Cleaning Bathroom Grout
Bathroom grout is porous, making it the most stain-retentive surface in the bathroom and the one that most visibly shows age and neglect. In Ontario homes — where bathrooms are used year-round without the extended ventilation that warmer climates allow — grout mould and staining is almost universal in units older than a few years. The right products make the difference between effective cleaning and a frustrating hour of scrubbing that changes nothing.
What Works
- Oxygen bleach (OxiClean, sodium percarbonate): The best option for most grout staining. Mix per instructions, apply to grout lines, leave 15–30 minutes, scrub with a stiff grout brush, rinse. Safe for coloured grout (unlike chlorine bleach)
- Baking soda paste + hydrogen peroxide: Mix to a thick paste, apply to grout, leave 10 minutes, scrub. Effective on moderate staining
- Chlorine bleach (undiluted): Most effective on mould in white grout. Apply with an old toothbrush, leave 10 minutes, scrub, rinse thoroughly. Not safe for coloured or natural stone grout
The Grout Brush
An electric grout brush (available at Canadian Tire for around $30) dramatically reduces cleaning time and effort. For manual cleaning, a stiff-bristle toothbrush or dedicated grout brush gets into the grout line profile that wider brushes miss.
After Cleaning: Sealing
Clean grout should be sealed with a penetrating grout sealer (spray-on, available at Home Hardware and Home Depot). Sealing closes the pores that allow staining — a sealed grout line resists mould and discolouration dramatically better than unsealed grout. Reapply annually.
Preventing Future Staining
Run the bathroom exhaust fan during and for 15–20 minutes after every shower. Mould growth in Ontario bathrooms is almost entirely a ventilation problem — grout doesn't stain in a dry bathroom.