How to replace mould on shower silicone
Mouldy silicone around your shower can make your bathroom look tired, dirty, and even unhealthy. But here’s the good news: replacing mouldy silicone is a quick and cost-effective way to make your shower look 10 years newer—without a full renovation.
Whether you’re a DIY enthusiast or just trying to keep your home clean and healthy, this guide will show you how to replace mouldy silicone in your shower, step by step.
Why Replacing Mouldy Silicone Matters
Old, mouldy, or cracked silicone isn’t just an eyesore, it can be a health hazard too. Mould thrives in damp environments like bathrooms, especially around poorly sealed edges. If left untreated, it can cause respiratory issues, worsen allergies, and damage your walls and tiles over time.
Fun fact: Simply replacing your shower sealant can instantly boost hygiene, prevent leaks, and give your bathroom a fresher, cleaner appearance.
Expert Shower Repairs and
Installations Across New Zealand
When you need a leaky shower fixed, a shower door replaced, or complete installation. Our friendly, reliable, and no-nonsense team will be on the job and will provide quality services each and every time.
What Causes Mould to Grow in Shower Silicone?
High moisture levels and poor ventilation
Low-quality or expired silicone
Improper application or cracked seals
Not allowing enough time to cure
If you notice black stains, crumbling sealant, or a persistent damp smell, it’s time to take action.
Signs It’s Time to Replace Your Shower Silicone
✅ Black or brown mould stains
✅ Peeling, cracked, or shrunken silicone
✅ Water seeping through corners or edges
✅ Musty smell that won’t go away
Don’t wait for a leak or costly water damage, replacing the sealant now saves trouble later.
What You’ll Need to Replace Mouldy Silicone
Before you get started, gather these items:
Silicone remover or sharp utility knife
Plastic scraper or putty knife
Rubbing alcohol or white vinegar
Anti-mould silicone sealant (bathroom grade)
Caulking gun
Paper towels or microfiber cloth
Masking tape (optional for cleaner lines)
Pro tip: Use high-quality, anti-mould silicone designed specifically for wet areas like showers.
Step-by-Step: How to Replace Mouldy Silicone in Your Shower
1. Remove the Old Silicone
Use a silicone remover or a utility knife to carefully cut and lift the old sealant. Work slowly to avoid damaging your tiles or grout.
Tip: A plastic scraper helps remove the stubborn bits without scratching.
2. Clean the Area Thoroughly
Use rubbing alcohol or white vinegar to clean away any remaining residue and kill hidden mould spores. Dry the area completely with a clean towel.
3. Apply Masking Tape (Optional)
For straight, professional-looking lines, apply masking tape along both sides of the joint you’re sealing.
4. Apply New Silicone Sealant
Cut the tip of the silicone tube at a 45° angle. Load it into a caulking gun and apply a steady, even bead along the joint. Keep your hand moving smoothly for best results.
5. Smooth the Silicone Bead
Use your finger or a silicone finishing tool (dipped in soapy water) to gently smooth the sealant. This helps it adhere better and creates a neat finish.
6. Remove Masking Tape & Let It Cure
Carefully peel off the masking tape before the silicone dries. Let the sealant cure undisturbed for at least 24 hours—longer in colder or more humid conditions.
DIY or Professional? When to Call in the Experts
Replacing silicone is a simple job for many homeowners but not always.
🛠️ Call a professional if:
- Mould has spread behind tiles
There’s visible water damage
The area is hard to access or seal properly. - You don’t have the tools or time
At Showerfix, we specialise in professional shower sealant replacement, ensuring a perfect finish with mould-resistant products that last.
How to Prevent Mould from Returning
✅ Ventilate your bathroom, open windows or use an extractor fan
✅ Wipe down your shower after use
✅ Use anti-mould sprays weekly
✅ Check your silicone every 6-12 months for signs of wear
Routine maintenance keeps your bathroom clean, fresh, and mould-free all year round.
FAQs: Shower Silicone Replacement
Q1: How often should I replace shower silicone?
Every 2-5 years, depending on conditions. Check annually for mould or cracking.
Q2: Can I apply new silicone over old silicone?
No. Old silicone must be completely removed or the new layer won’t adhere properly.
Q3: What type of silicone should I use in a bathroom?
Always use anti-mould, waterproof silicone designed for bathrooms and wet areas.
Q4: How long does bathroom silicone take to dry?
Most products require 24 hours to fully cure, but check the label for specifics.
Q5: Is black mould in shower silicone dangerous?
It can be especially for people with asthma or allergies. Always remove it promptly.
Replacing mouldy silicone is one small job that makes a huge impact. Your shower will look cleaner, feel fresher, and be safer for your family.
If DIY isn’t your thing or you want guaranteed results Showerfix is here to help.
Expert Shower Repairs and
Installations Across New Zealand
When you need a leaky shower fixed, a shower door replaced, or complete installation. Our friendly, reliable, and no-nonsense team will be on the job and will provide quality services each and every time.