Porcelain floor tiles - fitting question

[SteveM46]

My builder has fitted porcelain floor tiles in my new kitchen, two sizes - one 13" square and one 19" square - in a repeating pattern. We have just noticed that a few of the tiles - mainly larger ones - sound slighty hollow in places, as if there are cavities underneath rather than a complete layer of grout.

I'm not too bothered about this from the point of view of the sound, but I'm concerned that this may make those tiles in particular more susceptible to cracking in the future. Is this a reasonable concern, or am I worrying unnecessarily?

Thanks all.

[Chris77]

How have they been fitted? has he used a serrated trowel or has he dot and dabbed? If dot and dabb then chances are they will crack! usually if they are laid correctly with a serrater then you get 90 - 95% coverage of adhesive, but it is possible to get some small air pockets.

Whats the sub floor if its wood could just be the echo sound that you are not used to?

Edited by Chris77 on Thursday 1st September 10:06

[SteveM46]

Chris77 said:

How have they been fitted? has he used a serrated trowel or has he dot and dabbed? If dot and dabb then chances are they will crack!

Whats the sub floor if its wood could just be the echo sound that you are not used to?

I don't know how they were fitted. Most of them sound solid, it's just a few that are echoing. The subfloor is concrete, and we had similar tiles before so we are used to the sound.

[Chris77]

You should be ok, If you are worried then get the fitter back, so he is aware of the situation. If its just a few tiles he may re-lay them for you.

[SteveM46]

Chris77 said:

You should be ok, If you are worried then get the fitter back, so he is aware of the situation. If its just a few tiles he may re-lay them for you.

Hi Chris. I just went out and had a chat with him since he's back on site this morning. He says he has put 9 dabs under each tile, but because the original floor wasn't completely level, some of the dabs have flattened out more under the tiles than others.

So I think we'll be ok, but i will hang on to some spare tiles, just in case.

Thanks for the help!

[jas xjr]

If the floor was not level then he should have levelled it surely ? Hope it works out ok

[croakey]

Would of thought that if the floor wasnt level it would have been latex/self leveled prior to fit, also dot and dab in my experience doesnt work particularly well on large format floor tiles.

Being porcelain however you should be ok, theyre very strong!

[SteveM46]

jas xjr said:

If the floor was not level then he should have levelled it surely ? Hope it works out ok

The tiles and floor are very level. We've had an extension, so I think the variation is between the old floor and the new floor, since they didn't dig out the old floor and then re-concrete it at the same time as the new floor. I'm not sure if that's what they should have done, but as long as the tiles aren't likely to crack under normal use then I'm happy with the outcome.