A. Ah the old adage " tile makes you smile, grout makes you pout". There's not a definitive answer to sealing grout. Myself, I prefer not sealing. Most grouts these days are poly modified, which helps in keeping stains from penetrating. As long as you wipe up a spill quickly before it soaks in, the grout will be unscathed. On the other hand if you use sealer on the grout this can also help in preventing stains, but the life span is usually short. Nominally a year. Less if you mop your floor regularly. Keep in mind this is about staining not how dirty the grout gets. The grout will get dirty no matter what you do or do not. Some sealers will also change the color of grout (usually darker) which my not appeal to you. Another thing is, you do not put sealer on most tile surfaces. The sealer will not penetrate and just sit on top, leaving a sticky residue behind, which can be a daunting task to clean up. Only certain tile surfaces, like natural stone, i.e. travertine, should be sealed. Which is necessary because the stone is prone to staining. Also you shouldn't seal the grout in showers. The grout needs to "breathe". Sealing it traps the moister trying to evaporate from behind. To understand this is to look at a cold glass of water on a hot day. The condensation you see on the outside of the glass is the same thing that's happening behind your walls when you take a hot shower. The air behind the wall is normally cooler which then condenses on the wall. Most of it will trickle down to the shower pan, but some will soak into the wall and into the grout. Insulation behind the wall hinders the evaporation process also. So if you seal the grout' you in essence create a vapor lock. Locking in that moister, creating mildew, of which you were trying to avoid to begin with. Simple maintenance would prevent that mildew from growing. See "How do I keep my shower looking new"
If something does accidentally stain the grout it can usually be removed by using sulfamic acid. That's Sulfamic not Sulfuric. This is a very weak acid, a little stronger than vinegar and its safe to use on all tile. It normally comes in a crystal form, looking a lot like sugar. It comes this way because once you add it to water the strength starts diminishing after 24 hrs. You can make a bottle of solution by adding a tablespoon to a quart size spray bottle. Fill bottle with cold water and shake to dissolve the crystals. Spray the area your working on. If you need to, you can lightly scrub with a hand scrub brush, (to break up the dirt). Then mop up with clean water using a large hand sponge. Wiping with one side of sponge and flipping over and wipe with other side. (See “ What is the best way to clean my tile”) Do not wipe back and forth. This will just put what you wiped up back on the floor. Change the water in bucket once dirty.
