Patchy Mapei grout... any ideas?

[samboughton]

that makes sense as its a wetroom and where the huge wall tiles are around the shower area he dotted the adhesive instead of spreading it. The grout there is fine and its fine on the floor where the adhesive was left over a weekend to dry out. Its just all the other areas on the walls. My solution was to do an acid clean as ive read about the darker areas being polymers?? then painting silver/grey Universeal grout colour.. do you think that sounds like it may work? I think its going to be down to be to tell him how to fix it or i'll have to fix it.

 

[Gazzer]

How large are the tiles, dot and dab with dispersion adhesive ....Oh dear

 

[macten]

Wetroom, dispersion adhesive, large format tiles, dot and dab ........ think the patchy coloured grout maybe the least of your troubles I'm afraid to say

 

[samboughton]

hmmm... be helpful if you could say a bit more on that... its been a fairly specific job. expensive tiles etc.. then this grout issue has pretty much ruined the overall look.

 

[macten]

I don't wish to be accused of scaremongering or tell you your wetroom is doomed to failure as that may not be the case but from the information you have given the job has been done incorrectly with regard to technique and materials.

Tiles over 300x300mm are classed as large format and ready mixed adhesive is not suitable for the reason that it dries by dispersion - I've removed big tiles that have been fixed with ready mix and the center has still not dried after 2 years.
Even if your tiles were smaller most tilers would use a bagged adhesive in a wet environment.
The adhesive should be combed on to the wall with an appropriately sized trowel as well as buttering the backs of large format tiles to achieve the 100% coverage that is needed in a wet use environment.

The above is just going on what you have mentioned, and would like to also ask:
What size and thickness is the tile?
What type of tile is it? (ceramic, porcelain, natural stone)
What are the walls that were tiled made of?
What kind of waterproofing (tanking) system was used?

 

[samboughton]

Thanks guys, who's replied.. It's really helped me out. A week later it's SLIGHTLY improved but at least I've been able to discuss it with the tiler armed with some knowledge!! It's horrid being a customer to a trade you know nothing about but the result is a mess!!! A good site for hands on proffesional advice.. Not JUST comments..

 

[Dan]

Just bumping some of the older popular (sometimes not so popular) threads. Probably wont be current discussion these days but I just need to do it. So just ignore the thread if it's not current for you.

 

[inbloomgardens]

Hi, looking for help, having my bathroom done and we've chosen Manhattan Grey colour and it's dried/drying darker in patches and it's left my builder stumped as to why. He used a grey adhesive to fix the tiles and left them overnight to set before grouting.

 

[Boggs]

How long has it been drying for?
It can take several days.

If it’s still patchy use this

FUGA FRESCA

Easy to use grout refresher to rejuvenate the colour of cementitious grouted joints in floors and walls. May also be used to correct irregularities in colour due to incorrect grout application. Helps obtain a uniform colour which absorbs less water and is easier to clean. Where to use: Fuga Fresca…

www.mapei.com

 

[inbloomgardens]

The initial area was done 5 days, been reading the thread and might try the hairdryer solution when the builder goes home. Will give that a whirl though