If you're installing a new shower — or your current one is looking a little worse for wear — sealing it properly is one of the most important steps. Without a good silicone sealant, water can sneak behind your tiles, causing damage to your walls, floor, and even leading to black mould.
Sealant doesn't last forever. Over time, it can lose its grip, peel away, or become discoloured and mouldy from constant moisture. The good news? You don't need to call a handyman.
This DIY guide will walk you through how to seal a shower step-by-step, with helpful tips, tools, and a bit of know-how to make sure your shower stays watertight and fresh.
So grab your sealant gun — it's easier than you think!
Why Sealing Your Shower Is So Important
Shower sealant might seem like a small detail, but it does a huge job. It creates a watertight barrier between your shower and the rest of your bathroom, protecting your walls, floors, and substructure from moisture.
Without it? You’re risking mould growth, leaks, water damage, and even structural issues behind the tiles — all of which can lead to costly repairs down the line.
Whether you're sealing a brand-new shower or replacing mouldy old sealant, doing it properly means:
- No more water sneaking behind tiles
- A clean, polished finish around your shower tray
- A fresher, more hygienic bathroom
It’s a simple task with a big payoff, and this guide is here to help you do it right.
How Long Should Shower Sealant Last?
The lifespan of your silicone sealant really comes down to a few key factors: how often you use your shower, the quality of the sealant you applied, how well the bathroom is ventilated, and how regularly you clean it.
If you’ve used a cheaper sealant, you might find it only lasts six to twelve months before it starts peeling or letting mould in. In contrast, a good-quality, mould-resistant silicone sealant can last anywhere from five to ten years when applied correctly and looked after.
In reality, though, most showers benefit from being resealed every two to three years, especially in busy households or homes with poor airflow.
If you notice mouldy sealant, cracks, or spots where it’s peeling away from the shower tray, it’s definitely time to reseal. And if mould seems to be a constant problem, it might be worth improving ventilation or running a dehumidifier to help keep moisture levels under control.
How Often Should You Reseal a Shower?
How often you need to reseal a shower depends on usage, ventilation, and the type of silicone sealant you use. Showers tend to need resealing more often than baths simply because they’re used more frequently.
If you’ve used a low-quality product, it may need replacing every 6 to 12 months. A higher-grade sealant can last up to two years or more, especially if the bathroom is well-ventilated.
Learning how to reseal a shower properly means you can stay ahead of problems like mould, cracking, or peeling. Mouldy sealant is a big red flag.
The second you notice mould, clean it immediately — waiting too long makes resealing unavoidable. Better airflow or a dehumidifier can also help you go longer between applications and prevent leaks from forming in the first place.
How Often Should You Reseal a Shower?
Similar to the first section in this guide, it really does depend on your personal circumstances, as well as issues like mould, and the frequency you use the shower. Often, the sealant on a bath will need to be replaced a lot less because it is not used as often as a shower.
If you use a sealant that is poor in terms of quality, it is often advised that you replace it every 6-12 months to ensure that it remains adhesive and watertight.
If your shower is used regularly, you can usually get away with resealing it every two years without an issue, as it will generally remain waterproof (especially if you are using a good quality sealant).
Mould can be an issue as well, causing you to need to reseal more regularly, but there is a way around this. The second you spot the mould, make sure to clean and remove it instead of leaving it for later; because this is how it ends up being too late. You should also consider improving ventilation.
Tools and Materials You’ll Need
Before you get started, make sure you’ve got everything you need for a clean, professional-looking finish:
Got everything? Great — let’s move on to sealing your shower step by step.
Step-by-Step Guide: How to Apply Silicone Sealant
Now that you’ve gathered your tools and prepared the area, it’s time to get to work. The good news is, applying silicone sealant is simple when you take it step by step. Just go slow, don’t rush, and you'll end up with a neat, watertight seal that looks like it was done by a pro.
Step 1: Check Your Sealant and Get Set Up
First, double-check that you’re using silicone sealant — not grout or caulk. Only silicone is fully waterproof and flexible enough for the joints and edges around your shower tray. Once you’ve confirmed that, load the tube into your sealant gun. You’re ready to go.
Also Read: How to Remove and Replace Tile Grout
Step 2: Apply Masking Tape for Clean Lines
Take your masking tape and run it along the top edge of the shower tray, leaving a 3mm gap between the tape and the wall. Then, apply a second strip of tape along the wall, again leaving about a 3mm space from the edge of the tray.
This creates a perfect channel for your sealant to sit in. It also catches any slips or spills, so you won’t end up with a mess on your surfaces — just peel it off later for a clean finish.
Step 3: Cut the Nozzle and Apply Sealant
Cut the nozzle on your sealant tube at the narrowest point, usually at a 45-degree angle, and slowly squeeze the trigger on your gun. Apply the silicone along the edge of the shower tray with a steady hand.
