Two issues with Mapei Ultracolour Plus grey grout

[Asil1205]

Hi,

I have recently grouted a bathroom with mapei ultracolour plus manhatten grey grout and have a couple of issues in places. It's the first time I've grouted.

Firstly, after roughly a week of use a few grout lines very near the shower appear to have lost small pieces of grout from the surface:


Secondly, as soon as I had grouted I noticed some areas where the grout was very dark and have realised from searching online that this was probably due to excess water. I decided to just put up with it but I have now noticed that on the dark areas there are what look like drip marks where the colour has lightened:



I am most worried about the first problem meaning that water will get in and behind the tiles, but any advice regarding either problem would be greatly appreciated, thank you.

 

[Dan]

Looks like it was too wet or had been remixed with more water once it started to set in the bucket.

Just my opinion.

 

[Asil1205]

Looks like it was too wet or had been remixed with more water once it started to set in the bucket.

Just my opinion.

Thanks.
I didn't add more water to it, but I did mix a second lot without completely cleaning the bucket so grout from the first lot could have got mixed back into the second lot.

 

[Dan]

Try mixing a little bit and going over those spots and then give it a few days to see if it clears up?

Failing that; wait for an actual tiler to comment 🙂

 

[The Bear]

A bit of fine sand paper folded over to create a ‘sharp’ edge over the affected areas , just to remove the surface layer can often reveal a more consistent colour. Good luck

 

[Asil1205]

Thank you both for your replies. I tried the sandpaper over the darker areas and it improved the appearance.

Since I last posted I'm now finding very dark patches appearing in areas that were a pretty consistent colour before.

They remain hours after the shower has been used. I'm concerned I've made a terrible job of this and am going to have to rake out and re-do. Can anyone advise on this? Is it just caused by the same problem as before where too much water was used when mixing/cleaning? Or something else

Thanks you in advance.

 

[Qwerty]

Buy some Mapei Fuga Fresca

 

[Dumbo]

I was going to same as @Plan Tec Tiling .

 

[Sean Kelly]

Or better still (in my opinion) Universeal Grout rescue).

I've tried both and the Grout rescue is a far superior and more user friendly product. However, I would advise purchasing the pre cleaner too.

 

[GoneGuy]

Try fruga Fresca first

 

[hmtiling]

Or better still (in my opinion) Universeal Grout rescue).

I've tried both and the Grout rescue is a far superior and more user friendly product. However, I would advise purchasing the pre cleaner too.

the pre cleaner won't be needed on brand new grout

 

[Sean Kelly]

the pre cleaner won't be needed on brand new grout

That's what I thought a couple of weeks ago.

I spoke to one of their tech guys who told me to always use the cleaner even on new grout. Think of it as a primer he said.
I for one will always use it in future.

 

[hmtiling]

That's what I thought a couple of weeks ago.

I spoke to one of their tech guys who told me to always use the cleaner even on new grout. Think of it as a primer he said.
I for one will always use it in future.

Sounds like a sales pitch to me. I've used fuga fresca and grout rescue on new grout and it takes very well. On old grout the pre cleaning is essential

 

[Italy]

you have already tried a first cleaning with the keranet
or similar?

https://cdnmedia.mapei.com/docs/librariesprovider2/products-documents/152-keranet-gbfd02f77779c562e49128ff01007028e9.pdf?sfvrsn=2bf29507_0