Colour bleeding from biscuit base - does it happen??? - TilersForums.com

[Ragusjohn]

HI
We have just completed 22 sq m of brilliant white ceramic tiles over marmox boards with Ardex X77W adhesive in a bathroom. The adhesive was well dry before we started grouting (several weeks). Started grouting with BAL Micromax 2 in white; we used 3mm spacers for the joints. In several large areas the grout is discoloured a lightish terracotta colour. We thought perhaps it needed to dry out so left it several days but discolouration still very noticeable. Looking more closely it appears that the colour may have bled out of the terracotta-coloured biscuit base of the tiles. The bleeding has occurred on uncut edges of the tiles. It appears more noticeable where the ceramic glaze does not wrap fully over the front edge of the tile and down the edge, but also occurs where there is good ceramic wrap-round.I cannot find any similar threads so has anyone experienced this. Not sure it shows up well in photos but I attach some if it helps. If so, any suggestions on how to solve this problem and avoid it in the rest of the bathroom. We'll have to rake out and re-grout the 3 sq m we have done so far. Joy!
Thanks

 

[Sean Kelly]

The bleed is not coming from the Marmox boards or the adhesive (in my opinion).
The grout is BAL (a good name). The tile is the unknown here. You could test a bit of tile with a damp cloth and see if the biscuit bleeds.

I assume you used clean bucket and grout float?

My only solution would be to use a grout colourant. Search 'Universeal Grout Rescue'. Paint this over the grout. It masks the problem and it is a permanent mask.

 

[Ragusjohn]

Hi Sean - thanks for the reply - yes I used clean water and a brand new float. I am testing some cut edges and uncut tiles today to see if it bleeds. I agree the tiles are the unknown, they are from a reasonable large Spanish manufacturer, sold through Walls & Floors and certainly not particularly cheap! I am thinking that it may have been one particularly batch as the grout lines worst affected are all on tiles in one area which we probably took from the same box. If it is the tiles, I was wondering whether a grout sealant painted into the grout line to seal the tiles before grouting might work.

I have no experience of grout colourant but was concerned whether it would stand up to duty in the bathroom and shower area. Saying that - I'll test anything that might save raking out the grout!

 

[CJ]

ive had before from cheap tiles........very thin glaze, not glazed on edge, damp gets under edge. May, or may not dry out 🥴

 

[Tony_C]

Talk to @Paul C. and see if he has known of this issue before

 

[Etherglide]

Interesting post this. Ive been having grout colour variance with Mapei recently.

 

[Boggs]

Occasionally had a similar problem with Bal MM2 white grout, sometimes had a yellowish colour to it when it dried.

Stopped happening after I started using Tilemaster Grout 3000.

 

[Dumbo]

Its the grout .
Read a page ona social media with proffesionals complaing of this with this grout