Why Colour-Coded Packers Matter (Standard Industry Colour Chart)
If you’ve ever worked with glazing packers, you’ll know they come in different colours — and those colours aren’t for decoration. They follow a widely accepted industry thickness standard that allows installers to work quickly, consistently, and accurately.
In this article, we’ll explain why colour-coded packers exist, how they help during installation, and provide the standard UK colour chart used across the glazing industry.
What Are Colour-Coded Packers?
Colour-coded glazing packers are plastic spacers with specific, consistent thicknesses, each represented by a standard colour.
The colour tells the installer exactly how thick the packer is without needing to measure it.
This system is now universal across the UK’s glazing and window installation industry.
Why Colour Coding Matters
1. Faster Installation
Installers immediately know which thickness to choose without trial and error.
Example:
Need 3mm? Reach for white.
Need 5mm? Grab a red.
No measuring. No guesswork.
2. More Accurate Packing
Precision is critical when installing:
- uPVC windows
- Aluminium frames
- Door frames
- Glass units
Using the wrong thickness can:
- Twist a frame
- Cause a sash to drop
- Block drainage
- Stress the glass
Colour coding prevents these mistakes.
3. Consistent Results Across Different Jobs
Every installer understands the colour system, so no matter who is on site:
- The measurements are predictable
- The packing is uniform
- The alignment stays consistent
This maintains high installation standards across teams.
4. Helps Maintain Drainage and Ventilation
Glazing requires very specific clearances to maintain:
- Drainage channels
- Expansion gaps
- Ventilation pathways
Knowing exact packer thicknesses ensures nothing is blocked or over-packed.
5. Prevents Stress on Glass
Glass needs even, stable support.
Too thick or too thin packers at the wrong point can create pressure spots that risk:
- Cracked sealed units
- Dropped sashes
- Failed operation over time
Colour-coded packers ensure correct support every time.
Standard Industry Colour Chart (UK)
While manufacturers may vary slightly, the following is the widely used UK standard colour/thickness chart:
| Colour | Thickness |
|---|---|
| Black | 1 mm |
| Green | 2 mm |
| White | 3 mm |
| Blue | 4 mm |
| Red | 5 mm |
| Yellow | 6 mm |
| Brown | 10 mm |
Many installer kits also include:
- 8 mm packers (often grey or beige)
- 12 mm packers
- 15 mm packers
But the core colours above cover 99% of glazing needs.
Where Colour-Coded Packers Are Used
1. uPVC Windows
For correct support, drainage, and toe-and-heeling.
2. Aluminium Frames
Used where precision is essential to avoid frame distortion.
3. Door Frames
Colour-coded packers help maintain consistent reveal gaps and prevent rubbing.
4. General Construction
Installers also use them to level:
- Kitchen units
- Partition walls
- Timber frames
- Flooring
- Decking
The colour system makes spacing predictable and easy.
Benefits of Using Colour-Coded Packers
- Speed up installation
- Improve accuracy
- Prevent costly alignment issues
- Support glass correctly
- Reduce frame distortion
- Maintain drainage channels
- Make inspection easier (visible and identifiable)
They’re a small detail that dramatically improves long-term performance.
Common Mistakes to Avoid
❌ Mixing packer brands with different colour systems
❌ Using random materials like cardboard or wood
❌ Over-packing and restricting drainage
❌ Not replacing missing packers during repairs
❌ Using wedge packers when flat packers are required
Always confirm thickness using the colour chart above.
Final Thoughts
Colour-coded packers are essential for precision and consistency in glazing. They ensure correct support, accurate spacing, and reliable long-term performance. Knowing the colour system — and using the right thickness — is a core part of professional installation.
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