Tiles coming up, cracks, and hollow points

[On one]

Judging by how easily the tile adhesive is coming up off the floor,there was no or little priming

 

[DazedConfused]

Solid bed is near if not 100% coverage of adhesive between tile and substrate. It needs to be of a sufficient depth depending on tile and state of substrate. In your case you would want a 20mm x 10. Round notched trowel with a back skin to the time to ensure 100%

Given the tiles they took up had less than 50% coverage, if the rest of the tiles have similarly insufficient coverage would this be considered a defect to be rectified even on the tiles that show not visible signs of impairment?

Would I be wrong to presume the probability of the tiles having future issues due to insufficient adhesive coverage is much higher than it should be?

 

[White Room]

4/trade is Travis, not the finest in my opinion .

 

[acaciaguy]

If you have issues with some. You may have issues with all. I would pick 5 tiles at random across the area and take the them up. If. They are as others then the whole lot of the same. Sorry

 

[One Day]

The adhesive is made by Bostik and sold by Travis Perkins.
Although it claims to be flexible, perhaps it isn't flexible enough?

This other adhesive claims C2FT
4TRADE Flexible Non-slip Fast Set Floor & Wall Tile Adhesive White 20kg | Travis Perkins - https://www.travisperkins.co.uk/4TRADE-Flexible-Non-slip-Fast-Set-Floor+Wall-Tile-Adhesive-White-20kg/p/106850
whereas yours doesn't - and that would concern me greatly.
Unfortunately, there is no other data I can find...
Even if the adhesive is wrong, the installation method is so rubbish, it would likely have failed anyway.

 

[DazedConfused]

I would add though, that picture number 2 appears to show a crust stuck to the ribs under the tiles.
Could this be a layer of laitence which is debonded from the main screed? You can get laitence on any screed, not just anhydrite.

this is not good I take it?

 

[acaciaguy]

No. It’s a layer on top of screed like a scum which occurs when screed drys. It needs removing as the adhesive can’t bond soundly to it. It’s also possible that no primer was used.

 

[DazedConfused]

The adhesive is made by Bostik and sold by Travis Perkins.
Although it claims to be flexible, perhaps it isn't flexible enough?

Even if the adhesive is wrong, the installation method is so rubbish, it would likely have failed anyway.

On the back of the adhesive it has C2F on it. Should that be good enough?

 

[One Day]

On the back of the adhesive it has C2F on it. Should that be good enough?

Should be...

 

[acaciaguy]

That means it’s a (C) cementitious, (2) improved adhesive that is (F) fast setting

I have no experience of that brand. However the overall method and prep means (I so Would suggest) that any c2f addy would not help. It’s the not the adhesive at fault for the whole issue

 

[One Day]

I think we all know that it's a rubbish adhesive though, and if we tested it ourselves I would be amazed if it actually delivered.
Still, I think any adhesive would have struggled to stick given that there was so much air between the tiles and the substrate!

 

[DazedConfused]

If you have issues with some. You may have issues with all. I would pick 5 tiles at random across the area and take the them up. If. They are as others then the whole lot of the same. Sorry

can I insist they redo the tiles or would these incorrectly laid tiles not be considered a defect until they actually crack?

 

[acaciaguy]

My opinion would he rip up and start again. See if you can clean and save tiles. Sorry.

 

[acaciaguy]

can I insist they redo the tiles or would these incorrectly laid tiles not be considered a defect until they actually crack?

The method of fixing is defective. Not the tiles. You paid to have then fixed. The product is sound.

 

[Boggs]

I always thought you needed S1 adhesive for underfloor heating.
Could be wrong though.