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Packers Bulk Buy: How Installers Should Stock Their Van for Window and Door Jobs
For window and door installers, packers are not optional extras. They are everyday consumables used across glazing, frame fitting, levelling, spacing, support, and adjustment work.
Running out of the right packers on site can slow the job down immediately. It may force installers to leave site, improvise with unsuitable materials, or use the wrong size because it is the only one left in the van.
That is why buying packers in bulk is one of the simplest ways to keep installation work moving smoothly.
A well-stocked van should include the main flat glazing packer sizes, key thicknesses, bridge packers, wedge packers, and frame packers where required. The aim is not to carry every possible packer in huge quantities. The aim is to carry the right working range so most window and door jobs can be completed without delay.
Why Installers Should Bulk Buy Packers
Installers use packers on almost every window and door job. Even a small installation may require several packers for levelling, support, alignment, or spacing.
Across a week of work, usage can add up quickly.
Bulk buying helps installers:
- avoid running out on site
- reduce emergency trips to merchants
- keep the most-used thicknesses available
- standardise van stock
- reduce wasted labour time
- keep jobs moving without interruption
- buy in a more organised way
For trade buyers, packers should be treated as regular stock, not last-minute accessories.
What Packers Should an Installer Keep in the Van?
A practical van stock setup should include:
- flat glazing packers
- bridge packers
- wedge packers
- frame packers
- adjustment thicknesses
- heavier support thicknesses
Each product has a different role.
Flat glazing packers are used for general glazing support, spacing, and levelling.
Bridge packers are used where drainage and ventilation beneath the sealed unit need to be maintained.
Wedge packers are useful for fine adjustment and precise levelling.
Frame packers are used for window and door frame fitting, especially where frames need to be packed, fixed, levelled, or kept square.
A professional van should not rely on only one type.
The Core Flat Glazing Packers to Stock
For window and door glazing work, the main flat glazing packer sizes to keep in stock are:
These three sizes cover a wide range of glazing jobs.
A simple way to think about them is:
- 20mm for narrower systems and compact support points
- 24mm for general-purpose glazing work
- 28mm for wider systems and stronger support requirements
If you work across different window and door systems, keeping all three sizes in the van gives you more flexibility.
Why 20mm Flat Glazing Packers Belong in Van Stock
20mm flat glazing packers are useful when the job needs a narrower flat packer.
They are suitable for:
- narrower glazing systems
- compact support areas
- standard window glazing
- door glazing
- sealed unit support
- uPVC, aluminium, and timber frames
For installers, 20mm packers are useful when a wider 24mm or 28mm packer is not required.
Recommended 20mm Van Stock
A sensible 20mm stock setup would include:
- 3mm for everyday support
- 5mm for stronger support and larger spacing
- 1mm and 2mm for fine adjustment
If you only want to start with the most useful 20mm thicknesses, begin with 3mm and 5mm. Then add 1mm and 2mm as adjustment stock.
Why 24mm Flat Glazing Packers Belong in Van Stock
24mm flat glazing packers are a strong middle-ground option. They are wider than 20mm packers but not as wide as 28mm packers.
They are useful for:
- general window installation
- door glazing
- uPVC frames
- aluminium frames
- timber frames
- sealed glass units
- conservatories
- curtain walling
For many installers, 24mm is one of the safest sizes to keep in regular van stock because it suits a broad range of standard glazing work.
Recommended 24mm Van Stock
A sensible 24mm stock setup would include:
- 3mm for standard everyday glazing
- 4mm for moderate correction
- 5mm for stronger support
- 1mm and 2mm for fine adjustment
- 6mm for larger gaps and base support
If you are bulk buying for regular trade work, prioritise 3mm, 4mm, and 5mm first.
These are likely to be the most useful working thicknesses.
Why 28mm Flat Glazing Packers Belong in Van Stock
28mm flat glazing packers are useful when the installation needs a wider support surface.
They are suitable for:
- 28mm glazing systems
- wider support points
- larger sealed units
- heavier glazing jobs
- uPVC windows and doors
- aluminium and timber frames
- curtain walling
- conservatories
For installers who work on larger windows, doors, or wider glazing systems, 28mm packers should be part of the core van stock.
