How to Re-Seal Your Shower (Step by Step)

✍️ Peter Kim, EIJ Construction📅 June 8, 2025⏱ 8 min read

Mouldy, cracked, or discoloured silicone is one of the most common home maintenance issues in Queensland. The good news? If you're reasonably handy, you can replace shower silicone yourself in a day — saving hundreds on a call-out fee. Here's exactly how to do it.

What You'll Need

Silicone remover gel or blade scraper, isopropyl alcohol (IPA), bathroom-grade silicone (sanitary silicone, not general purpose), a caulking gun, masking tape, a smoothing tool or your finger, and rubber gloves.

Step 1: Remove All Old Silicone

Apply silicone remover gel and leave for 2–3 hours. Use a blade scraper (be careful not to scratch tiles) to lift the old silicone. Remove every trace — new silicone won't bond over old. This step is where most DIY jobs fail.

Step 2: Clean and Dry Thoroughly

Wipe all joints with isopropyl alcohol. This removes soap residue, oils, and mould spores that prevent bonding. The joint must be completely dry before applying new silicone — ideally leave overnight.

Step 3: Apply Masking Tape

Apply masking tape along both sides of each joint, leaving a 4–6mm gap. This gives you clean, straight lines even if your application isn't perfectly even. Worth the extra 15 minutes.

Step 4: Apply Silicone

Cut the nozzle at 45° to match your joint width. Apply consistent pressure in one smooth, continuous bead. Don't stop and start — it creates lumps. Work one joint at a time from one end to the other.

Step 5: Smooth and Remove Tape

Dip your finger in water or use a silicone smoothing tool. Press firmly along the joint in one smooth pass. Immediately remove the masking tape while the silicone is still wet. Leave 24 hours before using the shower.

When to Call a Professional

If there's mould growing behind the tiles (you'll see discolouration through grout), structural movement causing repeat cracking, or waterproofing failure (water pooling under tiles) — call a licensed tradie. DIY silicone won't fix underlying waterproofing issues.

💡 Expert Tips from EIJ Construction

→Always buy sanitary/bathroom-grade silicone — not the cheap general-purpose variety
→Mould-resistant silicone is worth the extra $5 in Queensland's humid climate
→Don't rush drying time — silicone needs 24hrs minimum, 48hrs in humid conditions
→If you see water damage or soft tiles, stop and call a licensed waterproofing tradie

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Written by Peter Kim

QBCC-licensed waterproofing specialist & founder of EIJ Construction. Gold Coast · Sunshine Coast · SEQ.

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