Efflorescence

[ajs201277]

hi there i have had my bathroom walls and floors tiled in real slate and grouted with granfix maxigrout black grout but the joints have turned grey in various shades through effloresence i think but the tiles have been sealed could anybody tell me if i can darken the joints back down any suggestions would be very helpful
thanks adam

 

[DHTiling]

Hi Adam...

I doubt it is efflorescence...it is more than likely polymer shading .. which is very common in coloured grouts if instructions are not followed to the T...

You can use a grout colourant to solve this issue...But firstly..has the grout been sealed..?

 

[diamondtiling]

Granfix's black grout dries.........dark grey. I have used it and argued at the shop but they take no notice so I don't use them any longer.

😛rrr:

 

[tfs]

I heard that tile giant stopped using granfix as there where too many come backs with there products. Doubt they will have this issue using a brand like Mapie though

 

[ajs201277]

thanks dave for your input yes the grout has been sealed

 

[DHTiling]

thanks dave for your input yes the grout has been sealed

Ok...you will need to remove the sealer...then leave it to dry...

2 grout colourants you can use...first is mapei fuga fresca...and the second being Aqua mix grout colourant which is epoxy based ..once applied and dried then you can re-seal the stone with the same sealer..


You MUST make sure everything is dry before each step....there are members on tilersforums who have used the colourants and will explain on the ease of use..

Just to add though and this will be the easiest method...strip the sealer and then leave to dry and seal with Aqua mix enrich and seal..this will darken the grout to a more uniform colour but will also darken the stone..what type of finish do you have now..matt or gloss.?

 

[ajs201277]

gloss finish what would i use to strip the sealer

 

[ajs201277]

would i need to strip just the grout joints or everything

 

[DHTiling]

You will find it hard to just strip the joints...what sealer was used in the first place..?

 

[ajs201277]

larsen impregnating sealer