Mould on your ceiling isn’t just an eyesore—it’s a potential health risk and a sign that moisture problems are lurking in your home. At HydroWorks Plumbing, we’ve helped countless San Francisco homeowners address mould issues caused by leaks, poor ventilation, and hidden plumbing problems. If you’re noticing dark spots, discolouration, or that musty smell above your head, here are proven methods to remove mould from ceilings and keep it from coming back.
Step 1: Identify the Cause of the Mould
Before you reach for cleaning supplies, it’s crucial to understand why mould is growing on your ceiling. Common causes include:
Leaky plumbing or roof allowing water to seep in.
High humidity in bathrooms or kitchens with poor ventilation.
Condensation build-up from temperature differences.
Without fixing the source, mould will keep returning no matter how many times you clean it.
Step 2: Protect Yourself First
Mould releases spores that can trigger allergies and respiratory issues. Always wear:
Gloves
Safety goggles
A face mask (N95 if possible)
And make sure the area is well-ventilated by opening windows and doors.
Step 3: Clean with Proven Mould-Removal Solutions
Option 1: White Vinegar Solution
Mix white vinegar with water (1:1 ratio).
Spray directly on the mouldy area.
Let it sit for at least 1 hour.
Scrub gently with a sponge or soft brush, then wipe clean.
Option 2: Baking Soda Paste
Combine baking soda with water to form a thick paste.
Apply to the affected ceiling area.
Scrub lightly, then rinse with water.
This works best for lighter mould stains.
Option 3: Commercial Mould Removers
Available at most hardware stores.
Contain stronger chemicals like hydrogen peroxide or fungicides.
Follow the manufacturer’s instructions carefully.
⚠️ Avoid using bleach on painted ceilings—it often discolours the paint and doesn’t penetrate porous surfaces, meaning mould may return.
Step 4: Repair and Prevent Future Mould Growth
Cleaning is only half the battle. To keep your ceiling mould-free:
Fix leaks immediately (roof, plumbing, or ceiling cracks).
Improve ventilation with exhaust fans