Recommended 28mm Van Stock
A sensible 28mm stock setup would include:
- 3mm for standard support
- 4mm for moderate correction
- 5mm for stronger support
- 1mm and 2mm for fine adjustment
- 6mm for larger gaps and heavier support
For most trade buyers, the key 28mm thicknesses to bulk buy first are 3mm, 4mm, and 5mm.
Then keep 1mm, 2mm, and 6mm available for specific jobs.
The Most Important Thicknesses to Bulk Buy
Across flat glazing packers, the most useful thicknesses for installers are usually:
- 3mm
- 4mm
- 5mm
These sizes cover a large share of everyday window and door glazing work.
3mm Packers
3mm packers are useful for standard support, general levelling, and everyday sealed unit positioning.
They are one of the first thicknesses most installers should keep in bulk.
4mm Packers
4mm packers are useful when 3mm is not quite enough.
They work well for moderate correction, slightly uneven openings, and jobs that need a bit more support.
5mm Packers
5mm packers are useful for larger gaps, stronger support, and heavier sealed units.
They are especially important for installers who regularly work with larger windows or doors.
Adjustment Packers to Keep Available
Not every job needs a 3mm, 4mm, or 5mm packer. Sometimes the unit is almost in the correct position and only needs a small correction.
That is why installers should also keep:
- 1mm packers
- 2mm packers
These are useful for:
- final levelling
- fine adjustment
- small gap correction
- finishing work after the main packers are in place
They may not be used as quickly as the core thicknesses, but they are important when accuracy matters.
Heavier Support Packers to Keep Available
For larger gaps, base packing, or heavier support points, installers should keep 6mm packers where available.
6mm packers are useful for:
- larger gaps
- uneven openings
- base packing
- high load-bearing points
- heavier installation conditions
They may not be used on every job, but they are important to have available when the site conditions require them.
Bridge Packers for Window and Door Jobs
Flat glazing packers are important, but installers should also keep bridge packers in the van.
Bridge packers are used where the sealed unit needs support while still allowing drainage and ventilation beneath the glass.
They are useful for suitable uPVC window and door systems where water movement and airflow beneath the sealed unit matter.
Bridge packers are especially important because using the wrong packer type in the wrong place can affect drainage. If a system requires a bridge packer, a standard flat packer may not be the right choice.
Why MSBP Is Useful for Van Stock
For installers working across mixed uPVC systems, MSBP (Multi-System Bridge Packer) can be a useful bridge packer to keep in the van.
Instead of carrying multiple profile-specific bridge packers, MSBP is sold as a multi-system bridge packer for a wide range of uPVC window and door profiles.
This can help reduce van stock complexity, especially for installers who regularly work on different systems.
MSBP is particularly useful for:
- uPVC window installation
- uPVC door glazing
- conservatory glazing
- mixed system repair work
- installers who want fewer bridge packer variations in the van
A practical van stock setup should include flat glazing packers for general support and bridge packers where drainage and ventilation beneath the sealed unit are needed.
Wedge Packers for Fine Adjustment
Wedge packers are useful for fine adjustment and precise levelling.
They are not always used in the same way as flat glazing packers, but they are useful when the installer needs more control during fitting.
Wedge packers can help with:
- small positional corrections
- levelling
- adjustment during installation
- fine-tuning before final fixing or glazing
For installers, wedge packers are worth keeping in the van because they help solve small alignment issues quickly.
Frame Packers for Window and Door Installation
Frame packers are different from glazing packers.
Glazing packers are mainly used around or beneath the sealed glass unit.
Frame packers are used when fitting, levelling, spacing, or fixing the frame itself.
Installers should keep frame packers available for:
- door frame installation
- window frame installation
- keeping frames plumb and square
- packing behind fixings
- levelling frames before final fixing
- correcting uneven openings
If you install both windows and doors, frame packers should be part of your van stock, even if flat glazing packers are used more often.
Suggested Van Stock for a Self-Employed Installer
For a self-employed installer or small team, a practical starting setup would be:
- 20mm flat glazing packers in 3mm and 5mm
- 24mm flat glazing packers in 3mm, 4mm, and 5mm
- 28mm flat glazing packers in 3mm, 4mm, and 5mm
- 1mm and 2mm packers for fine adjustment
- 6mm packers where available for heavier support
- bridge packers for suitable uPVC systems
- wedge packers for fine adjustment
- frame packers for frame fitting work
This setup gives a strong working range without overloading the van.
