We love tile. We hate grout. (If not yet, soon.)

It's true that most tile doesn't take much maintenance. Most of it is impervious. Just sweep it, wash it and it can last decades, maybe centuries.

But grout, the concrete-based mortar-like stuff between the tiles? It's porous. Walk on it and it collects dirt, grease and pavement oils from the soles of our shoes that don't come out with the scrubbing that brings the tile back to its original look. Put grout in a humid bathroom, and it turns into a science project in short order.

Maintaining grout ranges from DIY bleaching and the use of other grout-specific cleaning potions (usually with scary sounding ingredients and demanding instructions) -all of which have one shared ingredient, lots of elbow grease - to calling professionals to do the cleaning or to re-grout the tile.

Ideally, there are two main ways to keep it from getting dirty and stained, says Rob Edwards, owner of Arizona Tile & Grout Care Inc. The answers are part of the instructions Edwards says he leaves with customers after he cleans or cleans and restores their grout to its original color.

"It's the same stuff they should be doing before they hire me," says Edwards. "Keep the dirt outside, if you can. Keep a pair of house shoes or slippers. But people say 'I don't want to not wear shoes in my house.' But they're bringing in blacktop from outside. Look at the bottom of your shoes." He says the oils from asphalt, the stuff that almost immediately stains the soles of a new pair of white athletic shoes, is the main offender.)

That instruction often doesn't get a warm reception, Edwards says. Even after 15 years of rehabbing tired and damaged grout - and a specific license from the Arizona Registrar of Contractors just for doing grout and tile cleaning and repair work - "I have customers who look at me and say, "I'll see you next year, because I'm not going to do that."

Secondly, he says, washing the tile is crucial in staining grout - or not. "When you don't change your mop water often enough, it (dirt) gets into the grout."

It makes sense, as the grout joints are the lowest point on a floor, where the water - and the dirt suspended in the water - settles. And, because the grout is porous and the tile usually is not, the grout readily takes the dirt stain. "Change the mop water as soon as it starts to look dirty," Edwards says.

Edwards says the vast majority of the grout jobs he's hired to do involve cleaning the tile and grout, and then color-sealing (also referred to as stain-sealing) the grout with a urethane-based colored coating. In rare cases, when grout is nearly new or in exceptionally good condition, he says he can sometimes get by with merely cleaning the original grout and sealing it. But, most often, he says the answer is to use the tinted sealer, which will keep the grout looking good indefinitely. Although he said the coating is urethane-based, it's not shiny and can be matched to the color and finish look of the original grout. He swears no one will know they're looking at a coating, not the original grout. He says special caulking can be used to repair cracked or missing pieces of grout before the tinted color sealer is applied.

Edwards says he's only seen a handful of cases where grout was so badly stained and damaged that tile had to be re-grouted.

He warns against bleaching grout to remove stains. He said bleach makes the concrete-based material even more porous and, thus, even more susceptible to staining.

Once grout is resealed, and if it's properly maintained, Edwards says the water-resistant coating will keep it from getting stained for a long time.

Edwards says prices vary greatly, and are set on a case-by-case basis. He said prices are usually by the square foot, but also depend on the overall size of the job and the condition of the grout.

Prices start at 50 cents a square foot for cleaning and $1.50 and up a square foot for stain and color sealing.

Roll Up Your Sleeves?

Homeowners can buy tile and grout cleaners, and a color sealer matched to their grout, the same ones most of the pros use, says Michele Cole, manager and sales representative at Industrial Chemical of Arizona, 5302 E. Pima St.

But while the same cleaners and sealers many of the grout pros use are available to the general public, there is another ingredient that they will have to provide themselves, says Cole.

"We are all still looking for a miracle product. It would be nice to find a product to throw on and have it do all the work for you," says Cole. But ultimately, she says, elbow grease, hard labor, is a key ingredient in all successful DIY grout restorations.

And to help with that, ICA carries a line of mops and scrubbers for cleaning tile and grout, and applying color sealers - and maintaining them afterwards.

"I have grout brushes that are narrow, and you can put them on a pole," Cole says, for those who want to do the job standing. "Or you can get on your hands and knees and use the good old-fashioned grout brush."

Cole says tile and grout cleaners and sealers don't have to be chemically harsh. She favors Procyon tile and grout cleaner, a "Green Seal" (environmentally friendly) cleaner ICA carries. And she says there are a number of other products, both oil- and water-based sealers in a variety of colors. Most common grout colors are in stock, and others can be special ordered, Cole said.

"I have a lot of colors in stock. But if you want a specialty color, it takes five to seven days to get it," Cole said.

She said ICA carries material to repair damaged - cracked or missing - grout, too.

Like Edwards, Cole stressed the importance of mopping.

"Before you color your grout you want to make sure it's clean, because any dirt or grease will repel a sealer," Cole said. "The important thing is a good mopping technique. A lot of people don't like to do that. We usually recommend a string mop. It's like washing the hood of the car. Flood mop (a section of the floor) and let it get wet for a while and clean it up with a wrung out mop."

As for grout mold, Cole said even sealer won't eliminate that forever. "Nothing is going to prevent the mold. It's all airflow. A lot of the older houses don't have airflow. With moisture you can't prevent it," Cole said.

Dan Sorenson can be reached at dan.sorenson@pobox.com