A big flooring problem!

[hpandlou]

i have been following this thread with a huge amount of interest but havnt posted yet as I was completely stumped. The primer may well be the problem. I cant say that I have used any of unibonds range but if PVA was used this could well answer why the adhesive has come away from the scread.

I have found that some of the tilers with the 35yrs experience are the worst for keeping with the times, I worked for an old guy who had over 40yrs tiling under his belt and his tiling LOOKED lovely and customers loved him and recommended him. I worked with him for a couple of weeks and walked away because I knew that his tiles wouldnt last and it wasnt worth my reputation. He had no idea about the range of adhesives out there now adays and just as importantly primers.

If you do a search on here you will see why PVA is such a bad idea. I hope between us we can get this one cracked (forgive the punn).

Punn forgiven!
I have seen examples of this tiler's work - jobs that have been in-situ for a long time. He did work for a long time for a very well-respected company as a 'head tiler' and is still spoken of very highly by them. I know their 'practises and procedures' are bang up-to-date, and he follows them.
Perhaps naively, I do trust that he has done a good job, but something has gone wrong and until we can list a tile, we won't really know - none have yet 'popped up', so I need him to come back to do it. All the advice and thoughts I have had here have been fantastic and, at the very least, I feel I can talk to him as a little bit (a very little bit!) more of an expert - thank you!

 

[Ajax123]

Sounds like delamination rather than movement. Dural would generally deal with movement any way. The one question I can't seem to find the answer to in the whole thread is where the delamination has occurred. i.e. is it at the interface between the adhesive and the tile, the adhesive and the dural, the dural and the adhesive that is sticking it down, the dural adhesive and the screed or within the screed itself. Have any of the tiles been removed to look at what is going on underneath. You will not be able to answer this without taking up a couple of tiles to see where the failure has occurred.

You have eliminated moisture in the screed by no leaks in the UFH and by using Dural so I don't beleive moisture is the issue so in my mind that is dismissed.

You say the screed was "VERY good" - how do you define this - how do you know.

The length of time between comissioning the heating and the tiles going down could present a problem in terms of preparation - from my scan reading the posts it appears that this was 12 months ish. how was the screed treated/used during this time

These are some of the questions I would need answering before venturing any opinions.

Fibres in the screed do not add strength. The offer no improvement to either compressive or tensile strength of a screed or a concrete. They are used to offer a measure of resistance to the screed cracking due to shrinkage. The will not prevent the screed from moving or create stress within the screed.

 

[hpandlou]

Hi, I don't know the products used on your project (except for the Dita), so I can't hazard a guess about any of that. You mentioned that all the expansion joints were in placed...what is the layout and placement of these joints? Could you post a diagram that shows where they were placed? What type were used? How wide? How deep? All the way around the perimeter, too?

A progressive loosening of tiles like the way you have described can sometimes be because of the shearing action across the floor when an installation has insufficient room for expansion and especially if it has additional stresses on it from heating, sunlight, etc.

Hello! Perhaps my post wasn't clear re expansion joints: the room is approx 5metres by 4metres and there are expansion gaps around every edge, and around a support pillar at one point in the room. I've read re the requirements of 'man-made' expansion joints, but internet sites seem to suggest this is only necessary when there is a single, unbroken length over 10metres (?) The gaps around the edge of the room have never 'closed' or appeared to suggest there isn't sufficient room to expand - or do I have that completely wrong?
Thank you!

 

[Ajax123]

Punn forgiven!
I have seen examples of this tiler's work - jobs that have been in-situ for a long time. He did work for a long time for a very well-respected company as a 'head tiler' and is still spoken of very highly by them. I know their 'practises and procedures' are bang up-to-date, and he follows them.
Perhaps naively, I do trust that he has done a good job, but something has gone wrong and until we can list a tile, we won't really know - none have yet 'popped up', so I need him to come back to do it. All the advice and thoughts I have had here have been fantastic and, at the very least, I feel I can talk to him as a little bit (a very little bit!) more of an expert - thank you!

Trusting that someone has done a good job is very largely irrelevant. Something in the installation has been done incorrectly otherwise it would not have failed. It may very well not be something the tiler has done but you can really only say that he did a good job in relation to what you know about tiling. If you know enough about the various aspects of the project to determine when a good job has been done or not then I suspect that you would not be on the forum cos you would already have the answer. Sorry for appearing rude or condescending.

