best way to seal around a shower tray

you need a high-quality, flexible, and anti-fungal sealant. Strip completely using silicone removal gel and plastic scrapers avoid scratching trays..kill any mold using white spirit..must be bone dry before applying new Sealant so give it time dont rush

Thoroughly remove all old sealant and apply a high-quality, anti-mould sanitary silicone

Using plumber’s mait isn’t the right solution here — it’s not designed as a visible or long-term seal and will just fail again.
If the seal has failed badly, the best approach is to remove all the old silicone completely, clean and dry the area properly, then reseal using a good quality sanitary silicone.
Before resealing, it’s important to check why it failed. In most cases it’s due to movement in the tray or poor prep. If the tray has any flex, that needs sorted first (proper support underneath), otherwise any seal will keep cracking.
When resealing, fill the tray with a bit of water before applying the silicone — this helps account for movement and prevents it pulling away later. Then apply a clean bead of sanitary silicone and smooth it off.
If there’s significant movement or ongoing leaks behind, it may need lifting and re-bedding properly, but for most cases a proper strip out and reseal will solve it.

sanitary silicone with tray filled with water

No — plumber's mait is not the right repair for a failed shower tray seal.

The best solution is usually to remove all the old sealant completely, dry the area properly, fix any movement first, and then reseal with a high-quality sanitary silicone. Sanitary silicone is designed for wet areas and movement; silicone sealants are made to remain flexible and can accommodate joint movement, whereas plumber's mait is a bedding/sealing compound for fittings, not an exposed shower-tray perimeter seal.

The key point is this: if the tray is moving, new sealant alone may fail again. In that case, the tray or support beneath it needs checking first. If the tray is solid, then the normal repair is:

remove every trace of old silicone
clean and fully dry the joint
Check for loose tray, screen, or wall panel edges
Reseal neatly with mould-resistant sanitary silicone
Allow full cure before using the shower.
Manufacturers' installation guidance for shower wall/tray interfaces typically calls for flexible neutral-cure silicone sealant at the tray junction, not mait.

If you are worried about the surface, that is a fair concern. Some sealants can stain porous materials, so for natural stone or sensitive finishes, you need a non-staining / suitable sanitary sealant rather than just any generic product.

Plumber’s Mait wouldn’t be suitable for sealing around a shower tray, as it’s not designed for exposed joints or areas with regular water flow.

The best solution is to remove all the old sealant completely, clean and dry the area properly, and then reseal using a high-quality sanitary-grade silicone. It’s important to make sure the surface is free from mould, grease, and moisture before applying.

If there has been significant movement, I would also check that the shower tray is properly supported underneath, as movement can cause the seal to fail again. In some cases, re-bedding or reinforcing the tray may be needed.

Using a flexible, mould-resistant bathroom silicone will provide a long-lasting and watertight seal.

Don’t use Plumber’s Mait on a shower tray. The proper fix is:
• Remove all old silicone completely, clean/degrease and dry (mould remover if needed).
• If there’s movement, fix the cause first (tray not supported/loose frame) or it will fail again.
• Re-seal with a good sanitary neutral-cure silicone (anti-mould). Fill the tray with water first, then silicone, leave 24 hrs.
• If the gap is big, use backer rod then silicone (not grout).

If it’s “serious leaking”, suspect the waste/trap or tray movement—resealing alone may not cure it.

The best solution is to remove the failed seal completely and reseal the tray properly with a good-quality silicone.

Plumber’s Mait isn’t suitable for sealing shower trays — it never fully sets, attracts dirt, and won’t cope with constant water or movement. It’s intended for threaded plumbing joints, not exposed wet areas.

A good quality mastic. Remove and clean the existing sealant, then ensure both surfaces are dry and clean. Make sure that the mastic covers both surfaces.

Cut out and clean off all old silicone.
Ensure the tray is firmly supported (no flex).
Dry the area completely.
Apply a continuous bead of quality bathroom silicone between tray and tiles.
Leave at least 24 hours before use.

