Garage Conversion - what flooring to use for tiling onto?

[JonnyS]

Hi,

We're in the process of converting our garage into a kitchen/dining room. The back of the space was originally a separate utility room and we've knocked though. The floor in the garage has has a damproof course, insulation and joists. The utility room has a concrete floor.

I'm wondering what is the best product to lay on the joists in order to tile on top of the whole lot? I've read some things saying P5 chipboard/caberfloor is fine, whilst others saying you need to use 22mm marine ply wood. I also read something about needing to have an expansion joist between to concrete flooring at the back and the rest of the space.

Any help/advice would be much appreciated, thanks.

[wine~o]

What is on top of the joists at the moment ? are the 2 floors level with each other ?

[JonnyS]

Hi, thanks for your reply!

We have OSB board on the joists at the moment, but the joiner is coming in this week to lift them and drop the height of the joists, so when the board goes back down the height is level with the concrete floor at the back.
The joiner suggested putting caber floor/P5 chipboard down rather than putting the OSB board back down, suggesting that would be much better if you're going to tile on top.

[wine~o]

chipboard/ply is not the answer. (Your Carpenter might be very good but he's not a tiler... )

https://www.google.co.uk/search?q=tile+ ... e&ie=UTF-8

tile backer boards, various different makes/sizes / prices. I hope the link works...

[JonnyS]

thanks again, much appreciated!

So if I wad to use something like this?:
http://www.tilegiant.co.uk/no-more-ply- ... oards.html

or this:
https://www.jameshardie.co.uk/product/hardiebacker/

What do I put on the joists? As that wouldn't go straight onto the joists would it?

[wine~o]

Ahhh sorry, yes you'll need a chipboard or similar flooring under the tilebacker. so 18mm chipboard add 6 mm for the backerboard plus 3 / 5mm for tile adhesive plus the thickness of the floor tiles.

Nothing is ever as simple as it seems...

[JonnyS]

And would I need tile backer for the concrete section too? thanks again, really helpful!

[wine~o]

No need for backer board on concrete. are you doing the tiling yourself or using a tradesman ??

[JonnyS]

Ok great. thanks. I'm not sure yet. Once we've got the floor down, we wont be tiling for a while, but just want to make sure I don't bodge things up in the meantime of future plans.