How do i reseal a leaking shower without re tiling? (2026)
Quick Answer
If the leak is coming through cracked or failed sealant at the edges of the shower, around the tray, or at corners, you can often stop it without re-tiling by removing all loose old silicone, thoroughly drying the area, and resealing with a bathroom-grade sanitary silicone. This only works if the waterproofing behind the tiles is still sound and the leak is not from plumbing, grout failure across large areas, movement, or a damaged shower tray. If water is getting into walls or floors despite fresh sealant, the problem is likely deeper than the visible joints.
Overview
A leaking shower does not always mean you need to strip tiles off the wall. Many shower leaks happen because the flexible seal at corners, where walls meet the tray, or around screens and fittings has failed. Silicone eventually loses adhesion, splits with movement, or allows water behind it if gaps were badly prepared in the first place. In those cases, careful resealing can be a practical repair. The key is diagnosis before you start. If the leak only appears when the shower is used and you can see cracked, mouldy, lifting or missing sealant, resealing is worth trying. If the leak happens even when the shower is not running, check for a plumbing leak first. If tiles are loose, grout is crumbling over large areas, the shower tray moves, or the wall lining feels soft, resealing alone is unlikely to solve it because the waterproof layer behind the surface may already be compromised. A successful repair depends on removing all failed sealant, getting the joint completely clean and dry, and applying the correct sanitary silicone in one continuous bead. Trying to patch over old silicone usually fails quickly. If you are unsure whether the water is getting past the finish layer or through a concealed pipe, stop and get it checked before more hidden damage builds up.
Who this is for
Homeowners or tenants with permission who have a tiled shower leaking at visible joints or edges and want to try a surface-level repair before considering more disruptive work.
What you’ll need
- Bathroom or sanitary silicone suitable for wet areas
- Caulking gun if the sealant cartridge requires one
- Sealant remover or a plastic scraper
- Utility knife or sealant removal tool used carefully
- Mould cleaner or bathroom cleaner
- Clean cloths or paper towels
- Masking tape
- Disposable gloves
- Good ventilation
- Manufacturer instructions for the sealant you choose
Before you start
Work out where the leak is really coming from. Look for failed silicone at internal corners, where tiles meet the shower tray or floor, around the screen frame, and around penetrations such as taps or mixers. Check whether the leak only happens during showering, whether grout is cracked, whether the tray or screen moves when pressed, and whether there are signs of swollen skirting, stained ceilings below, or soft wall linings. Do not rely on grout as a waterproof barrier; the waterproofing should be behind the tiles. If there is significant movement, structural damage, a leaking waste, or persistent damp behind the shower, resealing the visible joints may not be enough.
Step-by-step
- 1
Confirm the leak path
Dry the shower fully, then inspect all corners, tray-to-tile joints, screen edges and penetrations. Look for gaps, splits, peeling silicone, mildew under the bead, loose trim or missing grout. If needed, use the shower briefly and watch where water tracks and escapes.
Why: You need to fix the actual entry point. Resealing random areas wastes time if the leak is from a waste fitting, pipe, or failed waterproofing behind the tiles.
- 2
Remove the old sealant completely
Cut and lift out the failed silicone from the affected joints. Remove every trace you can from both sides of the joint using a remover product or scraper suitable for the surface. Do not apply new silicone over old silicone.
Why: Fresh silicone will not bond reliably to contaminated or loose old sealant, and hidden mould or soap residue under the old bead can create a leak path.
- 3
Clean and treat the joint
Clean away soap scum, body oils, dust and any mould staining. Follow the cleaner instructions and wipe the area until the surfaces are clean. Let the area dry fully afterwards.
Why: Sealant sticks poorly to dirty or damp surfaces. Mould and residue can also stop the bead from sealing tightly at the edges.
- 4
Dry the area thoroughly
Leave the shower unused until the joint is completely dry. Ventilate the room well and check the product instructions before sealing. If water has been trapped in the joint, give it extra drying time.
Why: Moisture trapped behind the bead can stop adhesion and can lead to early failure, mould growth or a continued leak.
