A 2024 UK study by PlumbNation revealed that 7 in 10 Brits struggle with shower door seal install direction.
If you’ve ever muttered ‘shower screen seal – which way round?’ while wrestling with a plastic strip, this guide is your lifeline.
Getting it the wrong way round is one of the most common reasons for shower door leaks — and knowing how to reseal a shower door properly can make all the difference.
But here’s the thing: most websites selling seals don’t tell you this. They assume you’ll figure it out.
In this guide, We’ll walk you through to tell which side faces in, which faces out, and go through 5 common types with simple tips to get it right.
1. Bottom Drip Rail Seals – Which Way Round for Shower Screens?
(SIM-0002a and similar)
Seen this type before?
It's a common bottom door seal for shower door – and that slanted bit on the side (marked 1️⃣ in the picture)
That’s called a drip rail.
A drip rail is a small ridge or lip that helps direct water back into the shower, instead of letting it build up or spill out under the door.
It also helps reduce the water pressure hitting the soft fin (marked 2️⃣) at the bottom.
Which way round does a drip rail shower screen seal go?
Here’s the no‑nonsense bit:
The drip rail (that slanted edge) always faces into the shower. Install it backwards, and water will sneak right under your door!
Simple rule:
If it has a drip rail, the rail side goes inside.
At SIMBA, Like SIM-0002a, a bottom door seal for shower door and it comes with a free threshold seal strip too (that’s the plastic bar that sits on the floor under the door).
Installing it backwards may reduce effectiveness. If you’re dealing with an old or leaking seal, it might be time to reseal your shower door the right way.
Want to learn why shower tray threshold seal matter?
Check out our other video:
Here are some other seals in the same category – they all follow the same rule: drip rail = inside.
2. Seal at Bottom of Shower Door with Dual Fins
(Long fin + short fin combo)
They come with two soft fins sticking out – one long, one short.
Sometimes they’re glued on, sometimes they clip onto the glass. Doesn’t matter – the rule is the same:
- Long fin goes inside the shower
- Short fin faces out
Why?
Because the longer fin helps stop splashes and directs water back inside.
The short one is more of a backup. Together, they work like a mini curtain.
Bonus tip:
If the gap is narrow, trim the long fin to match the short one.
So next time you’re holding one of these and wondering “shower screen seal – which way round?”, remember:
- Long fin = inside
- Short fin = outside
Sorted!
3. For 180-Degree Glass
You’ve probably seen seals like the one in the photo – the U-shaped part is rigid (so it grips the glass), and there’s one soft fin coming out the side.
This is what we call a 180-degree H-shape shower door seal.
So, which way should it face?
The soft fin should face inwards, into your shower.
This advice assumes your shower door opens outwards – which it should.
According to building regulations (IRC P 2708.1, 2000 edition), all hinged shower doors must open outwards for safety reasons.
Why?
Imagine someone slips inside the shower – if the door opens inwards and they’re lying against it, you can’t get in to help.
So, if your door opens outwards (as most should), the soft fin goes inwards.
But if your shower door opens inwards, just flip it – the soft fin should then face outwards.
4. Y-Shape Shower Door Seal
These are designed for 135-degree angled glass panels.
Even if you’re not 100% sure of the angle, if the seal looks like a Y shape and fits at an angle – you’re probably using this type.
The rule is simple:
Soft fin always faces inside the shower.
This also applies if you’re using a Y-shape seal on a 90-degree sliding door – again, soft fin = shower side.
5.Which Way Should a Magnetic Shower Seal Face?
There are two main types of magnetic shower door seals — and yes, direction matters!
1. Flat-top magnetic seals
If the top is flat, it’s a universal fit.
These work with glass doors at 180° angles and don’t have a “wrong” side.
2. Angled-top magnetic seals
On a 180° setup, if you install it backwards, the door might not open properly.
Here’s the general rule:
- The longer edge faces outward (ideal for outward-opening shower doors)
- The shorter edge faces inward
- If your door opens inward, flip that around.
Don’t worry — all SIMBA shower door seals come with clear direction labels and installation videos.
Check out all our magnetic shower door seals here to find the right one for your setup.
6. FAQ
Q: Which side of a drip rail seal faces in?
A: The slanted drip rail always goes inside the shower screen.
Q: Does the long fin or short fin go inwards?
A: The long fin faces in; the short fin faces out.
7. Final Thoughts
One last thing – at SIMBA, all our shower screen seals come with clear installation tips and direction guides.
We don’t just send you a seal and cross our fingers – we make it easy.
And no, you don’t need to force anything into place – Hop over to our product page for the right fit and a smoother install!
Get Your SIMBA Seal Kit Now – 15% Off for First-Time UK Buyers!
This article was edited by Laura.
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Author: Laura Liu & SIMBA Seal Expert Laura joined SIMBA in January 2017 and has since become an integral part of the team. As a seasoned content manager and seal expert, she oversees website optimization and specializes in crafting informative and engaging content about sealing solutions. Her deep knowledge of shower seal technology and market trends ensures SIMBA stays ahead in providing value to customers worldwide. |
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