Advice for bathroom floor

[NeilB]

Hello, I am planning an new bathroom in our house and would appreciate some advice on construction of the floor.

The room measures approx 2.5 x 2.5m and currently has the original 1920's floorboards. These are fitted on good solid 7 x 2.5" joists at 15" centres.
I would like to fit some 600 x 300 x 10mm marble tiles, so will need to replace the floor with something more stable.

The options I am currently considering are:

1. Remove old boards and replace with 25mm WBP ply.
2. Remove old boards and replace with 18mm WBP ply, then overlay with 6mm aquapanel. I guess this may be more thermally stable but may flex more?

Also I was planning on using BAL Rapidset flexible or BAL natural stone adhesive, but wondered if a 2 part would be better.

Any recommendations would be appreciated.

Thanks in advance

Neil

 

[White Room]

Hi and welcome.....how solid is the old floor..

 

[NeilB]

Hello Whitebeam, Thanks for your reply. The floor is really solid, but some of the boards have previously been lifted and I will need to take up a lot more for fitting all the plumbing. Also I forgot to mention in my original post that I plan to fit electric underfloor heating.

Cheers
Neil

 

[Dontiler]

Hello Neil
if your floor have no deflection and If you lifting boards then you could just change them to 18mm ply, 6mm cement board glued and screwed on top then underfloor heating, then latex ufh and fit ditra matting after, and your floor will be ready to Tile with Marble

 

[Jeff the tiler]

Agree lift boards, 18mm ply, either cement or hardi backer board glued and screw every 150mm on top making sure your joins overlap that of the ply. Ditra or Durbase decoupling membrane and you are set to tile. Did not see the UFH detail so have not commented on it.

BAl is good product though quite expensive. May be worth checking in with a local tile company who may also be able to assist.

 

[Colour Republic]

You really want 10mm insulating tile backer boards as minimum if you are installing UFH. Of course the greater the depth of the insulating boards the more efficient and cost effective the UFH becomes. No insulation and the floor can take up to a few hours to become warm, a well insulated one can reach temp in 20 mins

 

[Qwerty]

I agree with colour republic.

 

[Tony73]

As above, and don't forget to back butter your tiles