new tile grout dark and patchy

I just grouted some new ceramic wall tiles which were installed on a combination of green board and cement board. The color is supposed to be light grey but after 48 hours 20% of the grout is still dark as the color of wet grout. The cement board or the green board alone aren't the problem as it shows on both. I let the premix glue dry for 24 hours before grouting and followed the manufacturers instructions. (power mix for 5 minuted, let stand 10, mix 2 minutes more. I contacted manufacturer and they said to wait another day. I don't think its getting any better. Has anyone had thyis problem Frank

Reply to
Frank D
Loading thread data ...

formatting link

1st & 2nd Paragraphs....

Regards,

Reply to
Ed

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.