How to Regrout Tile Floors and Backsplashes

Grout is the unsung hero of your tile surfaces, but it eventually falls victim to moisture, settling, and simple age. When you notice hairline cracks or loose material crumbling into your sink or onto your floor, it is time for a refresh. Leaving damaged grout exposed invites water behind your tiles, which can lead to mold or structural damage. Regrouting is a transformative project that makes old tile look brand new without the massive cost of a full demolition. Success lies in your patience during the removal phase and your attention to detail during the cleanup. Done well, your new grout lines will be uniform, clean, and sealed tight against the inevitable grime of daily life.

  1. Cut out the old grout. Use a grout removal tool or an oscillating multi-tool with a grout blade to cut out the old material. Aim to remove at least two-thirds of the depth of the old grout to ensure a solid bond for the new application.
  2. Purge dust and debris. Use a shop vacuum to pull every loose particle out of the open grout lines. Wipe the area down with a damp sponge or a mixture of vinegar and water to remove dust and lingering mold spores.
  3. Mix to perfect thickness. Follow the manufacturer's ratio on the bag, mixing only a small batch at a time to prevent it from hardening before you finish. Aim for a consistency that resembles smooth, thick peanut butter.
  4. Pack the joints tight. Hold a rubber grout float at a 45-degree angle and press the grout firmly into the joints. Work in diagonal strokes across the tiles to ensure you fill the gaps completely without scooping material back out.
  5. Wipe clean with precision. Wait about 15 to 30 minutes until the grout feels firm to the touch, then use a damp sponge to wipe the excess grout off the tile faces. Rinse your sponge frequently to keep the surface clean.
  6. Buff away the haze. After the grout dries to a light haze, buff the tile surfaces with a dry microfiber cloth. Avoid getting the grout lines wet for at least 24 to 48 hours while the material cures.