Epoxy grout and silicone do different jobs
Grout fills the gaps between tiles. For shower regrouting, we use Mapei Kerapoxy epoxy grout because it is non-porous and highly resistant to water, staining and mould. Silicone is an elastic sealant for junctions where surfaces can move slightly. Rigid grout can crack there, so it should not be used instead of silicone.
| Feature | Epoxy grout | Silicone sealant |
|---|---|---|
| Main job | Fills joints between tiles | Seals flexible corners and junctions |
| Best locations | Wall and floor tile joints away from changes of direction | Wall-to-wall and wall-to-floor corners, fixtures and screen edges |
| Movement | Hard, durable finish; not intended for movement joints | Flexible to accommodate small movement |
| Water resistance | Non-porous grout that resists water and staining | Forms a flexible surface seal when correctly installed |
| Typical failure | Cracking, missing joints or worn grout needs assessment | Splitting, lifting, shrinking, mould or loss of adhesion |
| Replacement approach | Old grout is removed before epoxy regrouting | Old silicone is cut out before new silicone is applied |
The tiled field and corners are separate details. Silicone over damaged grout will not rebuild missing tile joints. Regrouting without renewing failed corner silicone can leave a surface entry point for water.
Where silicone must be used (corners, wall-to-floor, screen, taps)
Silicone belongs at changes of plane and around penetrations, not across every tile joint. The old material needs complete removal and joint preparation before replacement; a new bead over loose, dirty or mouldy silicone is unlikely to bond soundly.
- Vertical internal corners where one tiled wall meets another.
- The wall-to-floor junction around the shower base or tiled floor.
- Shower-screen edges where the screen or channel meets the tiled wall or floor, where applicable.
- Around taps, mixers and other pipe penetrations after checking the fitting is secure.
- Other movement joints or junctions identified during inspection.
The detail depends on the shower layout. Water escaping around a screen may be a screen, drainage or installation issue rather than a silicone problem. Open joints or water getting behind a fitting should be assessed first.
Why silicone is a maintenance item
Silicone is exposed to soap residue, cleaning products, moisture and regular movement. It can lose adhesion, shrink, split or become difficult to clean. Not every discoloured bead is leaking, but it should be inspected.
Use a pH-neutral bathroom cleaner and a soft cloth or brush. Avoid abrasive pads, acids and aggressive scraping. Surface mould may improve with careful cleaning, but mould within the silicone or sealant that has detached generally needs removal and replacement rather than a coating on top.
Signs your silicone has failed
Check the edges as well as the colour. A continuous, well-adhered bead should not have gaps for water to travel behind it. Check for the following signs, especially if there is dampness outside the shower.
- Cracks, holes or missing sections in a corner or wall-to-floor joint.
- Silicone lifting away from the tile, shower base, screen channel or fitting.
- Dark mould embedded beneath the surface that remains after gentle cleaning.
- A bead that has shrunk, become brittle or has gaps at its ends.
- Peeling paint, swollen skirting, damp smells or staining near the shower.
- Water escaping at a shower-screen edge during normal use.
Surface repairs cannot confirm that the waterproof membrane behind tiles is intact, and they do not repair a leaking pipe. Dampness when the shower has not been used, or an unexplained increase in the water bill, can point to plumbing and should be checked by a plumber first.
How much does silicone replacement cost?
Shower silicone replacement starts from $450 + GST. Cost depends on the layout, the amount of old sealant to remove, joint condition and whether epoxy regrouting is also needed. A photo quote can help establish whether resealing is the right scope.
| Service | From price |
|---|---|
| Shower silicone replacement | $450 + GST |
For silicone-only work, see Shower Resealing Melbourne. Where tile joints have failed too, shower regrouting may be the appropriate repair. The condition of the tiles, grout, silicone, screen and visible damage determines the scope.
Frequently asked questions
Can I use silicone instead of grout in my shower?
No. Silicone is for flexible corners, junctions and penetrations. It does not replace grout between tiles across the wall or floor.
Do I need both epoxy grout and new silicone?
Often, yes. Epoxy grout repairs joints between tiles, while new silicone seals corners and movement joints. Addressing only one can leave the other as a surface entry point for water.
Will replacing silicone fix my leaking shower?
It can help when water is entering through failed silicone at corners, the shower base, the screen or fittings. It will not fix a failed waterproof membrane, loose tiles, drainage problems or a plumbing leak, so the cause should be assessed first.
Can new silicone be applied over old silicone?
No. Old silicone should be cut out completely, then the joint cleaned and prepared before replacement. New silicone over loose, contaminated or mouldy material may not adhere properly.
How much does shower silicone replacement cost in Melbourne?
Shower silicone replacement starts from $450 + GST. Final cost depends on the shower size and layout, old sealant condition and preparation required.
Send photos for a fixed quote
Send a photo of the whole shower or balcony and a close-up of the grout. We assess the visible condition and explain whether regrouting and resealing are suitable.