How to Re-Grout Bathroom Tile in a Weekend

Dirty, cracked, or stained grout is one of the most common complaints about older bathrooms, and one of the easiest to fix yourself. Re-grouting a standard shower or tub surround takes a weekend and about $100 in materials.

What you'll need

• Grout saw or oscillating tool with grout removal blade
• Grout (sanded for joints wider than 1/8", unsanded for narrower)
• Grout float
• Large sponge and two buckets
• Grout sealer
• Safety glasses and dust mask
• Shop vacuum

Step 1: Remove old grout

This is the hard part. A manual grout saw works but takes forever — invest in an oscillating tool with a grout removal blade. Work carefully to avoid scratching the tile surface. You only need to remove grout to a depth of about 1/4" — you don't need to go all the way down to the substrate. Vacuum out all dust and debris when done.

Step 2: Mix grout to the right consistency

Mix grout according to package instructions to a peanut butter consistency, not too wet, not too stiff. Let it slake (rest) for 10 minutes after mixing, then stir again. Mix only as much as you can use in 20–30 minutes.

Step 3: Apply grout with a float

Hold the float at a 45-degree angle and press grout firmly into the joints, working diagonally across the tile. Make sure joints are completely filled. Remove excess by sweeping the float diagonally across the tile surface.

Step 4: Clean — this is where most people go wrong

Wait 15–20 minutes after grouting for the grout to start setting (it will look slightly hazy on the tile surface). Then wring out a large sponge until barely damp and wipe in circular motions. Rinse the sponge frequently. Don't use too much water — it weakens the grout. Clean grout haze with a dry cloth once the grout has cured (24 hours).

Step 5: Caulk the corners

Never grout the corners where walls meet or where tile meets the tub — these joints need to flex. Use silicone caulk in a color matching your grout. Grout in corners cracks within months.

Step 6: Seal the grout

After 72 hours, apply grout sealer to all grout lines. This step is critical and most homeowners skip it. Sealer prevents staining and makes cleaning much easier. Reapply annually.

When to call a professional instead

Re-grouting is DIY-friendly if the tile is solid and the substrate is dry. Call a contractor if: tiles are loose, there are soft spots, you see mold behind existing grout, or the original waterproofing has failed. These are signs of a bigger problem that a grout job won't fix.