How do I clean bathroom tile grout?

Cleaning bathroom tile grout is something most homeowners can tackle themselves with the right approach and a bit of elbow grease.

Start with the simplest method first. Mix baking soda with water to form a thick paste, apply it to the grout lines, then spray with white vinegar and let it fizz for a few minutes. Scrub with a stiff-bristled grout brush (an old toothbrush works for small areas) and rinse thoroughly. This handles light to moderate staining without harsh chemicals.

For tougher stains, oxygen bleach is your best friend. Products like OxiClean mixed with warm water are effective and safer than chlorine bleach, which can degrade grout over time and discolour coloured grout. Apply the solution, let it sit for 10-15 minutes, scrub, and rinse well. Always ventilate the bathroom properly when using any cleaning product.

Avoid steam cleaners on older grout or grout that's already showing signs of cracking or crumbling — the heat and pressure can accelerate deterioration. Similarly, avoid acidic cleaners like vinegar on natural stone tile (marble, travertine, limestone), as acid etches the surface permanently.

Once your grout is clean, applying a grout sealer is one of the best things you can do. Sealer penetrates the grout and repels moisture and staining, making future cleaning much easier. In Ottawa's humid bathroom environments, resealing every 1-2 years is a good habit.

If your grout is deeply stained, cracked, or crumbling, cleaning won't solve the underlying problem — regrouting or recaulking becomes necessary. That's also a sign to check for water infiltration behind the tile, which is a more serious issue. If you're noticing loose tiles, soft spots, or persistent mould that keeps returning, it's worth having a contractor assess whether your waterproofing is intact.