Granfix Grey Grout Dried Different Colours - Tile Advice

[Ivan Rubery]

Hi all
Please advise needed if possible. How can i fix grout that has dried different shades. It is meant to be grey, but is grey and black in different parts. I treated each wall area separately as not quick enough to grout whole bathroom in 1 go, so therefore different batches were made, everything clean each time, mixed to smooth paste as per instructions. I have seen some info on efforensense, but not sure if it is that. Would it be possible or feasible to go over surface again ? Is Granfix grout any good as i have used mapei before with no issues ?

 

[Dan]

Do you have any pictures by any chance?

 

[Dan]

Also what adhesive was used and was is the substrate? Plaster or plasterboard or something else?

 

[SJPurdy]

Is the colour uniform in each wall/batch area? or is it patchy throughout a single mix batch?

I think Effervescence is when, as a grout sets the moisture in it rises to the surface bringing more of the salts in the grout to the surface and this gives a lighter/whitish colour to the surface of the grout ( if this is wrong then someone please give a correction). I personally used to find this to be a problem with Granfix grey floor grout and so stopped using it.
I however have never seen grey/black patchiness but it could possibly be effervescence on black grout giving lighter greyer patches; but, I do not think, darker black patches on grey grout.
There are (acid based?) products available to reduce effervescence if this is the cause.

Pictures would be useful to help with a diagnosis.

 

[Old Mod]

Well effervescence is gas bubbles in a liquid haha sorry Steve couldn't help it!

Efflorescence is the formation of salt crystals after water carrying these salts evaporates.
Most common cause is over washing with a sponge that is saturated with water or standing water in the joints.
If it's light and dark grey it could well be efflorescence.
Grey grout is dark when wet, efflorescence would turn it light grey.
How long has it been since u've grouted?
Or has the area been subject to premature heavy wetting?
Or is room very humid?
Or even grouting too early I'd addy hasn't set properly.
These can cause efflorescence
(derived from Latin word meaning "To Bloom")

U can generally remove it with a Phosphoric acid based tile and grout cleaner.
Obviously test small descreet area first.

 

[SJPurdy]

Well effervescence is gas bubbles in a liquid haha sorry Steve couldn't help it!

I deserved that - spell checker corrected my first miss-spell and then I copied it, every time thinking it didn't look right

 

[Tile Shop]

Well effervescence is gas bubbles in a liquid

You mean like when you trump in the bath? What latin word does that derive from?

 

[Old Mod]

You mean like when you trump in the bath? What latin word does that derive from?

Fervere!
(to boil)

 

[Ivan Rubery]

Is the colour uniform in each wall/batch area? or is it patchy throughout a single mix batch?

I think Effervescence is when, as a grout sets the moisture in it rises to the surface bringing more of the salts in the grout to the surface and this gives a lighter/whitish colour to the surface of the grout ( if this is wrong then someone please give a correction). I personally used to find this to be a problem with Granfix grey floor grout and so stopped using it.
I however have never seen grey/black patchiness but it could possibly be effervescence on black grout giving lighter greyer patches; but, I do not think, darker black patches on grey grout.
There are (acid based?) products available to reduce effervescence if this is the cause.

Pictures would be useful to help with a diagnosis.

Hi there

I have added some pics, but not really easy to see. After some searching today, the suppliers (BB) have said they supplied the wrong colour grout, should have been light grey, but was charcoal. Customer wants me to re - grout the bathroom !!!!(21 SQM). Any tips/help/advice would be most welcome (not looking forward to this !!!!!) I will be paid extra for this, but dreading it already. is there an easy way to do this|?

 

[Mr Tiler]

That tiling looks a bit funky

 

[Dan]

Grout lines look like they've been washed off way too much. Tiles are stepping quite a bit.

Not the best tiling that.

I thought you were DIY when you first asked but you say this is a customers job. :-/

You need a tool like a Fein Multimaster with a grout removal head on it. (Available from www.TradeTiler.com) or a grout rake (also from TT). But it'll take you ages with a rake. Then re-grout.

 

[Ivan Rubery]

Grout lines look like they've been washed off way too much. Tiles are stepping quite a bit.

Not the best tiling that.

I thought you were DIY when you first asked but you say this is a customers job. :-/

You need a tool like a Fein Multimaster with a grout removal head on it. (Available from www.TradeTiler.com) or a grout rake (also from TT). But it'll take you ages with a rake. Then re-grout.

Thanks for comments, taken on board. Not too sure what funky and stepping means ? I am learning, still a way to go. Another question, is there a minimum bed thickness for floor tiles to stop height of floor being raised too much ?

 

[Dave]

Did you use bucket adhesive ( ready mixed ) ?

 

[Ivan Rubery]

Did you use bucket adhesive ( ready mixed ) ?

Hi Dave
Yes ready mixed bal white star for walls

 

[Dave]

Hi Dave
Yes ready mixed bal white star for walls

It's more than likely moisture evaporation causing the dark patches , if you grout to early when using a dispersion adhesive , then staining can occur as the moisture leaches through the joints.