with 6mm cement tile backer boards (glued and screwed) and tile with a single part flexible tile adhesive from a reputable manufacturer.