Hello. I wonder if anyone can give me any clues as to what might be wrong with my floor.

in 2005 we had a new Amtico floor fitted in the kitchen and dining room. Our house was built about forty years ago and considerably extended about twenty years ago (before we bought it). The dining room is wholly within the extension, the kitchen was extended by about 50% so part is the original 40 year old floor. The floors are concrete throughout the house.

The floor in the dining room is perfect but in 2008 a bubble appeared under one of the tiles in the kitchen. Investigation by a plumber suggested that the dishwasher had been leaking. The affected tile was quite close to this area and we concluded that this was the cause. The tiles were taken up, the screed removed back to the concrete and a new floor laid on to three coats of latex screed (the floor was pretty uneven after the previous screed had been removed by a contractor with a pneumatic drill). Plenty of time was allowed for the floor to dry out and dehumidifier was used (although I'm not sure how wet it was - there were no visible signs of damp).

Last week we noticed that four of the new tiles are now 'bubbling up.' This is in a different part of the floor about three feet from the previous problem, still within the floor area of the extension though. Rather than air bubbles there appear to be 'lumps' under the tiles.

I wonder what might be causing this? Is it possible for moisture to pass through concrete (in which case why is the dining room unaffected?) Another suggestion is that there might be an old leaking pipe beneath the kitchen (but the plumber did not find any evidence of this). We will seek advice but I'm reluctant to have the floor dug up again when there may still not be a clear cut answer.

If anyone can suggest possibilities or has encountered similar problems with an Amtico floor laid on concrete I would very much welcome any suggestions. We haven't raised this with the installer yet.

It could be done to the glue used.. i am not up on Amtico but a member on here is.. Chris roe if i recall correct..

Is the screed coming away from the concrete? It usually shows up by several tiles moving up and down together. The screed is still intact within itself but has come away from the concrete.

I haven't lifted the tiles. I'm looking at several large uneven 'bubbles' that feel hard and cannot be pressed back even when I stand on them. May suggest that the screed is expanding. If moisture is causing this I'm at a loss as to where it is coming from. I think it is more than just the glue.

The new floor will expand at a different rate to the old one.. is the tile heaving at this intersection..?

A common problem I come across ( luxury vinyl tiles is my speciality) is screed being applied without a primer to the concrete. This is more common with thick or multi layers of screed. Basically the adhesion of the screed is limited and over time it breaks away as concrete expands & contracts. What you may have a slab of screed gradually floating on the concrete rather than sticking to it. Usually this doesn't appear for a considerable time after being applied say 18 months or so onwards. Most screeds for vinyl tiles are limited to thickness ( usually 10mm) and shouldn't be thicker unless an aggregate is added. The sure way to check for this is to lift a tile and hit the screed with a hammer. If the screed is sound no harm done but if it is lifting from the concrete it will crack. The initial effect is usually a lump appearing in the floor say 2 to 5 feet in diameter.

Initially I would bring in the dealer/installer and get them to examine it. If you're not happy with their reaction I would contact Amtico who will send a rep to evaluate it. If my suspicions are correct it may be a case of a full replacement but it needs to be fully checked.

Just remember the hammer test.

How hard do you hit it.........

Originally Posted by Ajax123

How hard do you hit it.........

A reasonable hit should do it. Remember if a screed is sound the worse that will happen is a slight dent which is easily repaired. If it cracks there's a bigger problem. Although if the screed has boken away you can usually tell by the sound from tapping it...maybe should have mentioned that first.

Thanks for all the suggestions. You may be right SandyFloor. I'm pretty sure there was no primer and the screed was very thick - three coats were needed. What I have is several lumps appearing but they are close together and may well be connected. Floor was laid two years ago.

I have read enough here to understand that the process of preparing a substrate is not a straightforward as it might appear. I suspect this may take a while to sort out...

Good luck and please come back and let us/me know how you get on. Did you get the floor supplied and fitted from a dealer?

Yes it was a local dealer. Small reputable company. We have been customers for years so I think they will play fair.

Having just looked at the Amtico warranty on their website I'm not sure how interested they would be. It says this only applies to fading/wear and tear, not to other defects unless notified in the first six months, and only if you filled in the registration card.

I will let you know how it pans out.

The Amtico gaurantee is a product gaurantee and this sounds like an installation problem. It's probably a good thing you went through a dealer as they're more likely to be helpful as opposed to a fitter installing goods you purchased yourself.

Screeds over 50 mm dont have to be bonded to the substrate, at least in my regs,They act like a floating floor.
anyways get a moisture meter and check the screed.
report back with your findings.

Trev

It could be 2 things in my experience. Either the substrate was not prepared properly and if the screed is not bonded to the concrete with a bonding agent then a poloythene memebrane should have been laid between the concrete and the screed as an unbonded screed.

A floating sand cement screed is laid on insulation which the minimum depth is 65mm.

If this was done then it could be that the tiles were laid whilst the screed was not dry and now the moisture is trying to escape which would cause the tiles to 'pop'. A standard sand cement screed at 75mm takes 110 days to dry.

Hope this is helpful.

Let us know how you get on.