cracked travertine

[ms.tiles]

Hi All

Ive got a really nice job ive been recommended for, 77 sq mtrs of travertine.

The customers father has had a shop install about 120 sq mtrs in his house through the ground floor. 60x60 tiles with a high gloss finish(thats another tread coming im afraid). there are some long runs with a grout line cut through the door ways. The tiles seem solid,not dot and dabbed or anything but there is cracks running through the tiles in runs some 3 mtrs long and then going off in another direction, these are all over the floor in all different rooms. i went to see it today as the customer is worried his floor will do the same, i said i would be devastated if my worked cracked like that.
There is underfloor heating (water system) and im wondering if this was turned on to quickly but he said its been down 3 years and the cracks are getting worse, im now thinking the floor has failed. i did notice a crack all along the edge where the doors are to the garden and some skirting board looked like it was coming away.
Would this be movement in the screed or something more serious, i dont believe the tilers are at fault as tapping the tiles they seem solid and even along the cracks they dont sound blown or hollow.

I said id ask on here for any info as he said they might want me to replace some of the tiles, i wouldnt like to do the work as the shop has sent back tilers to replace a couple of tiles in a door way and they have cracked already,only weeks old.

Any info would be appreciated

Thanks
Mark

MS.Tiles

 

[White Room]

What type of floor is it, screed etc....

 

[ms.tiles]

hi
as far as im aware its a cement screed over water underfloor heating. the floor feels solid to walk on.

 

[Gazzer]

No decoupling membrane ?

 

[Rizzle from the Portizzle]

are the cracks in straight lines turning at 90 degres

 

[ms.tiles]

to be honest i dont know, it was done 3 years ago and my customers father wasnt there.
The shop sent people back a few weeks ago to dig up a couple of tiles and replace them so would it not be possible to do this with a dura matting or similar down.
The tiles are not loose along the cracks.

Im sorry i dont have to much info but with no matting and a standard screed on top of underfloor heating,cracks everywhere,could it be the screed.
Without all the info i know its only speculation on what it could be but atleast its something i can go back with and come up with a plan,even if its digging up a cracked tile to look at the floor below.

 

[ms.tiles]

no cracks are going all different ways some curving some straight lines some joining up and going off in another direction

 

[White Room]

Depends also how thick the screed is...

 

[Rizzle from the Portizzle]

sounds to me like the screed has sunk and is pulling a part you wil have to chop up a line of tiles and a patch of the screed to see if it surported under neath get a bucket of water tip in hole see if it flows a way quikly or the sceed holds it good luck

 

[ms.tiles]

ok
i dont think i can get these answers for you and it might not be worth the time replacing the tiles if they are going to crack again.
when i meet up with the customer next time i'll ask if he can get any info on the screed etc and then maybe come back to this thread.
With regards to the actual job im going to do,would it be best to use a decoupling membrane,its 77 mtrs through 4 different rooms and a basement floor all with underfloor heating,probably 70mm selotex then 50mm screed. how much of a difference does it make. i did something similar 2 years ago with 60x60 porcelain and didnt use one,went back last week to have a look and its exactly how i left it.

 

[White Room]

I think the screed should be a minimum 65mm with fibres....

 

[DHTiling]

Any expansion joints installed.?

 

[Discount Tile Supplies]

Any expansion joints installed.?

If theres movement in the floor and no expansion joints this will cause loads of problems. Has the grout crack and crumbled out. Best way is to crack a few tiles up and have a good look. Water heated floors are good there must be loads of expansion in the substrate. Post some pics?
Get good advice from a reputable adhesive manufacture (if theres one out there lol) and follow what they say then any probs go back to them.

Oh and travertine comes in all types of quality and its not the strongest product in the word. :yikes:

 

[ms.tiles]

Hi
grout looks fine,no crumbling out and doesn't looked cracked anywhere.
There is cuts through every door way which have been grouted.
The new job to do doesn't have any expansion joints cut in the screed. the screed depth was just a guess from me. i can get info when i next speak to the plumber and find out if its been turned on or not yet.
Many thanks

 

[jay]

Might be wrong but is this on a timber floor with heating then a screed on top

 

[ms.tiles]

Hi
to be honest i don't know. if it was wood then heating then screed what could be the cause.
Could it be the house has just settled and created all the cracks,it's a new build about 4-5years old. although the cracking has got worse over the last year

 

[jay]

You need to find out more info on the substrate and what has been done was it commissioned right pics might help try a straight edge on the floor is it falling away in areas

 

[widler]

trav on wet UFH is not the best in the world,the SLIGHTEST movement and they will crack,no expansion joint flexi addy or decoupler will prevent this

 

[bugs183]

Uncoulpling membranes do work, and are good for peace of mind. I've fixed loads of floors without them and had no problems (luckily!), but now it is common practice with good tilers to at least suggest to the customer that at a membrane is needed, balls in the customers court then. ways
Use an uncoupling membrane on the new floor, especially on an area of that size and with various door, these add stress points, expansion joints can be tricky because of the UFH, but certainly leave an ungrouted gap (10mm) between the tiles and the walls.
If the cracks in the tiles are in lines, then it's the screed thats moved or moving. Travertine is very unlikely to crack a screed.

 

[ms.tiles]

Hi All

I dont think there is a decoupling membrane under the tiles. There is 2-3mm grout gap cut through the tiles in every door way. i have photos but cant upload them as it says they are to large.

 

[Ajax123]

sounds to me like the screed has sunk and is pulling a part you wil have to chop up a line of tiles and a patch of the screed to see if it surported under neath get a bucket of water tip in hole see if it flows a way quikly or the sceed holds it good luck

Hmm interesting test. What will it hope to demonstrate??

 

[ms.tiles]

 

[jay]

Thanks for the pics have you worked out the substrate yet

 

[ms.tiles]

The tiles by the door,with the foot in the photo was only replaced a few weeks ago. the first photo,i know its not clear but has a crack running just in front of the top grout line all along the tile about an inch inside the edge of the tile

 

[Ajax123]

Hi
to be honest i don't know. if it was wood then heating then screed what could be the cause.
Could it be the house has just settled and created all the cracks,it's a new build about 4-5years old. although the cracking has got worse over the last year

That is probably quite a key peice of info. I suspect it is the shrinkage and movement associated with the screed. Up to a couple of years ago in the time frame we have had relatively mild winters but the last couple and most particularly last year we have had much colder. This would necesitate turning the heating up to compensate. This would encourage additional movement and possibly cracking of the screed due to thermal issues. An uncoupling membrane was probably essential in this installation as it would have helped alleviate the lateral stress created by the shrinkage.

One other question, if you place a straight edge over one of the cracks at right angles to the line of the crack is there noticable deviation across the crack. This would indicate some curling which is also a function of cement screeds.

I personally think thetimber bit is a red herring but i am willing to be proved wrong.