Have you tried a little bleach spray? The Clorox Clean Up always works for me…I spray it and leave it for a couple of minutes, then take a hard bristled brush and scrub a little bit and it usually comes clean. Now as for the reason it’s happening…not sure about that. My grout gets dirty over time with people stepping on it with shoes and what not but it definitely didn’t happen right after installation. FYI I have never sealed any of my grouted tiles and I have them all over my house.

Somebody used the wrong kind of grout, and did not seal it. Next time use urethane or epoxy grout to avoid the problem.

But for now, when you get the existing grout clean, call your tiler and have him/her seal the grout. He/she must have forgotten this essential step in the tiling process.

It’s been two weeks since our guests left. i would think it is dry by now. thanks for that thought.

Starcraft, suggestions on getting it clean? thanks.

"dripped water only on the floor after showering which has caused the grout to now be stained."

Not possible. So treating this as a stain and throwing different cleaning products at it is the wrong approach.

"Somebody used the wrong kind of grout, and did not seal it."

We do not know which exact grout was used to determine that point. Manufacturer, limitations. Were proper installation methods followed and cure times allowed for? Sealed grout will darken when wet. Sealing does not waterproof the joint. Sealing grout is not an essential step as the majority of todays grouts are highly stain resistant. Apply a solvent based sealer to some urethane grouts and you may just ruin it. Do the dark areas continue down through the joint or are they topical?

Point being. We don't know the product used. Therefore providing cleaning and sealing advice is not possible!

What to do. Contact the installer as it is a new installation. Inquire as to the exact product used. If a satisfactory solution is not reached contact the grout manufacturer directly to have a Rep look at the project. Now you will have a report stating facts. Yes the Rep will inquire as to what products were applied by you. Once you touch it a majority of the time you own it.

What Ctec really means is there is a lot of bad advice on this thread, as is on most all tile threads on Houzz.

Hire wisely hire once.

I did mention it was sanded grout if that makes a difference. i will do some research. Thanks.