Advice on tiling onto "overlay" underfloor heating

[Old Mod]

So this company has absolutely no idea what it’s talking about, or what the industry standard is for Tiling to ufh.
To me it sounds more like for timber floors.

The advice I would give would be two fold.
1. Ask to see test results.
2. Speak with the TTA, and get their recommendations on the method statement that you have been presented with, hopefully also being able to give the name of the person you have been dealing with too.
From the text in the pdf, it appears to be badly translated English at best.
Every tiler in here knows that floating floors should not be tiled to, and that the minimum ply wood overlay method would specify a minimum of 15mm as laid down in British standards BS5385
And it is certainly not industry standard to loose lay it! Haha

 

[Flintstone]

That’s an absolute embarrassment

 

[Spare Tool]

And we wonder why we end up making it up as we go along...

 

[LM]

Also another major concern is the ply being a fire hazard!
That has to be one of the most bizzare method statements I've ever seen, it's wrong on so many points.
The translation to english of such ridiculous advice is also terrible.
How can advice like this be allowed.
Lawyers would have a field day with this in the event of a claim.
@3_fall test results for the above would be very interesting indeed

 

[LM]

Adhesive and 'grout' layer???? what's that all about??

 

[One Day]

It seems pretty clear too that ALL ply available now is completely unsuitable for tiling onto.
Years ago it would bond really well to cement based adhesive, but every time I see or hear of ply underlay it has always failed to bond.
Crazy.

 

[Dumbo]

It seems pretty clear too that ALL ply available now is completely unsuitable for tiling onto.
Years ago it would bond really well to cement based adhesive, but every time I see or hear of ply underlay it has always failed to bond.
Crazy.

Does anybody know why that is . I think when they removed the carcinogenic stuff they removed the good stuff

 

[LM]

FG1 - Plywood (High Quality 5.5mm Flooring Grade Plywood) - http://fg1-plywood.co.uk/

This may be of interest to some of you and is being pushed a lot but for tiling there's better options in backer boards.

 

[John Benton]

Clearly no idea whatsoever!!! Looks like they've use Google translate from Swahili to Pigeon English. It makes no sense at all.

Perhaps the individual who created the sequence of materials diagram was indeed a 'retro git' him or herself!!!

 

[Jonner]

Firstly Many thanks; Marc, Andy, HM, ACT, Lee Mac, Impish, JCR & John for your time and comments, it really is greatly appreciated.

Following your feedback and my earlier discussion with Marc we are going to cancel the idea of an "overlay" underfloor heating system.
We in are in a lucky position to be installing the underfloor heating only on the ground floor in 2 rooms that connect to each other. Each room currently has a concrete floor. Please note the heating system is an Air Source Heat Pump with flow temperatures of about 35-40deg C.
So having done some more research we are now proposing to install underfloor heating with a screed, (either concrete or resin). We are then hoping to tile on the screed.
Do you think this would be the best approach and do you have and do's and dont's when considering this type of floor and tiling?
Any advice gratefully received. Thanks again for all your help so far.
Cheers Jon