Grout and tile are different surfaces. But, because we clean them both at the same time, you have to know the difference.
Tile tends to be factory-finished and non-porous; grout is porous and soaks up everything. Chances are, bacteria is living in your grout, causing odour. Porosity can be our biggest problem or our greatest advantage. (You may want to keep reading.)
Tiled areas often contend with dirty liquids (think entrance ways, restrooms, and kitchens). Grout, being porous, soaks these dirty fluids up; tile rarely soaks up anything.
Once the grout has absorbed as much as it can, routine cleaning is no longer effective. The bad news: it’s beyond mopping at this point. Often, the grout soaks up so much grime that it changes colour. Look in the corner of the room, behind a toilet, or under a semi-stationary object — a place where less foot-traffic reaches. When comparing that section to a well-used one, you’ll see signs of colour change.
Now for the good news: you can use the porosity of grout to your advantage. Here’s what you need to do:
The sealer will soak into the grout lines (just like the grime does). After the grout has been sealed, it will no longer be able to soak up dirty fluids.
Once the grout has absorbed as much as it can, routine cleaning is no longer effective. The bad news: it’s beyond mopping at this point.