why does bal grout always discolour (grey and black goes slightly white in patches)? Anyone know if there is anything that can be done to stop this happening?

Are these the super flex ones you are taliking about...? and welcome to tilers forums..

Thanks for the welcome,
Yes BAL super flex wide joint, the charcoal goes white in places and the grey goes light grey in places. Clean buckets and correct mixture used both times, limescale and salt in the water also ruled out as the charcoal was used in a skiing chalet in the Alps where the water is pure.

This happens with some modified grouts..especially the BAL ones....limestone is just as bad.....what happens is when washing off....if you use excess water when washing off it brings out polymers in the grout and when it dries this is the whiteness.....thats why i asked if it was the super flex range....

It is also a possiblity that it could efflorescence, either from the adhesive bed( not fully cured) or a draft or again excessive water from washing off........my money lies on the polymers...coz BAL grouts are very prone to this....as for cure...then a quick lick over with fresh grout and minimal water when cleaning off........

Thanks Dave,

Do I have to scarpe out the floor grout first before the fresh lick?

Here are a few pointers on difficult grouts:

• Mix exactly according to the specs. If it says 1l water to 5kg powder on the bag, then that's the ratio you should use. Not more, not less.
• Mix with a low RPM mixer, using a grout paddle, to avoid mixing air into the the grout. Mix for about two to three minutes, and then let the mix slake fr five minutes, and then mix it again for about one to two minutes.
• When the grout is applied, leave it long enough for it to not stick to your finger, or "move", when you touch it, before cleaning it.
• Use a washboy and a sponge float to do the first rough cleaning. Make sure the sponge float is merely damp, as opposed to wet, and go over the grout in a circular motion, evening the joints. Don't rinse the sponge to often; the more muck there's on it, the better, and the less water the grout is subjected to.
• On this stage, I normally go over the grout with the sponge float, rinsing it about once every 50 linear cm, but if the grout is REALLY sensitive, I use a damp microfiber rag instead. I normally use those for the final polish, to remove any grout haze. Though they are slower at actual cleaning, they require less water than sponges, and that can mean the difference between patchy joints and perfectly uniform ones.

The thicker the rag, the better imo, but keep in mind that they're slower than sponges, and harder to use, so don't do as much in one go as you normally would. Don't buy cheap ones, as they might leave lint in the grout.

Originally Posted by Versatile69

Thanks Dave,

Do I have to scarpe out the floor grout first before the fresh lick?

depends on how flush it is with the tile surface..all you are after is colour change not grip..so to speak...

follow sWe's guide and you will be fine..

In most cases a coating of Aqua Mix Enrich & Seal will even the colour out it saves so much time and grief of redoing the grout and works in 95% of cases. Just do a test area first to be sure and allow it to dry for 24 hours you have nothing to lose othewr than a days wait

Kev

Originally Posted by TilingLogistics

In most cases a coating of Aqua Mix Enrich & Seal will even the colour out it saves so much time and grief of redoing the grout and works in 95% of cases. Just do a test area first to be sure and allow it to dry for 24 hours you have nothing to lose othewr than a days wait

Kev

Doesn't that darken the grout colour though kev...what is the customer doesn't want that..?

Originally Posted by Versatile69

why does bal grout always discolour (grey and black goes slightly white in patches)? Anyone know if there is anything that can be done to stop this happening?

most of the problems i have seen with bal white grouts turning grey is because the adhesive is not dry usually bucket adhesive to thick around windows larger tiles ect and the water can only come out through the grout :Pete