 

[Ajax123]

Hello! Perhaps my post wasn't clear re expansion joints: the room is approx 5metres by 4metres and there are expansion gaps around every edge, and around a support pillar at one point in the room. I've read re the requirements of 'man-made' expansion joints, but internet sites seem to suggest this is only necessary when there is a single, unbroken length over 10metres (?) The gaps around the edge of the room have never 'closed' or appeared to suggest there isn't sufficient room to expand - or do I have that completely wrong?
Thank you!

in a room 4mx5m forget expansion. Even with sand cement screeds this is well within the accepted bay sizes for this type of installation. The depth of screed at 65mm is also correct for a floating installation. My previous questions remain.

 

[hpandlou]

Sounds like delamination rather than movement. Dural would generally deal with movement any way. The one question I can't seem to find the answer to in the whole thread is where the delamination has occurred. i.e. is it at the interface between the adhesive and the tile, the adhesive and the dural, the dural and the adhesive that is sticking it down, the dural adhesive and the screed or within the screed itself. Have any of the tiles been removed to look at what is going on underneath. You will not be able to answer this without taking up a couple of tiles to see where the failure has occurred.

You have eliminated moisture in the screed by no leaks in the UFH and by using Dural so I don't beleive moisture is the issue so in my mind that is dismissed.

You say the screed was "VERY good" - how do you define this - how do you know.

The length of time between comissioning the heating and the tiles going down could present a problem in terms of preparation - from my scan reading the posts it appears that this was 12 months ish. how was the screed treated/used during this time

These are some of the questions I would need answering before venturing any opinions.

Fibres in the screed do not add strength. The offer no improvement to either compressive or tensile strength of a screed or a concrete. They are used to offer a measure of resistance to the screed cracking due to shrinkage. The will not prevent the screed from moving or create stress within the screed.

Thank you for your comments.
None of the tiles have yet been removed - although a lot are showing they're moving and there is extensive hairline grout cracking, none appear very easy to prise up. I want the tiler to be here when it is done, so that we can take photos as has been suggested and so we have him onboard from the beginning. He is aware of the problem - he was here last Friday - but it has got considerably worse in the last 3 days and he needs to come back.

To clarify: the screed was laid at the beginning of August; heating commissioned mid-September and then floor was covered in various rugs until tiles laid in mid-October.

I am no professional re screed - again, I can only trust the plasterer who has been with our job from the beginning and was, again, 'the man you need if you can afford him'! He is always booked up way in advance and I can only take that as testimony to his trade. He came back a number of times to look at the screed as it was drying/curing, knowing what was going on top, and was very happy with it. He came again this morning and he is coming back when tiler is here and tiles lifted.

As soon as I know where/if delamination has occurred, I will post!

Many thanks!

 

[Ajax123]

from your descriptions I suspect that the delamination has occurred at the interface between the Dural adhesive and the screed or within the screed surface itself - will be interesting to see my guess is any where near the mark.Will look forward to seeing the posts once the tile has been lifted. Some pics would be useful as well.

 

[hpandlou]

Thank you - very much appreciated.

 

[The D]

Tiler - highly recommended by a number of trades and shops as being 'the one you have to have' - came to lay the floor in mid-October. He was unhappy with the number of small hairline cracks in the surface of the screed and recommended we use 'Ditri

i think this may be screed related

 

[Ajax123]

Tiler - highly recommended by a number of trades and shops as being 'the one you have to have' - came to lay the floor in mid-October. He was unhappy with the number of small hairline cracks in the surface of the screed and recommended we use 'Ditri

i think this may be screed related

I have a gut feeling along the same lines but I am reserving judgement for now

 

[DHTiling]

Just to add the excellent info above... you say 10 mtrs in one run of tiled length.. this is only for unheated screeds.. you can literally half this with heated screeds but again the Dural should cope with thermal stress over just 5 mtrs in length.

 

[Scott]

Just out of interest what size grout joint have you got?

 

[kiwi Mark]

Will keep a close eye on this myself from what I have seen on my job so far without lifting a tile yet it appeared the problem was between the tile and mat, it looked as if ady had shrunk and dried up was able to pull out a couple of chunks under door threshold.No pva used on mine. Will keep you all up to date when tiles are lifted wont be till after next week tho.

 

[hillhead]

This is interesting for all of us who use ditra or dural, lets hope we all learn something here.
It could be anyone of a number of things. The chances of wrong primer being used could well be the problem.
Let's hope it's all clearer soon enough and it all ends well for the customer.

 

[cornish_crofter]

Will keep a close eye on this myself from what I have seen on my job so far without lifting a tile yet it appeared the problem was between the tile and mat, it looked as if ady had shrunk and dried up was able to pull out a couple of chunks under door threshold.No pva used on mine. Will keep you all up to date when tiles are lifted wont be till after next week tho.

Is it possible it could have been mixed with too much water?

Again, as far as the OPs problem is concerned, I do wonder whether the PVA could be the problem.

Very interesting thread to read.