Popped tile could it be the underfloor heating?

[Peter Woods]

Hi

Just a quick query re a tile that has popped. I want to rule something out before discussing it with the customer. I've laid some floor tiles on top of ply ( ply was of sufficient thickness and more in places to level up a floor over 100 years old) and electric underfloor heating laid. The appropriate primers, adhesives and additives etc have been complied with as well. Job was completed last summer.

There has been a small leak from a wall basin recently and this only revealed itself on the wall down downstairs and part of the ceiling. The customer is adamant that the tile has popped because of it. I dont' believe it has due to the fact that the water has mainly shown on the wall downstairs and I could see the drips falling along the wall and away not touching the ply. Even with what has been collected withing the ceiling I don't believe this would have affected the subfloor above given the thickness of the old boards as well as the ply and the underfloor heating that would appear to be constantly on!

Now, the customer has by her own admission reprogrammed the underfloor heating to make it even warmer. It is very warm to the touch. Has anyone had problems with underfloor heating that has been mis programmed in relation to the sub floor and tiles where it has affected the adhesive etc. I know it's a bit of a random question but I want to have everything covered before I start the repair and not only that, if there is a potential issue, she needs to be advised.


Thanks Pete

[grumpygrouter]

Not much experience along these lines I am afraid, only done 1 floor with UFH and that is still fine. My gut feeling is that if flexy adhesive has been used (a good one) then that should be adequate to absorb any movement between the 2 materials. It may well be that the leakage could have swollen the ply a bit. is it possible that the popping of the tile could be unrelated to either issue. maybe it was not quite fixed correctly - and please understand I am in no way being critical of your work - these things happen sometimes?

If it was the water, I would say that any costs incurred should not be your responsibility as your work was carried out in accordance with the appropriate standards.

Grumpy

[basshunter]

that water stuff can travel via capillary action to wherever it wants.Just a thought

[Leatherface]

Did you self level over the mat prior to fixing tiles ?
This is the best way to do it.
Trying to tile straight onto the mat leaves more chance of not getting a good bed of adhesive and air pockets. Tiles will be more likelt to lift and also the cable / mat should be 100% covered so as to ensure it does not over heat.

[tfs]

Hi Mate,

I know for a fact that most adhesives are not to be exposed to high temperatures. I know this from using adhesives for floor laying (Karndean etc0. This adhesive is ofcourse different but, I would amagine that tiling adhesives could only take so much heat especially if it may have been exposed to water or dampness.

Normally when you have a leak it can run along the floor joists and if bad enough can lead in to any other room on that floor. I think it could be possbile that the water was under that tile.

I think you should contact the manufacturer of the Adhesive you used and ask them if there is a limit as to which heat the adhesive should be exposed to.

Im not a qualified tiler yet but, I do have a bit of knowledge due to experience in the bulding industry so, this is what my opinion is based on.

regards

Kris

[Dave]

Originally Posted by tfs

Hi Mate,

I know for a fact that most adhesives are not to be exposed to high temperatures. I know this from using adhesives for floor laying (Karndean etc0. This adhesive is ofcourse different but, I would amagine that tiling adhesives could only take so much heat especially if it may have been exposed to water or dampness.

Normally when you have a leak it can run along the floor joists and if bad enough can lead in to any other room on that floor. I think it could be possbile that the water was under that tile.

I think you should contact the manufacturer of the Adhesive you used and ask them if there is a limit as to which heat the adhesive should be exposed to.

Im not a qualified tiler yet but, I do have a bit of knowledge due to experience in the bulding industry so, this is what my opinion is based on.

regards

Kris

Hi kris mate....

i can only comment on BAL adhesives as they are what i use most....BAL flexible adhesives will withstand temperatures from -30dg to +100dg.....
I would presume that most adhesives will follow suit to this standard....
hope this helps......

