Kitchen Floor Prep Recommendations! - Tile Advice

[Lakey]

Folks
This may not be the right Forum to post this on but I'm sure some of you will be knowledgeable in this field?!
I have been asked to prep a kitchen prior to installation of some fancy units etc.

The floor tiles tiles are 600 x 900 x 15 polished limestone so my first question is will 4" grinder or Sigma touch these?

Secondly & most importantly is the floor prep!
The current floor 'make up' is as follows

• 20mm Quarry tiles
• 70 sand/cement (or poss concrete)
• DPM
• Compacted earth!

The building is circa 1540's which explains a lot!
Anyway the customer is also wanting UFH but can't afford to raise the floor height.
What would you recommend?
My thoughts are as follows.

• 15mm Tile
• 3mm Adhesive
• 35mm Liquid screed (encapsulating UFH)
• Polythene
• 35mm Celotex
• DPM

Any advice/recommendations would be awesome....thank you!

 

[Bill]

What height constraints do you have if you just remove the quarries, laid a 6 to 10mm insulation board - 6mm screed which would hold Electric UFH, a 2mm decoupler the 15mm stone pus around 3mm of adhesive bed?

 

[Lakey]

Being an old building there are beams etc which would have an affect on the kitchen install.

Long story short, they went through the design process and order for an expensive kitchen only to then be told, 'By the way we only install the new kitchen, we don't do any plumbing, electrics, tiling or decs'!

I'm also conscious that they will need as much insulation as poss under the UFH to make it as efficient as possible as it will be their main heat source in the kitchen. It also needs to be water as it will be on a lot!

 

[Bill]

Electric or water can be used in the same way for heating - it all depends on the output.

Also, I hate customers that want palatial stuff but do not understand the costings, including the labour for skilled tradesfolk.

 

[Lakey]

They do understand that it will cost however it was not made clear by the kitchen Co. that the preparatory work wasn't included in the price. I understand the variety of UFH methods however also understand that electric UFH is v expensive to run especially on such a large area.

 

[Bill]

Read this.... depending on the size of the room, you may be better off with rads if cost is an issue.

https://www.uswitch.com/gas-electricity/guides/underfloor-heating/

 

[Lakey]

I'm not sure that cost is the issue tbh, I think it is more getting the floor 'make up' and process right!

 

[Bill]

Oh, and electric is cheaper to buy than gas and the installation of electric is cheaper too - all factors you need to facilitate.

 

[Bill]

The problem with your method above is the fact that it may be a potential floating floor which many tilers will not try to lay on, especially with ufh and stone.

 

[Lakey]

Really? That's like saying a 50mm sand/cement screed is a floating floor?

 

[Bill]

Really? That's like saying a 50mm sand/cement screed is a floating floor?

no - it is the insulation (celotex) that becomes floating

 

[Lakey]

A standard floor construction is oversite, celotex, screed so what is the difference in my proposal?

 

[Tile Shop]

Awwww...... I love a grey area.

Say "Floating floor" to 1000 people, 999 of them would immediately think timber or boarding loose laid on insulation. This is exactly what adhesive manufacturers class as a floating floor.

Not to be confused with a screed of the correct thickness on top of insulation, which although is technically floating as Tom says, is actually treated from a tiling perspective, as an unbonded screed and is hardly any different to any other unbonded screed laid on top of, for example, a polythene DPM. Isn't pipes on insulation covered in cement how most water-fed heated screeds are built?

At the end of the day you are just tiling onto screeded floor, and what the screed is laid on to, providing the screed is of the correct thickness (if it isn't it shouldn't be tiled) rarely comes into the equation so can be tiled as if it was just a regular sand:cement or anhydrite screed, bonded or unbonded, without issue. With heating, flexible adhesive is a must and decouple can be considered.

 

[Dumbo]

I don't know and I see where Tom is coming from . Yes you are right about what you say about standard floor construction and in my own house I have block and beam ,dpm, celotex, polythene slip coat , water ufh followed by alpha hemihydrate although a bit thicker than you are saying . @Ajax123 is the man for this as to wether it is ok .

 

[Lakey]

Well i'm pretty sure liquid screed is fine at 30-35mm
@Ajax123 what do you think?