How to Regrout Tile

What grout do I use?

Generally speaking, choose grout to match the existing grout. To find out what that is:

1. Cement-based Grout: This is the most common type of grout used in all installations.
   • Sanded Grout: It contains fine sand particles which are visible in the grout (sort of like concrete or mortar). If your grout lines are ⅛ inch or larger, it’s usually a sanded grout. Sanded grout provides better strength and durability, making it ideal for floor tiles.
   • Unsanded Grout: This type is made without sand and is used for narrow grout lines (no more than ⅛ inch). Unsanded grout is commonly used for wall tiles, and delicate materials like glass or polished marble, where scratching the tile surface is a concern. It looks much smoother than sanded grout.
2. Epoxy Grout: Epoxy grout is a durable and highly stain-resistant option, suitable for areas that require superior water and chemical resistance.
   • Epoxy is the the most challenging to work with. It’s usually only found in commercial applications.
3. Acrylic Grout: Sometimes called a polymer modified grout, this is a modified unsanded cement-based grout that incorporates acrylic additives to improve stain resistance and flexibility.
   • Sometimes used with sensitive or delicate types of tiling such as marble.
   • Acrylic grout is often used in areas prone to movement and water, or areas with temperature variations.

Walls are typically not as dirty as floors, so simply make a paste and apply. For floors:

1. Gather supplies. You’ll need a scrub brush (toothbrush or grout brush), baking soda, hydrogen peroxide, and an eye dropper or something similar. Fill the eye dropper bottle with hydrogen peroxide.
2. Sprinkle the baking soda. Try to concentrate it in the grout lines, use a funnel if helpful. Ensure the grout is completely covered.
3. A small section at a time. Using the eye dropper, add the hydrogen peroxide directly to the baking soda. The baking soda should be have a wet paste consistency.
4. Let it sit a few minutes. I usually scrub a bit to mix the baking soda and hydrogen peroxide and loosen any top layer of dirt. Then wait approximately 3-5 minutes.
5. Scrub the grout. Use a scrub brush to vigorously scrub the grout lines. Focus on small sections at a time and apply pressure to remove dirt, stains, and mildew.
6. Rinse and wipe. After scrubbing, thoroughly rinse the area with water to remove the cleaning solution and residue. Use a clean cloth or sponge to wipe away excess moisture.
7. Dry and inspect. Allow the grout lines to air dry completely. Once dry, inspect the grout for any remaining stains. If needed, repeat the process or consider using a grout sealer to protect the newly cleaned grout.

Matching Color

I don’t attempt to match the color until the grout is clean and dry. Wet, unsealed grout is often darker.

If you have some grout broken out, you can take it in the store to match or many companies have a paper color guide in the store. Don’t use online color guides; your monitor may alter the color.

If you cannot match the color, or if stains make the grout uneven, it’s best to regrout the entire surface. In this case, you only have to remove ⅛-3/16″ or a few millimeters off the top.

Removing grout means A LOT of dust. I recommend wearing a dust mask and eye protection if you’re planning to use power tools.

• I HIGHLY recommend an oscillating tool with a grout removal blade. Not only does it work quickly without causing damage, but it gets right up next to the tile for a straight grout line. This is essential if you’re planning on a color swap.
• These instructions work well for ceramic, porcelain, or stones like travertine and granite. I’ve even changed the grout color on a polished marble floor.
• When doing large home improvement projects save a few tiles, floorboards, or bricks for the possibility of future repairs.
• Clean all dust and debris before regrouting. Use a brush as well as a wet/dry shop vacuum and wipe the tile surface with a damp cloth for a thorough clean.
• For small jobs, using a premixed grout makes the job a bit easier.

Grouting tile comes with a unique set of challenges. Here are a few you may run into:

1. Excess Grout. For most tile surfaces, grout won’t stick and cracks off over time. For porcelain surfaces, use a window scraper or a chisel VERY carefully. It’s more difficult to remove once dry, so wipe well into the grout joints.
2. Grout Haze. There will be a haze. However, if you’ve generously wiped the tiles after grouting, it should be minimal. I haven’t found haze cleaner to be necessary for cement-based grout, (as long as I didn’t have a lot of excess grout). I generally only recommend it for epoxy grout. Wait 24-48 hours after grouting to remove the haze with water. It will take several passes to remove it all.
3. Not pushing the grout in to the crevice. Always swoop the rubber grout float in multiple directions and press the grout into the lines evenly.
4. Grout Shrinkage and Cracking. Products have mostly conquered this problem, but it’s not uncommon for unsanded grout to slightly shrink into the lines. This is typically a result of too much water in the mix or inadequate curing time. It’s important to follow manufacturer guidelines and ensure proper curing to minimize the chance of this occurring.
5. Working yourself into a corner. The tile itself is dry and should not move. While I don’t recommend walking on the tile as normal, it’s fine to lightly tip-toe over the tile if necessary.
6. Mold and mildew growth. If you start demo on any project and find mold, don’t go any further. It’s time to call in the professionals!