Guy that use to work for me had a machine that would use an acidic cleaner and had two motorized scrubbing heads.

Hot water, degreaser, brush, let it soak, do it over again, and again. If it's stained, then bleach, which compromises the grout some if it's a cement grout. We have a jet steam cleaner, but I don't think it does any better than a brush. My favorite brush for the job is a fingernail brush with a handle that you can grip. Horrible work. Krud Kutter's my current favorite cleaner.

I sure like epoxy and urethane grouts - they pretty much make grout cleaning a thing of the past.

Hot water, OxyClean, white scrubbie. If that doesn't clean it, it's not going to get clean.

Any acid will help clean but also start compromising the grout.

Considering a good cleaning (degreaser too with fresh water rinse) and then a grout colorant. This one is epoxy based so onced colored, you get a MUCH better seal on the original cementitious grout:
http://www.custombuildingproducts.com/products/aqua-mix/grout-colorant/aqua-mix-grout-colorant.aspx

Second...oxyclean does a pretty decent job but the white scrubby is key...you only use a green scrubby once.

And I have used that colorant a few times as well. Goes on pretty easy. I just brush on with an artists brush and wipe off any that gets on the tile with a damp clothe.

angus242 said:

Hot water, OxyClean, white scrubbie. If that doesn't clean it, it's not going to get clean.

Any acid will help clean but also start compromising the grout.

Considering a good cleaning (degreaser too with fresh water rinse) and then a grout colorant. This one is epoxy based so onced colored, you get a MUCH better seal on the original cementitious grout:
http://www.custombuildingproducts.com/products/aqua-mix/grout-colorant/aqua-mix-grout-colorant.aspx

Click to expand...

I Use Viper Venom http://interlinksupply.com/index.php?item_num=CR22GL&gclid=CPmdlNuL9b0CFaLm7Aod8FgA9Q spray it on let it dwell 15-30 min. I
rinse and recover using a turbo hybrid wand http://www.jondon.com/turbo-hybrid-tile-grout-cleaner.html hooked to a Hotsy 555 and a pumper vac. Works great.
210Deg water at 1800psi is hard to beat on tile.

Bob, Angus,Rob,Chair..... Thank you for the ideas.

(Chair... Thanks for the info... little above my need/capacity for one residential redo.)

So, I just got back from playing with Oxyclean and Clorox.

...(Bob, actually I was using Krud-cutter before... don't know why I got mixed up and called it Ka-boom... it took up alot of dirt,,, but not that great on the grout)).

Oxy did better, but Corox really cleaned up the grout stains REALLY.!!!

I guess my first question to you guys would be... how bad do you think that bleach compromizes the grout. The grout has been down for many years and is fully competant right now.... Would I expect it to crack/crumble at this stage.

Depending on your guys advise, I may go ahead with Custom's colorant,... more so for grout integrity, rather than color aesthetics.

I'm reluctant to follow up with the colorant if I don't need to, for both the time/work, but more so, because the tile is a very rough/ textured (non-skid) porceline .... and I'm afraid of being able to clean the tile with an epoxy based colorant.

Thanks again

Peter

Most of the grout cleaning is the high pressure tool. Of course you need product but the pressure is the biggest thing. To the best of my knowledge many of the original grout cleaning products, ie viper venom, were relabeled floor stripper. Don't think they changed their formulation too much since then unless it's a green product... Make sure you do a good job rinsing it as any product left behind will cause issues with resoiling down the road.

Just rinse well.

MTN REMODEL LLC said:

...how bad do you think that bleach compromizes the grout...

Click to expand...

Bleach can permanently, well, bleach the grout...as in remove color from the pigment.

I've used a product called "Totally Awesome Tile Grout Cleaner" and it works great.