May 2026

Can Polycarbonate Roofing Withstand Snow and Strong Winds? (UK Weather Guide)

If you’re considering a polycarbonate roof for a pergola, lean-to, veranda or carport, you may be wondering how well it will hold up in harsh weather.

👉 Can polycarbonate roofing withstand snow and strong winds in the UK?

The short answer is yes — when installed correctly. Polycarbonate is a highly durable material designed for outdoor use, but its performance depends on factors such as sheet thickness, rafter spacing and installation quality.

In this guide, we explain how polycarbonate roofing performs in UK weather conditions and how to ensure your roof is strong enough to handle wind, rain and snow.

Helpful resources mentioned throughout this guide:

Cut-to-size polycarbonate sheets
https://polycarbonatex.co.uk/products/cut-to-size-multiwall-polycarbonate-sheet

Multiwall accessories
https://polycarbonatex.co.uk/collections/multiwall-accessories

Glazing bar end caps
https://polycarbonatex.co.uk/collections/multiwall-accessories/products/corotherm-multiwall-polycarbonate-sheet-glazing-bar-end-cap

Delivery policy
https://polycarbonatex.co.uk/pages/delivery-policy

Is Polycarbonate Strong Enough for UK Weather?

Polycarbonate is known for its:

• High impact resistance
• Flexibility without breaking
• Ability to withstand temperature changes

In fact, polycarbonate is significantly more impact resistant than glass, making it ideal for outdoor roofing.

How Polycarbonate Performs in Strong Winds

Wind Resistance

Polycarbonate roofing can perform very well in windy conditions if:

• Sheets are properly secured
• Glazing bars are installed correctly
• Fixings are tight and appropriate

What Can Go Wrong in High Winds

Problems usually occur when:

• Sheets are loose
• Glazing bars are not fitted properly
• End caps are missing
• Rafter spacing is too wide

How to Improve Wind Resistance

✅ Use correct sheet thickness

• 10mm → standard use
• 16mm → better for exposed areas

✅ Ensure proper rafter spacing

Closer spacing = more support

✅ Use quality glazing bars

Browse here:
https://polycarbonatex.co.uk/collections/multiwall-accessories

✅ Install end caps

Prevents lifting in strong winds

https://polycarbonatex.co.uk/collections/multiwall-accessories/products/corotherm-multiwall-polycarbonate-sheet-glazing-bar-end-cap

How Polycarbonate Performs in Snow

Snow Load Capacity

Polycarbonate sheets can handle typical UK snowfall when:

• Correct thickness is used
• Roof pitch is adequate
• Structure is properly built

Risk Factors with Snow

Problems may occur if:

• Roof is too flat
• Sheets are too thin
• Rafter spacing is too wide

How to Improve Snow Performance

✅ Use thicker sheets

• 16mm recommended for larger roofs

✅ Increase roof pitch

Minimum:

👉 5°

Better:

👉 7–10°

This allows snow to slide off more easily.

✅ Ensure strong structure

The timber frame must support the load.

Polycarbonate vs Other Materials in Bad Weather

Polycarbonate vs Glass

Polycarbonate:

• More impact resistant
• Less likely to shatter

Glass:

• Can break under impact

Polycarbonate vs PVC

Polycarbonate:

• Stronger
• More durable

PVC:

• Can become brittle over time

Does Hail Damage Polycarbonate?

Polycarbonate is highly resistant to hail damage.

Unlike glass, it:

• Absorbs impact
• Does not shatter
• Remains flexible

This makes it suitable for exposed outdoor environments.

How Roof Design Affects Weather Performance

Rafter Spacing

Closer rafters:

• Reduce flexing
• Improve strength

Sheet Thickness

Thicker sheets:

• Resist movement
• Handle heavier loads

Glazing Bars

Properly installed bars:

• Secure sheets
• Prevent lifting

Fixings

Correct fixings:

• Prevent movement
• Improve stability

Common Mistakes That Reduce Weather Resistance

Avoid these:

❌ Using thin sheets on large roofs

Leads to sagging and movement

❌ Wide rafter spacing

Reduces support

❌ Missing end caps

Allows wind to lift sheets

❌ Poor installation

Creates weak points

How to Make Your Roof Storm-Proof

✅ Use 10mm or 16mm sheets

Stronger and more stable

✅ Ensure proper installation

No loose components

✅ Use full accessory system

Tapes, bars, fixings

✅ Check roof regularly

Spot issues early

When to Replace Sheets

Replacement may be needed if:

• Sheets are cracked
• Movement is excessive
• Roof is unstable

Order replacements here:
https://polycarbonatex.co.uk/products/cut-to-size-multiwall-polycarbonate-sheet

Accessories for Stronger Roofing

A complete system includes:

• Glazing bars
• End caps
• Fixings
• Sealing tapes