Advice please- adhesive under crack matting, how important?

[Bee-sadie]

We have wet underfloor heating and a screed down on our new kitchen floor. We bought crack matting after reading up to put down under or limestone tiles. Research said we needed to use full screed of flexible adhesive and then the crack matting, then adhesive and the tile. The tiler has then started doing it like this but then stopped for some reason. Meaning few rows of tiles have no adhesive under the matting at all and some has patchy screed, only discovered as few tiles were loose with just dabs of ahesive. The kitchen isabout 45 square meters andwe don’t know if we need toask him to take it up and relay at own cost? Or justtake up few rows that it’s missing from, and if that would weaken the soundones? Not all tiles loose but can see from few that arethat nothing under matting.We given him £1000 for materials and if need tocome up then wasted. Help!

 

[Waluigi]

We need pics please. Very difficult to advise without images. Initial thoughts are that it doesn’t sound promising

 

[Time's Ran Out]

If the mat is not stuck down to the screed it’s just floating.
Tiles will crack over time and as you’ve found will become loose.
What type of screed was put down over your wet under floor heating and how long ago was it done.
As above - doesn’t sound promising!!

 

[One Day]

...few tiles were loose with just dabs of adhesive...

I'm afraid this bit really tells us all we need to know.
Pics would help now, but don't let him continue...

 

[Old Mod]

Depending on how long the matting has been down, it could have been stuck down, but now free.
Two reasons why,
1. Adhesive was too dry when mat was put down, it has to be wetter than normal to penetrate the underside of the mat.
2. It can take up to 7 days before the mat is truly adhered to the mat, before this it can be very easy to free the mat inadvertently, especially if tiles are laid pulled up to adjust them, and re-laid again.
If his methods are incorrect, then he should be correcting them free of charge.
The under floor heating is turned off, yes?

 

[Middlesex Tiles]

£1000 for materials . . . I think he'll have enough cash left over to replace.

 

[Bee-sadie]

This was sent first day, husband was with him when this done.

 

[Bee-sadie]

This is from day two and the rows we concerned about. Feel he done nice job laying and cutting tiles in my inexperience? But this where few tiles have been lifted and nothing under the matting?

 

[Spare Tool]

£1000 for materials . . . I think he'll have enough cash left over to replace.

Don't think he's far off there, don't forget matting and adhesive for that, slc if needed, sealer, it all adds up, I'm just on with a very similar size marble floor and my quote for materials was only £50 less than that..

 

[Old Mod]

It’s exceptionally clean that’s for sure.
Can we see beneath the loose tiles?
So the matting is actually loose laid, no adhesive at all?
Also in the first day picture, the edge of the mat looks devoid of adhesive overspill.
I’ve never managed that!
Well not unless it’s stopped very short of edge.
Once pressed in, adhesive should leach from the edge, to show you it’s fully covered.

 

[bsc ceramics]

I agree with @3_fall on the 1st pic no ady squeezing between the two
rows of mat and the leading edge defo has none under it. O dear!!

 

[WetSaw]

Definitely loose laid the mat. Look at the doorway on day 2 and the curl on the edge of the mat on day one. As others have said, especially Mr Clean ( 3_fall) , there's always a bit of adhesive that squeezes out.