Bathroom floor problem in new build house - please advise!

[flashtech]

Hello,

Would really appreciate any help.

I moved in to a new build house about a year ago. Recently, I could feel the bathroom floor cracking under my feet, so I pulled back the vinyl to examine the floor underneath (3 very short video clips):

1: http://tinypic.com/r/k975uf/8
2: http://tinypic.com/r/flgfwk/8
3: http://tinypic.com/r/2jcyh3t/8

I am absolutely no expert, but am I right in saying that the white bottom layer is the actual concrete floor, and the grey stuff that's breaking off is called screed? (the vinyl covering/finishing lay directly on top of the grey stuff that's breaking up, as shown in this diagram which seems to be the same as my floor, although I don't appear to have any "bonding" layer).

I reported the problem to the builders who investigated and said that what is breaking is called "latex", not "screed", but everything I can find online suggests that they're wrong, such as the diagram above.

The house builders didn't fit the vinyl themselves on top of the finished floor. I took this photo when the build was finished, when I was choosing what vinyl to buy from a local carpet shop - http://i59.tinypic.com/2vb38gn.jpg - you can see the finished floor (the top layer you see is what is now cracking) and the local carpet shop simply lay the vinyl on the top when I moved in. The builders are saying that because the vinyl wasn't fitted by them, they are not responsible for the cracking floor, and they're refusing to have anything to do with it - but surely the problem is nothing to do with the vinyl, it's the floor underneath that they built that's breaking up! Interestingly, the exact same thing is happening in my neighbour's house on the same development, which surely proves that the build quality was shoddy.

Surely I'm right and it's the builders' responsibility to correct their badly built floor?

Thanks a lot for your help.

 

[Hugh Jaleak]

Your builders are right, (on one count anyway!), the layer breaking up is actually a self levelling floor compound. Mixed to a very wet consistency, is is poured over an uneven floor and finds it own level before setting to leave a nice flat finish. Some types contain latex. It shouldn't however break up like that, it doesn't appear to have cured correctly and/or stuck to the surface underneath.

Screed is a very dry mix of sharp sand and portland cement, and laid to a lot thicker depth. The art of floor screeding is to get it level and smooth so to provide the finished surface for the occupiers choice of floorcovering. Use of self levelling compound in a new build would indicate a cover up of shoddy floor screeding, and the Builder's problem IMHO.

 

[ree]

Perhaps post this in the flooring forum?

I agree with the above. There are a number of variables to consider when using SLC over a slab, esp a new slab. We always prime before pouring SLC but as above how come you dont have a near polished concrete surface?

Only a guess, but my first thoughts are that the slab was green (still setting) when the SLC was poured?
Or, only a guess again, the subbies used excessive water (when they should have used expensive Latex "milk") in the SLC?

 

[flashtech]

Thank you both so much for your really helpful input.

At least I now know that the builders were right in saying the the bottom layer is the screed - but that's about the only thing they were right about!

The screed definitely feels rough and uneven when you run your hands over it, and it leaves a sort of chalky type powdery substance on your fingers. It certainly hasn't been polished and the SLC isn't even sitting on it or attached to it in any way - it's sort of "floating" above it as you can see easily in video 2.

Use of self levelling compound in a new build would indicate a cover up of shoddy floor screeding, and the Builder's problem IMHO.

Yes, it certainly seems like that's the case. It's so frustrating that the builder is saying that it's nothing to do with them because I bought my own vinyl - it's even more obvious now that the problem is due to their mistakes during the build, before the vinyl was even thought of.

Many thanks again for your help!