[tfs]

Cheers,

I think the exceeding that temp would perhaps burn down a house. lol

[Dan]

I have experience in tiling and underfloor heating fitting and selling and can comment but don't take my word for it.

When did the job get completed and when was the first switch-on of the underfloor heating?

If the customer has turned up the heating soon after it's been installed I'm guessing your floor hasn't cured properly and the whole setup (with it including so much wood) hasn't acclimatised to cope with the extra expansion / retraction due to the heating.

When you install heating on a concrete floor and use flexi gear you need to leave it a week or so before turning it on and then increase it by about a degree per day over the next couple of weeks when finally the customer can turn it off or up and use it as normal.

When you install heating on wood the same principle applied but you will find the floor will need more consistency with the heat. So if the customer programmed the stat to go off at night and come on full during the day for example the wood just hasn't expanded fully to get used to it's max heat. Therefor it's simply 'stretching' in places quicker than it's 'stretching' in other places.

With you saying some of the floor even had more ply on I'm guessing it's down to the fact that there are different thicknesses in various places? and the heating hasn't been 'broken-in' properly.

The water shouldn't have an effect because you should have used exterior grade ply and primed it, then using flex gear which has additives in it that also decrease the water absorption rates. That with the heating would soon dry up any dampness so to speak coming from any few drips - even over a 24 hour period.

Recap:

I don't think it's the water, I think it's the customer programming the heating too soon. Even if it was left 12 months you can't switch it on full and let it go off after 6 hours and then do it again and again over a few days.

How to investigate: pull up the loose tile, be careful not to snag the heating cable. If the adhesive has broken away from the wood, then the wood has expanded and retracted quicker than the adhesive - or visa versa. If the adhesive has broken away from the tile but is still stuck to the wood (that's an easier fix) but that's down to fixer error (which is the cause of more than 70% of failures in the UK - so I believe - figure may be wrong but it is a high one for sure).

How to go about it from here: you really need to investigate BEFORE suggesting what you think it is. If you go to the customer now and blame her she'll retaliate and wriggle out of the problem. You need to say you're doing a report for the adhesive rep and he wants it in writing. Then state on paper the date it was installed - what gear was used - confirm she has the instructions / guarantee for the heating (which will state the initial starting procedure - and the 1 degree increase per day rule) and then ask her which date she programmed the stat.

Once you have it in writing go away for a brew, come back and say you think it's down to the incorrect initial start-up.

Obviously after checking to make sure it really isn't fixer / material selection error.

THE FIX: If it's down to the heat up thing- sound the tiles, lift the bad ones (might be a maul so charge for your time!) re-fix them and LEAVE THE HEATING FOR 2 WEEKS THEN TURN IT ON - CHECK THE TEMPERATURE READING AND SET IT TO MANUAL AT THAT TEMPERATURE - THEN TELL MRS JONES TO KNOCK IT UP ONCE PER DAY USING THE UP ARROW AND AFTER SHE HITS 22 degrees or so she can turn it off. It is vital that the heating isn't turned off during this period too. Certainly while we're in our cold months!

Good luck and report back to base with your findings.

If you need help from me send me an email: info@tilersforums.co.uk and I'll do my best to explain better. I could even send you my phone number if you felt that would save you some head ache.

[Proper Job]

alright mate i a have some exprience with underfloor heating, i always use two part adhesive and never had any problems. The under floor heating should be turned up by 2 degrees every other day or 1 degree every day as stated per instructions until you reach the max setting and always say at least 7days after been laid before using.

[Peter Woods]

Hi chaps,

just logged in for the first time in 5 days, thanks for the advice, especially Dan. I back with the customer in a few days so I will update you in due course.

Pete

[Peter Woods]

Hi,

Currently in dispute with the customer and I haven't been able to examine the tile. Personally i hope it is the easiest option where the installation was poor under that particular tile!

I don't know where I stand legally commenting about an ongoing dispute/issue I'll be guided by the forum administrators I suppose.

Pete