Who’s at fault for this hairline cracking?

[On one]

The hardie hasn't been scrimmed also

As maybe......but I would have should the mesh on the UFH might have helped......but obviously not enough

 

[Simon Dale]

Might have to resume tomorrow its not facebook

 

[JohnsonL]

Is it just 1 crack going in one direction or multiple cracks going in mutiple directions?

Both directions

 

[JohnsonL]

The hardie hasn't been scrimmed also

He did actually scrim the backerboard, pictures show remains of it from where I’ve uplifted part of the tile to expose chipboard.

Although he didn’t Bed scrim tape into adhesive and then cover over, just stuck in over the joint.

 

[On one]

As it is a new build......shrinkage or excessive movement or joist problems?

 

[Dumbo]

As it is a new build......shrinkage or excessive movement or joist problems?

Probably all 3

 

[JohnsonL]

As it is a new build......shrinkage or excessive movement or joist problems?

Yeah but it’s not just that one joist/ area that would of moved. The whole floor all would of moved abit. The issue with this area is his hardy backer join directly inline and ontop of the chipboard joint. So a very weak spot which has failed at first but of movement.

 

[One Day]

I've not read all the replies so apologies if I'm copying anyone!

First - new build? Settlement/movement.
Second - Hardibacker joints line up with the floor boards (crazy thing to do!)
Thirdly - Hardibacker joints are not taped (which would have helped but probably not have prevented this)
Fourthly - Should have used an uncoupling membrane. In this situation I think Ditra would have saved you. An anti-fracture mat might have, but with a new build I would always insist on Ditra due to the risk of excessive movement - as you have here.

Who is to blame? Ultimately - the tiler as usual.

 

[JohnsonL]

I've not read all the replies so apologies if I'm copying anyone!

First - new build? Settlement/movement.
Second - Hardibacker joints line up with the floor boards (crazy thing to do!)
Thirdly - Hardibacker joints are not taped (which would have helped but probably not have prevented this)
Fourthly - Should have used an uncoupling membrane. In this situation I think Ditra would have saved you. An anti-fracture mat might have, but with a new build I would always insist on Ditra due to the risk of excessive movement - as you have here.

Who is to blame? Ultimately - the tiler as usual.

Yeah simple changes would of saved the whole job for the guy. But still it will be a nice job for me to put right.

 

[LM]

The defects are obvious. Incorrect layout of over board, no uncoupling and even the eufh isn’t incased in leveller. This job is a perfect example of the uses for fibre levellers and Ditra.

 

[HardieBacker]

Looks to be install error from what I can see and have read.

New builds are terrible for movement so belt and braces is always the best option.

Contact me if I can help in anyway