How to Remove & Replace Mouldy Shower Silicone (Easy Way to a Professional Finish), by Renovation Dan on YouTube. 7 min 15 s.
- Video length
- 7 min 15 s
- Time to do it
- 2 hours plus 24 hours curing
- Difficulty
- Easy
- Steps
- 10
What you need
Steps
Cut along both edges of the old silicone with a sharp knife, then pull the bead away in one piece where you can.
Scrape off stubborn residue and apply silicone remover to any patches that will not lift, following the product label.
Clean the whole joint with a mould treatment or bleach-based cleaner, then rinse and let the gap dry completely.
Check the gap is fully dry before sealing. Trapped moisture is what feeds new mould, so give it time.
Choose a sanitary grade silicone made for bathrooms, as it resists mould better than standard sealant.
Run masking tape along both sides of the joint, leaving a strip of bare surface the width of your finished bead.
Cut the nozzle at an angle to the bead width, load the tube in the gun and push a steady bead along the joint.
Smooth the bead with a silicone profiling tool or a wet finger, keeping one continuous pass.
Peel the masking tape off straight away while the silicone is still wet, pulling it back on itself for a crisp edge.
Leave the silicone to cure for the time on the tube, usually around 24 hours, before using the shower.
Tips and common mistakes
Never seal over damp silicone or a wet gap, as the new bead will peel and mould will return.
Use sanitary grade silicone rather than general purpose sealant for shower joints.
Remove the masking tape before the silicone skins over, or it will tear the edge.
Keep a damp cloth handy to wipe tools and fingers between passes.
Questions
Can I just clean the black mould off instead of replacing the silicone?
Surface cleaning rarely fixes it because mould grows under and inside the sealant. If the silicone is black through the bead or lifting at the edges, cut it out and replace it.
How long before I can use the shower again?
Wait for the full cure time printed on the tube, often around 24 hours. Using it sooner can break the seal and let water back in.
What silicone should I buy?
Pick a sanitary or bathroom grade silicone labelled mould resistant. It costs a little more but lasts longer in wet areas.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
