Marble Floor Tiles - Hairline Cracks

[Dan]

I'm sick of this now, we have all had issues with floors, I Know I have and this is after doing everything right.
Every bathroom I've done and I go back to do other jobs, my eyes are all over the floors checking for the hairline cracks. I recommend all floor tiles are porcelain now to my customers as Im sick of stressing, everytime my phone rings I'm paranoid I'm going to have to rip a floor up.

Granted I've only really had two fail over Hardiebacker joins and the second one is only one line.

Just having a general rant OP, I mean what forces are really at work to pull a tile apart? in the OP's case the ply shrinking?

I saw another floor recently done by a guy with a fantastic reputation who tiled a floor and the grout has huge long linear cracks through most of the joins so much so you can wiggle the grout out like a loose tooth.

You're kind of hiding the problem if you use porcelain. All the same stresses and deflection will still be there. You're just prolonging the problem. The tiles might pop off one day.

You're making the structure of the floor be the porcelain tiles. Which will help to a degree. But the floor should be structurally sound before the tile.

Love the rant though lol 😛 😛

 

[Bathfix Bob]

Can you live with the cracks Alkaz? theres no easy fix.

 

[Old Mod]

This is NOT a fix, it's a way to cover up the cracks, possibly.
If they're not too prominent you could colour match the marble with Akemi and actually repair the cracks and maybe pass them off as natural fissures, maybe!
No idea how long it would last, would depend entirely on floor movement and fitting technique used. Might be worth exploring if you don't want to rip it out.

 

[NZ_Tiler]

Following day we installed electric heating mat covered with mapei self-levelling compound

Was it mapei fibreplan you used over the floor?

How did you commission the UFH?

As above though, ply is to thin.

 

[Time's Ran Out]

Under floor heating, marble and no uncoupling membrane - just a disaster waiting to happen.

 

[Stef]

Why did you fit ply on top of tile backer boards?
Was tile backer boards glued & screwed to the subfloor?
Should have fitted 6mm ply then the backer boards, not ideal but would have given u more of a chance.
There should have been a decoupler fitted as soon as you introduced heat into the floor.

 

[Kevbos]

Everyone forgot to ask when heating was turned on .that is big problem if turned on too early after fixing tiles .firstly floor not strong enough .then weak tiles .but if you turn heating on too quick everything shrinks and tiles cracking suggests this .As they not lifting but cracking .3 to 4 weeks before heating goes on .then lowest setting 2 weeks then increase slowly .your tiles cracked because they are weakest point .think of the buckets of water that went into that floor .

 

[Alzak]

Hi All,

Many Thanks for replies appreciate support.

Heating was not switched on yet as I knew about giving some time for floor to settle before heat is introduced.

Reason for PLY above hardie was to add some extra strength, hardie was in 4 pieces (put using brick fashion) and PLY was in one piece thats why I thought it would be much better to install PLY above hardie... looks like this was my mistake oh well you live and learn,

I don't really want to rip this floor apart (definitely for now) so would try to live with those cracks, I noticed some of those cracks appeared in natural veins of the tiles and then spread across.

Worst thing is that I bought uncoupling membrane but decided against using it as floor is raised by about 40mm already (with tiles adhesive,self leveling, ply and hardie) so didn't wanted to add additional height...

Self leveling used is Mapei Ultraplan thickness around 6-10mm.

Back home we have electric heating(wet)and natural stone on ground floor in my parents house without any hardie boards or uncoupling membrane and it is fine for past 15 years or so... but looks like first floor wooden subfloor is probably not best option for stone without a proper preparation.

 

[Stef]

You say Mapei ultraplan was used, was it ultraplan Eco or renovation screed?

 

[Alzak]

It is renovation screed