- 5
Mask and apply new sanitary silicone
Run masking tape along both sides of the joint if you want a neat finish. Apply a continuous bead of bathroom-grade sanitary silicone along each joint that was opened up, making sure the sealant bridges the joint and contacts both sides evenly. Avoid stopping and starting if possible.
Why: A continuous, well-bonded bead forms a flexible waterproof barrier that can tolerate normal movement between surfaces.
- 6
Tool the bead and remove tape
Smooth the bead according to the product instructions so it is pressed firmly into the joint and has a tidy finish. Remove masking tape carefully while the sealant is still workable.
Why: Tooling helps eliminate voids and improves contact with the surfaces, which is what actually makes the seal watertight.
- 7
Let it cure fully before using the shower
Keep the shower completely dry until the sealant has cured for the period stated on the product label. Do not splash, wipe, or test it early.
Why: Using the shower too soon can wash out or weaken the new bead before it has developed full adhesion and water resistance.
- 8
Test carefully and monitor
Once fully cured, run the shower and check the repaired joints and the adjacent room, floor below, or access panel area if you have one. Keep an eye on it over the next few uses.
Why: A controlled test confirms whether the visible joint was the true cause or whether there is another hidden issue still allowing water through.
Why this works
Resealing works when the leak is caused by failed flexible joints rather than failed tiles or plumbing. Silicone creates a waterproof, flexible bridge where different surfaces meet and move slightly in use. If the original bead has split, debonded or left gaps, water can track behind the finish and escape into surrounding walls or floors.
Common mistakes to avoid
- Applying new silicone over old silicone or soap residue
- Using the shower before the sealant has fully cured
- Assuming grout is a waterproof substitute for sealant
- Ignoring movement in the tray, screen or wall that will reopen the joint
- Trying to seal over a leak caused by a waste fitting, pipe or failed waterproofing membrane
Troubleshooting
New sealant peels away within days or weeks
Remove it and start again after more thorough cleaning and drying. Check that the product is suitable for wet bathroom joints and that all old silicone was removed.
The leak continues even though the joint looks well sealed
Check the shower waste, tap or mixer penetrations, screen fixings, tray movement, cracked grout over a wide area, and signs of failed waterproofing behind the tiles. At that point, a professional assessment is sensible.
Mould keeps appearing under the silicone
Remove the affected bead fully, clean the area properly, improve ventilation, and make sure the area was dry before resealing. Persistent regrowth can mean moisture is still trapped behind the surface.
Water leaks at the screen frame or wall channel
Inspect the manufacturer’s sealing arrangement first. Some shower screens are only sealed on specific sides, and sealing the wrong side can trap water instead of directing it back into the shower.
Compare your options
Reseal visible joints only
Best for: Leaks clearly caused by split or missing silicone at corners, tray edges or around the screen
Pros: Least disruptive, relatively low cost, no need to remove tiles if the substrate is sound
Cons: Will not solve hidden waterproofing, plumbing or movement problems
Regrout and reseal
Best for: Showers with minor local grout deterioration as well as failed edge sealant
Pros: Improves appearance and can reduce surface water entry points
Cons: Grout is not the waterproof layer; this can still fail if the membrane or backing is compromised
Partial rebuild or professional shower repair system
Best for: Persistent leaks, substrate damage, loose tiles or likely waterproofing failure without full bathroom renovation
Pros: Addresses deeper causes that sealant alone cannot
Cons: More invasive and costly, and may still require opening up parts of the shower
| Option | Best for | Pros | Cons |
|---|---|---|---|
| Reseal visible joints only | Leaks clearly caused by split or missing silicone at corners, tray edges or around the screen | Least disruptive, relatively low cost, no need to remove tiles if the substrate is sound | Will not solve hidden waterproofing, plumbing or movement problems |
| Regrout and reseal | Showers with minor local grout deterioration as well as failed edge sealant | Improves appearance and can reduce surface water entry points | Grout is not the waterproof layer; this can still fail if the membrane or backing is compromised |