Move slowly and make sure you’re filling every gap — don’t worry if it’s not perfect yet, you’ll smooth the sealant in the next step. If any excess starts to escape, push it back into the gap with your finger or a small tool.
Step 4: Build a Second Layer (Optional)
Once your first pass is done and you’ve filled all the joints, you can go over the same line with a slightly wider bead if you want extra protection. Just cut the nozzle a bit further down to widen the opening and apply a second layer directly over the first. Make sure everything is still airtight and smooth.
Step 5: Smooth It Out
Wet your finger slightly or grab your sealant smoothing tool, and gently run it along the line of silicone. This presses the sealant into the joint and smooths out the surface for a professional finish. You’ll instantly see a difference — and this step helps seal the deal (literally).
Step 6: Remove the Masking Tape
Carefully peel the masking tape away while the sealant is still wet. Do this slowly to avoid pulling any silicone up with it. Removing the tape while the sealant is fresh ensures you get those nice crisp edges without dragging the sealant out of place.
Step 7: Clean Up
Wipe any leftover sealant from the nozzle and pop the cap back on. Don’t forget to release the pressure on the sealant gun — otherwise, it might keep oozing. Use a damp cloth to gently wipe away any stray silicone from your shower tray or tiles. It’s best to do this before the sealant dries completely.
Also Read: How to Remove Silicone from Shower
How Long Does Silicone Sealant Take to Dry (and Cure)?
Once you’ve finished applying your new sealant, it’s important to let it dry properly before using the shower. Drying time depends on the type of sealant and the temperature in your bathroom.
Some fast-dry sealants claim to set in an hour, but these are usually lower quality and tend to break down quicker. High-quality silicone sealants typically take 24 hours to cure in a warm room and up to 36 hours in cooler conditions.
Try to keep the bathroom at around 18°C for the best results — too cold, and it’ll take forever to dry; too warm and the sealant might form a surface film or struggle to stick.
The key is patience: give it the full drying time to ensure a watertight, long-lasting finish.
Do Shower Tiles and Grout Need Sealing?
While sealing the edges of your shower with silicone sealant is essential, you might also need to seal the tiles and grout, depending on the type you have. Most ceramic and porcelain tiles don’t need sealing, but natural stone tiles (like slate or marble) usually do.
As for the grout, it’s porous — which means water can seep through over time. Applying a grout sealer once every year or two helps protect against moisture, mould, and staining.
Not sure if your tile needs sealing? Try applying a bit of water or sealant to a small test area. If it soaks in, go ahead and seal the whole surface. If it beads up, you’re good to go.
Aftercare and Maintenance Tips
Once your sealant has dried fully and your shower is back in action, a little regular care goes a long way in keeping it looking fresh and watertight.
First off, try to keep the area dry between uses. Wipe down the shower tray and walls with a towel or squeegee when you’re done showering — this helps stop water from sitting around and causing problems like mouldy sealant or black spots.
Good ventilation is key, too. If your bathroom doesn’t have an extractor fan, crack a window or consider getting a dehumidifier to reduce moisture build-up in the air. Less moisture means less mould — and a longer-lasting seal.
You should also keep an eye on the condition of the silicone over time. If you notice peeling, cracking, or discolouration that doesn’t clean off, it’s likely time to reseal your shower. Catching issues early can help you avoid leaks and costly repairs later on.
And remember, a little upkeep now means fewer headaches down the line.
Common Mistakes to Avoid When Sealing a Shower
Even though sealing a shower is a pretty simple DIY job, there are a few easy mistakes that can mess with your finish — or worse, lead to leaks down the line. Here are a few to watch out for:
- Not cleaning the area properly: If there's dust, soap scum, or moisture left behind, the sealant might not stick properly. Make sure everything is completely clean and dry before applying silicone.
- Skipping the masking tape: This might seem like an extra step, but masking tape is what helps give you that neat finish. Without it, the sealant can spread too far or look uneven.
- Applying over old or mouldy sealant: Trying to seal over remaining sealant or mildew never works — it’ll peel off again quickly. Take the time to remove old silicone completely using a utility knife or sealant remover.
- Using the shower too soon: It might look dry on the surface, but that freshly laid sealant still needs time to cure. Always wait the full 24 to 36 hours (depending on conditions) before using your shower.
- Rushing the job: A slow and steady way gives you better control. If you rush the bead, you’ll end up with gaps, bubbles, or a messy finish. Take your time — it’s worth it.
Conclusion: Seal Like a Pro
Hopefully this guide has helped you feel more confident about how to seal a shower — whether you're doing it for the first time or replacing old silicone sealant. It's a surprisingly simple task that can make a big difference to your bathroom's look and longevity.
Just remember to take your time, prep the area properly, and don’t rush the drying process. A neat, professional-looking finish is all about patience and following each step carefully.
We'd love to know how your project went! Did this guide help? Got questions, tips, or even a photo of your freshly sealed shower? Drop us a comment below — we always enjoy hearing from fellow DIYers.