Suggested Van Stock for Busy Installation Teams
For a busier installation team, stock should be managed in larger quantities.
A good setup could include:
- multiple packs of 24mm 3mm, 4mm, and 5mm
- multiple packs of 28mm 3mm, 4mm, and 5mm
- regular stock of 20mm 3mm and 5mm
- lower quantities of 1mm and 2mm adjustment sizes
- 6mm stock for larger gaps and base support
- MSBP or other bridge packers for suitable systems
- wedge packers for adjustment
- frame packers for door and window frame installation
This makes it easier to restock vans consistently and avoid each installer carrying a different mix of products.
Suggested Stock for Glazing Companies and Contractors
For glazing companies, contractors, and businesses managing multiple vans, packer stock should be handled like any other regular consumable.
A practical company setup should include:
- warehouse stock of core flat glazing packer sizes
- van stock lists for each installer
- minimum reorder levels
- separate stock for glazing packers, bridge packers, wedge packers, and frame packers
- regular review of which thicknesses move fastest
This helps prevent overbuying slow-moving sizes while still keeping the most important products available.
Why Installers Should Not Rely on Improvised Packers
Some installers still use timber, cardboard, offcuts, or other materials as improvised packers.
That may seem convenient, but it can create problems.
Purpose-made plastic packers offer:
- consistent thickness
- cleaner support
- better long-term stability
- easier size identification
- more predictable results
- faster installation
- reduced risk of poor fitment
For trade work, improvising with unsuitable materials is not worth the risk.
Common Van Stock Mistakes to Avoid
Avoid these common mistakes when bulk buying packers:
- carrying only one packer width
- carrying only one thickness
- having no fine adjustment sizes
- running out of 3mm, 4mm, or 5mm stock
- carrying flat packers but no bridge packers
- forgetting frame packers for frame fitting work
- relying on timber or cardboard shims
- not checking stock before larger jobs
- letting every van carry a different setup
The best approach is to create a standard stock list and restock before the van runs low.
How Often Should Installers Reorder Packers?
The right reorder frequency depends on how many jobs you complete each week.
A self-employed installer may only need to reorder when core thicknesses run low.
A larger team may need a more structured system.
A simple rule is to reorder before you open your last pack of a frequently used size.
For example, if 24mm 3mm and 28mm 5mm are regularly used, do not wait until the final few packers are left. Reorder while you still have enough stock to complete upcoming jobs.
Best Bulk Buying Strategy
The best bulk buying strategy is to divide stock into three groups.
Core Stock
These are the sizes used most often.
Examples:
- 24mm 3mm
- 24mm 4mm
- 24mm 5mm
- 28mm 3mm
- 28mm 4mm
- 28mm 5mm
- 20mm 3mm
- 20mm 5mm
These should be bought in higher quantities.
Adjustment Stock
These are useful but usually used in smaller quantities.
Examples:
- 1mm packers
- 2mm packers
- wedge packers
These should be available in the van but may not need to be bought as heavily as the core stock.
Specialist Stock
These are important for specific jobs.
Examples:
- 6mm packers
- bridge packers
- frame packers
- MSBP bridge packers
These should be stocked based on the type of work your team handles.
A Simple Van Stock Checklist
A good installer van should carry:
- 20mm flat glazing packers
- 24mm flat glazing packers
- 28mm flat glazing packers
- 1mm and 2mm adjustment thicknesses
- 3mm, 4mm, and 5mm core thicknesses
- 6mm heavier support thicknesses where available
- bridge packers
- wedge packers
- frame packers
This gives installers a practical working range for most window and door jobs.
Final Thoughts
Bulk buying packers is one of the easiest ways for installers to reduce site delays and keep work moving.
For window and door jobs, the strongest van stock setup should include:
- 20mm flat glazing packers for narrower support points
- 24mm flat glazing packers for general glazing work
- 28mm flat glazing packers for wider systems and stronger support
- 3mm, 4mm, and 5mm as core working thicknesses
- 1mm and 2mm for fine adjustment
- 6mm where available for larger gaps and heavier support
- bridge packers for suitable systems where drainage matters
- wedge packers for precise adjustment
- frame packers for door and window frame fitting
A properly stocked van saves time, reduces improvisation, and helps installers complete jobs more professionally.
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