Grout color changeing Page: 3

[Steve_Bcs]

I'm a reasonably competent diy'er & tiled a few bathrooms and kitchens over the years ( I'm 60). Patching just happened to me as yesterday using Mapei medium Grey 112 with grey 10mm porcelain slightly textured surface. Never had this before. I shook the bag but only mixed half, carefully weighed grout & water carefully measured, then mixed using a mixer ( drill attachment), left for a couple of mins and mixed again . Grout went on great and when started to dry, I used a very wrung out sponge (clean water) to carefully wipe excess grout off the tiles but not the joints. Wiped all over after about an hour - but again with only a barely damp sponge. All looked fine but this morning parts looked darker. I did try lightly sanding around one tile (to be covered by a mirror) and it did the trick but what a complete faff to have to sand more or less every joint to ensure an even colour, there has to be a better way and disappointing that Mape's answer is to resort to sandpaper. I did a metro tile spashback last year using silver grey - from Topps Tiles but cant remember the brand- not Mapei, was is a dark blue & white or blue & silver bag if memory serves. That went on using same method & dried perfectly and yet Mapei are peddled as the best grout on the market but with seemingly zero tolerance - even pro Tilers experiencing issues so it cant really be the tilers I wouldn't have thought.

 

[Bathfix Bob]

Ultra titanium does this aswell, dark patches.

 

[Mapei UK Marketing]

I'm a reasonably competent diy'er & tiled a few bathrooms and kitchens over the years ( I'm 60). Patching just happened to me as yesterday using Mapei medium Grey 112 with grey 10mm porcelain slightly textured surface. Never had this before. I shook the bag but only mixed half, carefully weighed grout & water carefully measured, then mixed using a mixer ( drill attachment), left for a couple of mins and mixed again . Grout went on great and when started to dry, I used a very wrung out sponge (clean water) to carefully wipe excess grout off the tiles but not the joints. Wiped all over after about an hour - but again with only a barely damp sponge. All looked fine but this morning parts looked darker. I did try lightly sanding around one tile (to be covered by a mirror) and it did the trick but what a complete faff to have to sand more or less every joint to ensure an even colour, there has to be a better way and disappointing that Mape's answer is to resort to sandpaper. I did a metro tile spashback last year using silver grey - from Topps Tiles but cant remember the brand- not Mapei, was is a dark blue & white or blue & silver bag if memory serves. That went on using same method & dried perfectly and yet Mapei are peddled as the best grout on the market but with seemingly zero tolerance - even pro Tilers experiencing issues so it cant really be the tilers I wouldn't have thought.

Good Morning,
As a general rule of thumb we would never recommend part mixing the grout as it is next to impossible to get the same quantity of the various chemicals mixed, as when mixed as a complete bag, hence the final finish appears patchy.

 

[Steve_Bcs]

Ok, not sure I read any literature to that effect? Could you point out where I might find that nugget please?

 

[Dumbo]

Ok, not sure I read any literature to that effect? Could you point out where I might find that nugget please?

They got a whole list of possible causes of everything .

 

[Julian 'Farmer' Bonsall]

I don't think I am capable of grouting 5kg of UCP in one go by myself. I haven't had a problem personally and have used UCP for the few jobs I've the last year or so. I didn't know I wasn't supposed to only use part of the bag (I do my best to tip it end to end a fair few times before I use it).

Are these problems more likely with certain tile types ? Are certain Mapei adhesives less likely to be linked to this? (I used mapeker rapid set last time).

[DiYer]

 

[Glynn]

Other grouts are available😛.

 

[Dumbo]

Other grouts are available😛.

Not in my tile shop . So please try harder to get them in .

 

[Time's Ran Out]

Grouted in Tilemaster 3000 natural grey.