This article provides a detailed explanation of how to reseal shower door effectively.
Whether you're tackling leaks or worn-out seals, we’ll guide you through everything you need to know—from the essential tools to sealing both framed and frameless shower door bottoms and sides, plus choosing the perfect shower seal strip based on your glass thickness.
We’ll also compare resealing methods using seal strips versus silicone, share expert advice from SIMBA’s CEO - James Liu, and help you avoid common mistakes.
Now, let’s talk about how to reseal a shower door quickly and efficiently—in just 5 minutes.
Why Is My Shower Door/Shower Screen Leaking?
Let’s take a closer look:
1. No Seal Strip or Threshold Installed
Some frameless shower screens are sold or installed without proper bottom seals and threshold seals.
It might be assumed that a sloped floor is enough to direct the water away — or that the glass alone will do the job.
But here’s the reality:
When water hits the glass with force, even a slight slope often isn't enough to stop leaks.
Without a proper bottom shower door seal, water can easily escape underneath — soaking your floor and potentially damaging it long-term.
2. Old, Brittle or Discoloured Seal Strips
PVC glass shower door gasket doesn’t last forever. Over time, it hardens, yellows, or even cracks — and once that happens, its sealing ability disappears.
If your shower used to be watertight but now leaks, the most likely culprit is the seal strip.
Good news?
SIMBA’s shower screen seals have been tested to last over 30,000 uses — that’s about 8+ years in a busy family home with 3 kids.
3. Wrong Size or Installed the Wrong Way Round
Even the best bath trim seal won’t work if it doesn’t fit properly — or if it’s installed backwards.
Our range of seal strips for baths and showers are clearly labelled with compatible glass thicknesses and sealing ranges.
Just follow our measurement guide to make sure you’re choosing the right fit.
I have written a detailed article explaining the correct installation direction of shower door seal strips.
If you’re facing a frameless shower door leak and don’t see your issue listed above, drop us an email.
We regularly update our guides based on real customer questions — so your problem might help others too.
How To Seal a Shower Screen Bottom Or Frameless Shower Door ?
Shower screens are the most common type of shower enclosure in UK bathrooms.
And not surprisingly, they’re also the most prone to leaking — especially at the bottom — if you're not familiar with how shower seals work.
So, what's the real problem?
Every shower screen seal is designed to match a specific gap range.
If the seal doesn’t match the gap, water will find its way out.
Let’s take a real example from one of our customers.
At first glance, the seal in the photo looks like our popular SIM-0003a.
But something’s not right.
Did you notice the blue tint on the shower screen seal in the photo? That’s not just a camera effect — it’s a common sign of lower-quality PVC. High-grade seals are usually crystal clear, without any blue or cloudy appearance. Want to learn more? Check out our detailed guide: How to Tell the Quality of a Shower Seal Strip. |
Can you spot the mistakes?
Mistake 1:
The soft fin of the seal is bent and crushed.
That’s a clear sign the fin is too long, and the gap is too narrow.
(Every SIMBA seal lists its exact sealing range — no guesswork needed.)
Mistake 2:
There’s no threshold strip installed.
This matters. Whether you’re dealing with a frameless screen or a full enclosure, the bottom edge takes the biggest hit from water flow.
Without extra protection, leaks are almost guaranteed.
So, how to seal a shower screen properly?
Step-by-Step: How to Seal a Bath Shower Screen — Simple and Smart
1. Measure the gap at the bottom of your shower screen and check your glass thickness.
2. Visit SIMBA’s Bottom Seal Strip collection page.
3. Use the left-side filters to choose a seal that matches your gap size and glass thickness.
(As long as the gap fits, any bottom seal strip will work with your screen.)
4. Pick the right bath bottom seal from our collection:
(Example: SIM-0003a has a 23mm fin, but works best for gaps between 18–23mm)
5. After placing an order and receiving the goods. Trim the shower seal to match the width of your screen.
6. Push on the bottom seal to install — no tools or glue required.
7. install shower threshold seals.
Every bottom seal strip order from SIMBA includes a free shower threshold (dam strip).
Trim it to the required length and install it on the outside of your seal strip to block water effectively.
This method is suitable for frameless shower doors or shower screens.
so, now you know how to seal a shower screen over a bath?
“Installed the SIM-0003a with the threshold strip — finally a dry floor after every shower. Took me less than 10 minutes.”
