Tiling over multiple floor levels and types

[Reallyme]

Hi all

 

I'm looking to tile a large part of my downstairs ideally without thresholds or level changes between the doorways and where the currently-different floor sections join. But, the sub floors are a mix of materials and levels right now. We have;

- About 30m2 of very new chipboard flooring that is about 10mm higher than the adjoining;

- 10m2 of old concrete+screed flooring, which itself is about 3mm higher than the adjoining;

- 23m2 of suspended timber flooring

 

So about 13mm height difference between highest and lowest subfloors with the concrete+screen section acting as a go-between

 

The tiles I'm planning to put down are 600x400 porcelain 

 

Do you guys have any recommendations with respect to dealing with the level and material changes?    

[markc]

Firstly need to look at the suspended timber floor … does it flex / bounce? If so then your tiles are going to crack and/or pick up on the corners.

assuming everything is solid you then need to get everything pretty level, especially at the floor change locations. Thin screed/levelling compound over a timber floor is going to break up so that’s out, really looking at plywood to bring levels up.

then probably a decoupling mat over the entire area  - others on here with much more tiling experience can/will be better able to comment on this.

Edited September 18, 2023 by markc

[Mr Punter]

If this is an old property with not much floor insulation the tiles are going to feel really cold.

[TonyT]

Rewiring/ re plumbing required prior to tiling required?

[nod]

2 hours ago, Reallyme said:

Hi all

 

I'm looking to tile a large part of my downstairs ideally without thresholds or level changes between the doorways and where the currently-different floor sections join. But, the sub floors are a mix of materials and levels right now. We have;

- About 30m2 of very new chipboard flooring that is about 10mm higher than the adjoining;

- 10m2 of old concrete+screed flooring, which itself is about 3mm higher than the adjoining;

- 23m2 of suspended timber flooring

 

So about 13mm height difference between highest and lowest subfloors with the concrete+screen section acting as a go-between

 

The tiles I'm planning to put down are 600x400 porcelain 

 

Do you guys have any recommendations with respect to dealing with the level and material changes?    

Yes 

You should always add a preformed expression joint I in every doorway 

I set these so that they can’t be seen when the door is closed It also allows you to change direction with the tiles 

Or material 

[Reallyme]

Thank you for the info guys - you gave me lots to look into

 

There isn't much movement in the suspended floor at the moment - just a couple boards that could do with tightening down.  Would ply used to bring the levels up also help provide any stiffness there too?

 

There is some rewiring and plumbing to be done yes, mostly under the suspended floor section - does that change things at all?

 

It sounds like my best bet would be;

- ply to bring the levels up

- self levelling compound the whole area, or, if things are pretty flat after the ply maybe just do self levelling compound in some areas & feather the edges?

- decoupling mat the whole area
- expansion joints in the door ways - how long of a tile run is ok without joints? 2 of the 3 doorways are well suited for them, but 1 doorway would break the brickbond pattern. Without a joint in that door way, the length of that tile run would be about 8.5m - is that too long without an expansion joint?