| Partial rebuild or professional shower repair system | Persistent leaks, substrate damage, loose tiles or likely waterproofing failure without full bathroom renovation | Addresses deeper causes that sealant alone cannot | More invasive and costly, and may still require opening up parts of the shower |
Alternatives
- Replace failed grout in small localised areas, then reseal movement joints correctly
- Reseal or refit the shower screen if the leak is around the frame rather than the tiled corner
- Have the waste connection, mixer penetrations or tray support checked if the leak source is uncertain
Pro tips
- Take photos before removing sealant so you remember exactly which joints were originally sealed
- Use a sanitary bathroom silicone designed for wet areas rather than a general-purpose sealant
- Work on one section at a time if the shower has many joints to avoid missing areas
- If the shower tray flexes underfoot, fix the movement problem or the new seal may split again
Safety notes
- Ventilate the room when using cleaners, mould treatments or sealant removers
- Use blades carefully to avoid scratching trays, tiles and glass, and to avoid cutting yourself
- Keep cleaning products and sealants away from children and pets
- Do not mix cleaning chemicals unless the manufacturer instructions explicitly say it is safe
Legal & regulatory notes
Bathroom waterproofing and plumbing work can be regulated and may need to meet local building requirements. Surface resealing is usually simple maintenance, but if the leak involves concealed plumbing, waterproofing replacement or structural repair, check local rules and use appropriately qualified tradespeople where required.
What this guide does not cover: This guide covers surface-level resealing only. It does not cover replacing waterproof membranes, repairing concealed plumbing, rebuilding shower trays, or diagnosing structural rot and extensive substrate failure.
Cost considerations
Resealing is usually far cheaper than re-tiling or rebuilding a shower, but repeated DIY patching can become false economy if hidden water damage is developing. The real cost risk is delaying a proper diagnosis when the leak is not actually from the visible joints.
Prefer to hire a professional?
If this job is beyond a confident DIY — or the work needs to be done by a licensed professional — you can find a verified plumber through these directories of real, verified trade businesses. Compare local tradespeople, read their details and request quotes before you commit.
Frequently asked questions
Can I just put new silicone over the old bead?+
Usually no. New silicone does not bond reliably to old contaminated silicone, and any trapped mould or gaps underneath can keep leaking. Full removal gives a much better chance of a lasting repair.
Will regrouting stop a shower leak?+
Not necessarily. Grout is not the primary waterproof barrier in a tiled shower. Regrouting can help tidy the surface and reduce water entry, but if the leak is from failed movement joints, plumbing or waterproofing behind the tiles, grout alone will not solve it.
How do I know if the waterproofing behind the tiles has failed?+
Warning signs include loose tiles, soft wall linings, ongoing damp smells, swelling in adjacent surfaces, leaks that continue despite intact sealant, or widespread cracking and movement. Those signs usually need professional investigation.
Do I need a plumber or a tiler?+
If the issue is only failed sealant, many homeowners can reseal it themselves. If the leak may be from the waste, pipework or mixer penetrations, call a plumber. If tiles are loose or waterproofing may have failed, you may need a bathroom repair specialist or builder as well.
Can a shower screen be sealed on both sides?+
Not always. Some screen systems are designed to drain internally and should only be sealed on certain faces. Check the screen manufacturer instructions before adding sealant, or you can trap water and worsen leaks.
Sources & references
Guidance on this page is traced to documented sources. Last checked 25 September 2026.
- Building Performance New Zealand · government
Supports general New Zealand building and maintenance context, including the importance of compliant wet-area construction and building envelope performance.
- MBIE New Zealand Building Code clauses · government
Supports the point that bathroom waterproofing and moisture control are regulated building matters rather than cosmetic issues only.
- Bostik New Zealand · manufacturer
Supports using a bathroom or sanitary silicone suitable for wet areas and following the specific product instructions for preparation and curing.
- Selleys New Zealand · manufacturer
Supports the need to remove old sealant, prepare surfaces properly, and follow manufacturer directions for bathroom sealants.
The basic repair method changes slowly, but exact product preparation and curing requirements vary by manufacturer and should always be checked on the label.