— Mark, Leeds
How to Seal Frameless Glass Shower Panels
Sealing a frameless glass shower panel is simple—as long as you choose the right seal strip.
We've already covered how to seal the bottom of a shower door, and the good news is: the same technique applies to frameless glass panels.
Frameless showers rely heavily on precisely fitted seal strips along the edges—vertical and bottom—to prevent water leaks while maintaining that sleek, minimalist look.
Need help choosing the right one? Check out our Seal Strip Buying Guide for frameless shower doors.
How to Seal the Bottom of a Framed Shower Door
Framed shower doors are generally easier to reseal than frameless ones.
The metal frame itself acts as a built-in water barrier, helping to guide water back into the shower.
But if you're noticing leaks at the bottom of the metal frame, here's a simple fix that doesn’t involve removing the entire enclosure.
Best Solution: Install a SIMBA Threshold Strip
We recommend using a SIMBA clear threshold seal strip to block water escape:
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Clean the floor surface thoroughly—no dust, no moisture.
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Peel off just a small section of the backing tape on the strip.
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Start applying the strip to the outside edge of your shower frame, slowly peeling and pressing as you go.
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Once installed, let it sit for 12 hours before using the shower to ensure full adhesion.
Pro Tip: Don’t peel off the entire adhesive backing at once—this makes alignment tricky, and the adhesive is strong, making it hard to reposition if misaligned.
Using a threshold strip is a cleaner, more effective alternative to silicone.
Silicone tends to collect mold over time and can be hard to clean.
How to Install a Shower Door Seal Strip
We've put together a detailed guide on how to install shower door seal strips, covering both bottom seals install and side seals install step by step.
Seal Strip vs Silicone:Which Resealing Method Works Best?
If you're wondering how to reseal a shower door, you’re likely choosing between traditional silicone sealant and a bath seal strip. Here's a quick comparison:
1. Installation
Silicone needs careful application and curing. Mistakes are hard to fix.
Seal strips are easier—just clip or stick them on. No tools or drying time needed.
2. Appearance & Cleaning
Silicone can turn yellow and grow mold.
Seal strips (like SIMBA's) are clear, tidy, and easier to keep clean.
3. Replacement
Old silicone is tough to remove and reapply.
Seal strips are quick to replace with no mess.
4. Performance
Seal strips are designed for specific gap sizes and glass thicknesses.
They stay sealed longer and handle water pressure better.
For sealing shower doors or screens, seal strips work better in almost every way.
Silicone is still useful in corners or bathtubs—but for doors, seal strips are the smarter choice.
Common Mistakes to Avoid
- Avoid rinsing the seal strip with hot water over 60°C
- Don't use a seal strip that doesn't match your gap size
- Avoid using soap water or detergent as lubricant
- Don't use a hot air gun to soften the seal strip
Want more tips? Check out our [Seal Strip Buying Guide] for full installation and care instructions.
FAQ About How To Seal Glass Shower Door
How to seal a frameless glass shower door?
This applies to both frameless shower doors and fixed glass panels. To seal a glass shower door effectively, you simply need the right seal strip — fitted properly. With the right product, a leak-free bathroom is absolutely achievable.
Should I install the seal on the inside or outside of the glass?
In most cases, seal strips should be installed on the inside of the shower, where they can block water before it escapes. Always check the seal’s design and your door type for the best fit.
How to waterproof a glass shower door?
Shower door seal strips are the most effective way to waterproof glass shower doors. They stop water from leaking through gaps around the glass — especially at the bottom and vertical edges.
Why Choose SIMBA?
We’re not just another temporary seller on a platform — we’re a dedicated manufacturer with over 20 years of experience in making high-performance shower door seal strips.
- UK warehouse with in-stock items ready for immediate shipping
- 10-month product warranty
- 30-day return guarantee
- Hundreds of models to fit nearly all types of shower doors
- Better prices for wholesale, and OEM welcome
- Dedicated after-sales support
- All products certified by ISO9001 and REACH standards
We’ve helped countless bathroom renovators, trade installers, distributors, and DIY customers.
To ensure you pick the right product and avoid common pitfalls, check out our detailed Guide to Judging Shower Door Seal Strip Quality.
If you need reliable, long-lasting seal strips — we’re your answer.
Ready to Fix That Leak?
Know what’s wrong with your shower door now?
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Let’s make your shower dry, sleek, and leak-free — with one smart seal from SIMBA.