How to Cut a Shower Door Seal Perfectly: 3 Pro Methods!

Last updated: 9 January 2026

Almost all shower door seals need a bit of a trim to fit your door perfectly.

This guide will show you how to cut a shower screen seal like a pro without cracking the plastic. It’s actually properly simple once you know how!

Still shopping? If you haven't picked up your replacement yet, explore our Shower Door Bottom Seals and Side & Magnetic Seals – they're all designed for easy DIY trimming.

The Right Kit for the Job

Choosing the right gear is the difference between a clean, professional edge and a jagged mess.

Gather your kit:

• Your new shower seal strip
• Garden shears (the secret weapon!) or a small hand saw
• A sharp utility/Stanley knife
• Measuring tape
• A pencil or fine marker

Before You Cut: Pro Prep

Don't go in blades-blazing! Follow these two golden rules to save yourself a headache:

1. Ignore the Old Seal: Don’t just measure the old, crusty one. It’s likely shrunk or warped over time. Always measure the actual glass door for a spot-on fit.
2. Leave a "Safety Buffer": Cut your seal 2-3mm longer than you think you need. You can always shave a bit more off, but you can’t add it back!

Step 1: Measure Twice, Cut Once

Grab your tape and measure the width of your shower door. Mark the seal clearly.

• Top Tip: Hold the seal against the door one last time before you snip.
• Warning: If it's too short, it's game over. You’ll need a fresh replacement seal and a fresh start.

Step 2: Picking Your Method

A. Garden Pruning Shears (The Winner)

This is our top recommendation for UK homes. It’s fast, clean, and a doddle to do. Position the seal with the U-shape channel facing up.

Keep the shears perfectly vertical. Snip! A sharp blade ensures a clean finish without "crushing" the plastic.

B. The Utility Knife & "Snap" Technique

Score: Make a shallow cut all the way around your mark. Keep the U-channel up and press the soft fins out of the way.

Safety First: Always keep the back of the blade facing your fingers to avoid any nasty slips.

Break: Gently snap the strip along your score line. Note: If you’re trimming less than 5cm, stick to the shears—small bits don't snap well.

C. Using a Hand Saw (Last Resort)

Not ideal, but it works in a pinch. Secure the seal on a table edge. Use slow, steady strokes so you don't crack the rigid PVC. Once through, snap it along the contour.

The Finishing Touch: Smoothing Edges

Noticed a few rough bits? Don’t worry, it happens to the best of us.

Our Recommendation: Put the sandpaper away! Simply use the flat side of your knife blade to gently "shave" the edges until they're smooth to the touch.

What’s Next?

Now you've mastered the cut, you're ready for the finish line:

• "I'm ready to fit it!" → Check out our Installation Guide
• "Wait, how thick is my glass?" → How to measure glass thickness accurately
• "I need more expert advice." → Browse the SIMBA Seal Blog

FAQ: Avoiding a "DIY Disaster"

Can I use sandpaper to smooth the edges? +

Don’t do it! Sandpaper creates micro-scratches that trap soap scum and mould. Stick to "shaving" the edge with a sharp blade for a crystal-clear finish.

The cut edge turned white! What do I do? +

This is just "stress whitening" from the plastic bending. The Fix: Use a hairdryer on medium heat for 5-10 seconds. The molecules will relax and the frost will vanish!

Can I use regular kitchen scissors? +

We wouldn't recommend it. Most kitchen scissors aren't tough enough for rigid PVC. You risk cracking the seal or, worse, hurting your hand.

What if I accidentally cut too much off? +

It happens to the best of us. Sadly, a short seal won't stop leaks. You’ll need to order a new one – just remember the 3mm buffer rule next time!