How to clean grout in bathroom tiles
Step-by-step methods and the best tools for great results.
Updated Oct 18, 2026 · 6 min read
Apply a thick paste of 3 parts baking soda to 1 part hydrogen peroxide (or an oxygenated grout gel) along the grout lines, let dwell for 10 minutes, agitate with a stiff V-bristle nylon grout brush, rinse thoroughly with warm water, and dry with a microfiber towel.
Before You Start: Surface & Safety Check
- •Avoid wire or steel bristles on tile grout—metal scratches surrounding glaze and leaves rust marks when wet.
- •Skip vinegar on unsealed cement grout; repeated acid exposure slowly dissolves calcium carbonate in the mortar.
What You'll Need
Step-by-Step Instructions
Flush Loose Dust and Pre-Wet Grout Pores
Vacuum dry bathroom floor tile first, then mist the grout lines with warm water. Pre-wetting stops porous cement from sucking dirty wash water deeper into the joint.
Apply Oxygen-Active Paste and Dwell 10 Minutes
Stir 1/2 cup baking soda, 1/4 cup hydrogen peroxide, and 1 teaspoon dish soap into a frosting-like paste. Spread along grout joints and wait 10 minutes for micro-bubbles to loosen embedded soap scum.
Scrub Along the Joint Line with Nylon Bristles
Use a V-shaped grout brush (or the corner cone head on a spin scrubber at 300 RPM) in short strokes parallel to the grout line.
Rinse & Wipe Dry—Then Seal After 24 Hours
Rinse with clean warm water and immediately wipe dry with a microfiber cloth so dissolved dirt cannot settle back into the joints. Once dry for 24 hours, apply a penetrating grout sealer.
Recommended Tools for This Job
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Common Questions
How often should bathroom tile grout be sealed?
Cement-based shower grout should be resealed once every 12 months. Test by dropping a bead of water onto dry grout—if it darkens the grout within 60 seconds instead of beading up, it is time to reseal.