No one will argue that tile flooring in entrance-ways, kitchens, bathrooms, or even patios is practical, hard-wearing and low maintenance. However, no matter where tiles are installed they all have one common flaw — the grout that holds them in place.
Since tile grout is porous, it tends to catch and hold dirt and water, which slides off the much harder (and non-porous) tile surfaces into the grout. Even worse, grout can crack, leaving unsightly gaps between the tiles. Once that happens, you need to remove some of your existing grout to restore your tile’s original appearance.
Step 1 - Remove Old Grout From Seams
Grout isn’t designed to be removed, so removing it is a time-consuming and messy job. It definitely requires some sweat equity. For your new grout to get a solid grip, remove the old grout to at least 3/16-inch below the tile surface. Getting the old grout out is the hardest part of this restoration, but you do have some options on how to go about it. How much sweat equity you need to invest will depend on the option you choose.
Power Tools - The quickest and easiest way to get grout out is with a dremel rotary tool or oscillating tool, equipped with an attachment specially designed to cut grout. You simply guide the tool along the grout lines, making quick work of removing the grout. Although fast, this creates quite a bit of dust and mess and if the tool happens to slip out of the grout line, surrounding tiles can be ruined.
There are also grout removing blades that fit onto a reciprocating saw, which are effective but harder to control, and single use power tools, designed specifically for grout. These are effective, but unless you have a lot of grout to remove it makes more sense to purchase a multitasker like a rotary or oscillating tool.
Grout Removal Tool - This is essentially a metal rod with a triangular shaped carbide or diamond cutting blade on the tip. These tools are inexpensive (probably less than $20) and available at most home improvement or tile stores. You place the triangular tip into a grout line and push the tool forward so the tip cuts through the old grout. You do need to apply a lot of pressure to cut through the grout, and if the tool slips, it can cause lots of damage to the surrounding tiles.
Hammer and Cold Chisel or Flathead Screwdriver - This is the old tried-and-true way to chip out grout. Hold the chisel or screwdriver at a 45 degree angle to the grout and just chip out the old grout by tapping on the handle with a hammer. Once you get the first piece out, back up and chisel towards the gap. Getting rid of grout this way takes lots of time, but it works and if you work carefully, you’re not likely to damage any of the surrounding tiles.
No matter which option you choose, be sure to wear safety glasses. If you go with the rotary tool, wear a dust mask as well. Use a vacuum and a damp cloth to get all the dust and any loose pieces out of the grout lines.
Step 2 - Mix Your New Grout
Mix a batch of new grout in a clean bucket following the package directions. (Be sure you’ve got unsanded grout if you have any grout lines 1/8-inch or less). Your mixed grout should have a consistency similar to cake icing. Only mix up as much as you can use in about 15 minutes, or it will start to set up before you get to it. If that's not enough for the whole job, mix up more as you go.
Step 3 - Apply Grout
Using a rubber-backed grout float, apply the grout, working across the grout lines at a 30 to 45 degree angle. Be sure to press the grout well down into the cracks. If there are some places the float can’t get into easily, use your hands to press in the grout.
Once all the grout lines have been filled, hold the float at a 90-degree angle to the lines and wipe away as much excess grout as you can. Let the grout set up for about 15 minutes (read the package directions).
Step 4 - Sponge the Surface
Using a soaked grout sponge and a clean bucket of water, wipe the entire surface. Keep rinsing the sponge to make sure you’re wiping with a clean surface and you’re actually removing the excess grout, not just smearing it around. After the first wiping/rinsing, you can pack the grout down into the cracks and give it a nice finished appearance by gently sliding the handle of a toothbrush along the lines. Now, give the whole surface another wipe, using your damp (not soaked this time) clean sponge.
Step 5 - Wait and Seal
All that’s left is to let your grout set up overnight, and then give it a final wipe with a clean dry cloth or sponge to get rid of any leftover grout haze. Let your new grout set up for four or five days and then give it some protection against dirt and stains by applying a grout sealer. Now just stand back and admire your new tiles.
That's all there is to restoring your tile grout! Now that you’ve applied the grout, learn how to clean it.