Remove ALL old sealant
Use a sharp blade + silicone remover
Get back to clean, dry surfaces
No residue — silicone will not bond otherwise

Shower trays expand and contract slightly, so the sealant needs to accommodate this. Plumbers’ mastic can be flexible, but good-quality sanitary silicone is usually better for long-term waterproofing and movement.

1.If the seal around a shower tray has failed and is leaking badly, the first and most important step is to remove all of the old sealant completely. Any new product applied over existing or contaminated sealant will fail again very quickly.
Once removed, the surfaces must be thoroughly cleaned and dried. This includes removing soap residue, mould, and any moisture. The joint should then be checked for movement or gaps, as excessive movement usually indicates that the shower tray is not fully supported underneath.
Plumber’s mait is not recommended for sealing around shower trays. It is not designed for constant water exposure and will not provide a long-term waterproof seal.
The best solution is to use a high-quality sanitary silicone sealant, specifically designed for bathrooms and wet areas. Where there is movement, a flexible, mould-resistant silicone should be used. The sealant should be applied neatly in one continuous bead and tooled properly to ensure full contact with both the tray and the wall tiles.
If movement is excessive or leaks persist, the tray may need to be re-seated or supported correctly before resealing. Done properly, this will provide a long-lasting, watertight finish.

2. Another option is to use a waterproof sealing tape (often referred to as “no more leaks” tape), but this is only effective if it is installed correctly.
For best results, the shower tray normally needs to be removed. The tape is designed to sit behind the tiles and overlap the tray, creating a hidden waterproof barrier. This means the tray is taken out, the tape is fixed to the wall and floor junction, and then the tray is refitted before the final silicone seal is applied.
Simply sticking this type of tape over the top of an existing tray without removing it is not a long-term solution and often fails.
In most cases, a properly supported tray sealed with high-quality sanitary silicone is sufficient. Waterproof tape is usually recommended where there has been previous leakage or where extra protection is required, but it involves more labour and cost due to removing and refitting the tray.

The Correct Solution: High?Quality Sanitary Silicone + Proper Prep
1. Remove ALL old silicone
• Cut it out with a sharp blade or silicone removal tool
• Clean the area with silicone remover or white spirit
• Make sure no residue is left — new silicone won’t bond to old silicone
2. Dry the area completely
If the tray has been leaking, moisture will be trapped behind the tiles.
Leave it to dry for several hours (or overnight if it was badly soaked).
3. Fill the bath/shower tray with weight
This is the step most people skip — and it’s why seals fail.
Shower trays and baths flex when someone stands in them.
If you seal it while empty, the silicone will tear the first time it moves.
Fill the tray with water (or stand in it) while applying the silicone.
This pre?loads the movement.
4. Use a top?quality sanitary silicone
Look for:
• 100% silicone
• Anti?mould / anti?fungal
• High flexibility (low modulus)
• Bathroom grade
Brands that perform well:
• Dow 785
• CT1 (expensive but excellent)
• Everbuild Forever White
5. Apply a smooth, continuous bead
• Mask the edges if you want a perfect line
• Apply a steady bead
• Tool it with a silicone tool or your finger dipped in soapy water
• Remove tape immediately
• Leave 24 hours before using the shower

If the seal has failed badly and you’re getting serious leaks, the first thing to understand is that sealant alone is rarely the root fix – it’s only the final waterproof barrier.

Do not use plumber’s mate around a shower tray. It never fully cures, attracts dirt, can break down plastics/acrylic, and will eventually fail again. It’s for compression joints, not exposed wet areas.

Don’t use Plumber’s Mait — it never cures, isn’t suitable for exposed wet joints, and can damage shower tray surfaces. The best solution is to remove all old sealant, thoroughly clean and dry the joint, then reseal using a high-quality sanitary-grade neutral-cure silicone designed for showers, which remains flexible to accommodate movement and resists mould. If the tray flexes, use a foam backer rod first and allow the silicone to cure fully (24–48 hours) before using the shower.

Remove all previous silicone, try and get the surface back to as close as possible to original and flat. Dry off the surface. Re-apply silicone, making sure you fill the gap fully. Remove excess silicone check for any gaps or holes. Leave to set for appropriate time and test.

