> [!tip] Quick answer: Spray mouldy grout and silicone with undiluted white vinegar, let it sit for an hour, then scrub with a stiff brush. For black or stubborn mould, use a paste of baking soda and hydrogen peroxide. Replace silicone caulking that mould has penetrated; cleaning won't reach it. ## How to clean shower mould in 2026 Shower mould is one of the most persistent bathroom problems, and one of the easiest to misdiagnose. Surface mould wipes off with vinegar and never comes back if you fix the moisture cause. Deep mould (the kind that's spread into silicone caulking or behind tiles) won't yield to any cleaning product and needs replacement. This guide covers both: how to kill and remove surface mould, and how to tell when the problem is beyond cleaning. ### What you should plan for - Active time: 15 minutes; total time 1 to 2 hours with soak time - Tools: Spray bottle, vinegar, baking soda, hydrogen peroxide, stiff brush - Cost: Under $15 for all supplies - Frequency: Monthly for prevention; immediately when mould appears - Safety: Ventilate fully; never mix vinegar with bleach or peroxide ## Step-by-step mould removal 1. Ventilate the bathroom. Open the window, turn on the exhaust fan. Mould spores release into the air during cleaning. 1. Spray undiluted white vinegar directly onto every mouldy area. Cover tile, grout, silicone caulking, and any visible spots. 1. Let it sit for one hour. Vinegar kills 80% of mould species on contact. 1. Scrub with a stiff brush. A grout brush or old toothbrush works for narrow lines. Use circular motions. 1. Rinse with warm water. Run the shower for 1 to 2 minutes to flush spores and residue. 1. Dry thoroughly. Squeegee walls, towel-dry corners. Run the fan another 30 minutes. ## When vinegar isn't enough: the peroxide paste For black mould, stubborn spots, or mould that's been growing for months: 1. Mix baking soda + 3% hydrogen peroxide into a thick paste (about 3:1 ratio). 1. Apply directly to mouldy areas with a toothbrush or small spatula. 1. Cover with plastic wrap to keep it moist (optional, more effective). 1. Let sit for 30 minutes to a few hours. 1. Scrub, rinse, and dry as above. For coloured grout, test on a hidden area first. Hydrogen peroxide can lighten old grout. ## What you'll need ## What kind of mould do you have ## When to replace instead of clean Silicone caulking. Once mould penetrates silicone, no cleaner reaches it. Remove the old caulking with a utility knife, clean the area, dry fully, and apply fresh mould-resistant silicone (DAP or GE Mould-Free, $10 to $15 at any Canadian hardware store). Cracked or missing grout. Mould thrives in cracks. Regrout the affected area before mould returns. Persistent mould that returns weekly. A bigger ventilation or moisture problem exists. Check that the exhaust fan vents outside (not into the attic), and run it for at least 30 minutes after every shower. ## Common mistakes 1. Mixing vinegar with bleach or peroxide. Creates toxic fumes. Use them in separate steps with full rinsing in between. 1. Using bleach on grout. Bleach lightens the mould but doesn't kill the roots. It also weakens grout over time. Vinegar and peroxide are better. 1. Skipping ventilation. Mould spores spread during cleaning. Always open the window and run the fan. 1. Cleaning without drying after. Mould grows back in 24 hours on wet surfaces. Squeegee and run the fan after every clean. 1. Painting over mould. Mould bleeds through paint within weeks. Always kill and remove first. ## Preventing mould long-term - Run the exhaust fan during AND 30 minutes after every shower - Squeegee walls after every shower (cuts moisture by 80%) - Wash shower curtains and liners monthly - Wipe down the grout weekly with vinegar spray - Keep the bathroom door open between showers to circulate air ## FAQs about cleaning shower mould Is shower mould dangerous? Can I use bleach instead of vinegar on shower mould? Why does mould keep coming back in the same spot? How do I clean mould from a shower curtain? Should I call a professional for shower mould?