Hi

First post, brought on by problem with grout that my tiler can't work out.

We had smalto murano glass tiles laid into a bathtub. The "tub" was made up of a plywood frame and a fibreglass moulding underneath to waterproof it. Tiler used grey grout (called Omibond I think, a Dutch brand which we actually had supplied to us for the wall tiles, which were glazed zelliges from emery & cie).

The grout is now turning white in certain areas, and is getting worse by the day. There is no whiteness on the tiles themselves - only the grout. Any ideas as to what's causing this and more importantly how it could be resolved? Thansk in advance

Johnny

Ho johnny and welcome...Do you live in a hard water are..?,,this could be your problemm.( lime deposits)

can the bleach in cleaning problems not cause this in certain cases!

Dave I live in Scotland. I don't think that's it's a hard water issue - the tiles have only been laid for a week - is this enough time for deposits to form? From other searches on the web for this issue, I found something referring to latex leaking out from the grout as a result of it separating from the other elements in the grout becuase there's nowhere for it to evaporate to (other that out through the grout). Would this make sense (given that all of the materials around about the grout and under it are completely impermeable?)

Thanks again, and for the welcome

Johnny

Polymers can raise to the surface and cause whitening...this is caused by excess water and over rubbing when washing off...If this is so then it's a re-grout or grout colourant..

I doubt it is efflorescence but thats worth thinking of as well...cover all avenues before a re-grout...Try lithofin cement away first and see what this leaves...

How succesful would a grout colourant be? Regrout will be a time consuming job and I can't face a fight with the contractor as to whether he should have thought of it (pretty sure he'll just say that he following the instrcutions ont eh box), so I'd have to pay for it again

as Dave says,probably not mixed properly.

Hi johnny... not a case of following the intructions on the box so to speak...if you have grout whitening , be it polymer shading or efflorescence it is down to the fixer using to much water...incorrect mixing or grouting to early..before adhesive has fully dried...

Have you got any pics..?

How about the pH-value of the bath water?

Could be efflorescence or grout that has been over worked you could use Aqua mix grout colour to give you the clour you like.

hi johnny sounds like calcium you could try(dont laugh) clr CLEANING AGENT but it could be your membraine (you said its 1 week old ) the good ones take 7 to 14 days befor they are set

Guys thanks for the responses. I still can't work out what it is, but it seems now to have stopped developing any further white areas. I'm thinking that I just go with colourant - Acqua mix sounds like a good idea.

Jay I'm not sure what you mean by membrane?

hi johnny membrane or waterproofing i think you call it tanking over there its basicaly a barrier applied by the tiler prior to tiling most take 7 to 14 days before they can be used

Jay i wasn't around when the build was done but i understand that there was a fibreglass structure put in to proof the thing and they did leave a week or so before tiling over so I don't think it is that.
When you mention calcium, how does this arise?

hi johnny calcium mainly caused by hard water( to many minarals or solids in your water ) can also be made worse with cement adh or grouts often see it more on tile line of new swimming pools but grouts are not all the same some are well known for this