The Best Solution: Full Resealing Process
Remove Old Sealant: Cut out all old, failed silicone using a utility knife or sealant removal tool.
Deep Clean: Thoroughly clean the tray edge and wall/tile with a mould remover and then isopropyl alcohol (methylated spirits) to remove all soap scum, residue, and moisture, ensuring excellent adhesion.
Dry Completely: Let the area dry fully; sealing over damp surfaces causes immediate failure.
Apply High-Quality Silicone: Use a 100% sanitary silicone sealant (like DOW 785 or similar) designed for wet areas, which offers excellent flexibility, water resistance, and mould resistance.
Use Masking Tape: Apply masking tape above and below where the bead will go for a super-clean, professional finish.
Tool the Bead: Apply an even bead with a sealant gun and smooth it with a tooling tool or wet finger to compact it into the gap.
Remove Tape & Cure: Peel off the tape immediately and allow the sealant to cure fully (check product instructions) before using the shower.

Best solution: Use high-quality sanitary-grade silicone sealant, not plumber’s mait, and apply it with proper surface prep and technique.

To fix a failed seal around a shower tray and prevent serious leaking, here’s the recommended approach:

????? Why Not Plumber’s Mait?
- Plumber’s mait is oil-based and non-setting, which makes it unsuitable for areas exposed to constant water and movement.
- It doesn’t bond well to smooth surfaces like acrylic or ceramic and can degrade over time, especially in wet environments.

? Best Practice: Silicone Sealant
Use a mold-resistant, sanitary-grade silicone sealant designed for bathrooms. Here’s how to do it properly:

1. Remove Old Sealant
- Use a sharp utility knife or sealant remover tool.
- Carefully scrape away all old silicone without damaging the tray or tiles.

2. Clean and Dry the Area
- Wipe down with isopropyl alcohol or a dedicated surface cleaner to remove residue.
- Ensure the area is completely dry before resealing.

3. Apply New Silicone
- Use a high-quality silicone like Dow Corning 785 or similar.
- Cut the nozzle at a 45° angle and apply a smooth, continuous bead along the joint.
- Use a sealant smoothing tool or a wet finger to shape the bead evenly.

4. Allow to Cure
- Let the sealant cure for at least 24 hours before using the shower.
- Check manufacturer instructions for exact curing time.

Use proper silicone and prepare beforehand, must be clean and dry. Do not use for 24 hrs

Clean out old silicone as much as possible.Allow to dry if area has got damp.Use a quality sealant such as CT1 to first fill all gaps as much as possible (use a fine nozzle)then finish with a good sized bead all the way round .The size of bead will depend on size of gap but you will need to cover from tray to tile

The best solution is to remove all the old sealant completely and reseal the shower tray using a high-quality flexible sanitary silicone, not Plumbers Mait. Plumbers Mait isn’t designed for wet areas, doesn’t fully cure, and won’t withstand movement, so it will fail again and continue leaking.

Plumber mate putty here would not be suffice!
You will need to remove any old sealants and then first put a cloth down with a heavy 70kg weight/s in the middle of tray as a minimum. Then reseal all around the wall/sides of tray allow for 20mins to cure and then again apply sealant around the tray rim to walls and use a rubber fugue/squeegee around the sealant to ensure a smooth professional finish all round this ensures two layers of protection and a solid hold to walls/tiles and tray. The weight ensures no flexing when someone stands in the shower and will last at least 10 years without any issues!
The weight is the key here, the rubber profiler is the professionalism and detail to perfection!

I would not recommend using plumber's putty. I would recommend using a good quality sanitary sealant.

In order to do this, all the old sealant must be thoroughly removed and the surface cleaned.

We will then fill up the bathtub and apply the new sealant. I then recommend a good 12-24 hours for the sealant to cure before emptying the bathtub and using it.

Use high-quality sanitary silicone sealant (not Plumber’s Mait) and apply it properly after removing the old seal.

To cut it out and silicon

I would find out why its failed in the first place, as silicone shouldnt fail unless not put on properly in the first place then id use a minimum if a 10mm bead around and leave it for 24hours to cure

Bathroom sealant (silicone)