HELP Hairline cracks in grout

[merlecollins]

Hard to believe Ultracolor cracking like that:yikes: - was it mixed too watery?

This is a super strong cementitous grout, something is adrift here....

What tiles were used?

 

[DavieA]

I mixed it to a creamy constancy but wouldn't say it was too wet. Added slightly more water than the instructions but it does say approx depending on colour. Never had an issue before. But you sound like you have more experience with this stuff than me so am open to any advice. Oh and ceramic tiles.
My answer any help? Trying to give as much info as poss.

 

[DHTiling]

I mixed it to a creamy constancy but wouldn't say it was too wet. Added slightly more water than the instructions but it does say approx depending on colour. Never had an issue before. But you sound like you have more experience with this stuff than me so am open to any advice. Oh and ceramic tiles.
My answer any help? Trying to give as much info as poss.

where does it say that..?.. same water ratio for all colours.

 

[jamie B]

only time I've experienced any probs with ultracolour was once grouting a floor whilst the heating was being tested, being a small room, it went off like a rocket and gave some 'blooming' to the tile..that night the floor got walked on and hairlines appeared at the tile edge..almost like the tile biscuit acted as a radiator (they were hot to touch around the rad/towel rail) and baked the grout dry too quick. As advised above I'd rake (which will be tough!) and re-grout affected area as a start...and close off the floor over night!..best of luck!

 

[DavieA]

Im sure it said "approx depending on colour" on the mixing instructions but i may be wrong. Ill rake effected are and re grout taping off room so no one walks on it think ill also make sure the heatings off because it too is a very small room and gets warm quick (4m2 and has 2 yes 2 Rads!!) and sounds like maybe because of either the wrong consistency or the speed it dryed that its not gone off correctly because the lines are along the tile edges where the grout and tile meet. (or thats what im hoping anyway).

OR

Its a movement issue
:yikes:

 

[The Legend; Phil Hobson RIP]

Only had a quick skim through this, but at 1st glance it sounds like shrinkage due to grout drying to quickly. I will stand corrected as I have not come across this myself.