Last updated: 30 July 2026
This guide explains how to reseal a shower door properly.
It covers common leaks, worn seal strips, the tools you may need, and how to reseal the bottom and sides of framed and frameless shower doors. It also explains how glass thickness and gap size affect the choice of replacement seal.
We’ll compare shower seal strips with silicone, include advice from SIMBA CEO James Liu, and highlight common installation mistakes.
Start by identifying where the water is escaping and what type of seal or trim is already fitted.
Check Where the Door Needs Resealing
Before removing anything, dry the shower and look closely at the area where the water appears.
Water beneath the moving glass usually points towards the bottom trim, the gap below the door or the direction of the flexible fin. Water running from the closing edge may involve a vertical or magnetic seal.
A wet patch beside the metal frame is different. The water may be travelling through a fixed joint, a loose frame section or a drainage route inside the enclosure. It can also run along the tray before appearing somewhere away from the original leak.
Start with a small water test rather than running a full shower. Keep the spray away from one section at a time and watch where the first drop appears. This gives a clearer result than looking at the floor after the whole enclosure is wet.
When the source is still uncertain, use our guide to why frameless shower door leaks before deciding which part to replace.
How To Seal a Shower Screen Bottom Or Frameless Shower Door ？
Shower screens are common in UK bathrooms, and leaks often appear around the bottom edge when the seal does not match the glass or gap.
Every bottom seal is designed to work within a particular fitting and 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 shower bottom seals.
But something’s not right.
Can you spot the mistakes?
Mistake 1:
The flexible fin is heavily bent against the surface below. This usually means the fin is too long for the available gap.
Excessive pressure can make the door harder to move and may cause the flexible section to lose its shape sooner.
Mistake 2:
There is no threshold strip beneath the closing area.
A threshold is not required for every shower, but it can help redirect water where spray reaches the outer edge of the tray or screen.
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 filters to compare seals by glass thickness and recommended gap range.
The profile, fitting direction and movement of the door must also be suitable. Matching the gap alone does not guarantee that a bottom seal will fit.
4. Once the seal arrives, Trim the shower seal to match the width of the glass.
5. Push the bottom seal evenly onto the clean glass edge. Most clip-on profiles do not require glue.
6. If the layout requires one, install the threshold strip after checking its position.
For full step-by-step fitting instructions for bottom and side profiles, see our guide to installing a bottom shower door seal strip.
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 SIMBA V456S12 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.
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.
One Possible Solution: Install a 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.
A threshold strip can help where water crosses the outer edge of the frame or tray. Silicone serves a different purpose and is normally used around fixed joints between the frame, wall and shower tray.
Before adding either, confirm where the water is actually escaping.
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 moving glass edges, a replaceable shower seal strip is usually the more suitable option. Silicone remains useful around fixed joints where the frame or glass meets the wall or tray.
The correct method therefore depends on where the leak starts rather than which material is easier to apply.
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
For more help with measuring, cutting, fitting and maintaining replacement seals, see our shower seal fitting and care guides.
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 correct profile and fitting direction, a replacement seal can often reduce or stop water escaping around the glass edge.
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 commonly used to close gaps around the moving edges of glass doors, particularly at the bottom and sides. They stop water from leaking through gaps around the glass — especially at the bottom and vertical edges.
Why Choose SIMBA?
SIMBA has manufactured shower door sealing profiles since 1998, with replacement options for framed and frameless shower doors.
- 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
Our products and fitting guidance are used by DIY customers, bathroom renovators, installers and distributors.
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.