Just checking how much height I'll need

[Rod Evans]

Hello all,

Can you please advise what the minimum finished height I need to plan for if I want to put down a 10mm Ceramic tile onto existing joists.

My plan was to put down 18mm T&G...then a tile backer board (thickness?), then adhesive (thickness ?)....then the tile.

My perfect world is not more than 40mm in total...is this possible?

Cheers

 

[Bond]

40mm is about bang-on.

 

[Spare Tool]

Just about spot on 40mm with a 6mm Hardibacker plus 2mm adhesive, plus 10mm tile with a 4-5mm compressed bed

 

[Rod Evans]

Thanks Bond.

How does it add up in terms of the different layers?

I just saw a post recommending the use of 19mm or 22mm Hardie backer board straight onto the joists then tile straight to it....which would be great if it works....

 

[Rod Evans]

Thanks..

What is a compressed bed?

 

[Spare Tool]

If you use a 10mm notch trowel to lay your tiles by the time you've bedded them in will compress down to 4 or 5 mm

 

[Rod Evans]

Understood...

I didn't mention that this floor would sit onto a wet UFH system which I'm putting between joists.

My guess is that the something like a 22mm Hardie backer board may offer a better / faster heat transfer medium rather than 18mm ply then 6mm tile backer....is that right?

 

[Spare Tool]

Well it would but you can't get 22mm hardi anymore.. Look up Knauf brio boards and ditch the ply

 

[Rod Evans]

Sorry for the delay...

So, I can use KNAUF Brio 22mm direct to joists over wet UFH and screw them down.
Then lay 10mm tiles on to the board and allow for 4mm of adhesive...making 36mm in total above the joists...is that correct and the best way?

Or is 18mm T&G Ply + 6mm tile backer + 4mm adhesive +10mm tile...making 38mm better?

All info gratefully received!

 

[Dumbo]

You will get a much better heat transfer through the brio board

 

[Cranbrook]

Understood...

I didn't mention that this floor would sit onto a wet UFH system which I'm putting between joists.

My guess is that the something like a 22mm Hardie backer board may offer a better / faster heat transfer medium rather than 18mm ply then 6mm tile backer....is that right?

For my own interest, how does this wet UFH between the joists work? Might want to do this in an upcoming new build so would be interested to know

 

[Rod Evans]

Thanks jcr ...is Brio board best screwed down to joists?

Can I get it from most tile merchants or is it better from builders merchants?

 

[Rod Evans]

For my own interest, how does this wet UFH between the joists work? Might want to do this in an upcoming new build so would be interested to know

Hi Cranbrook

I'm inserting 70mm of celotex onto thin supports between joists... then laying 25mm of pre routed UFH insulation panels with a spreader plate directly onto the celotex and also between the joists.

The spreader plates have flanges either side that just sit over the top of the joists and are fixed down to the joists so the entire sandwich of celotex / UFH / spreader plates sits between the joists ...then I'll lay my sub floor up of 18mm T&G structural ply with 6mm Ply base layer and a Karndean LET.. easy..!