24mm Glazing Packers: When to Use Them Instead of 20mm or 28mm Packers

When buying flat glazing packers, installers often compare 20mm, 24mm, and 28mm options. Each size has its place, but 24mm glazing packers are often the most practical middle-ground choice.

They are wider than 20mm packers, but not as wide as 28mm packers. That makes them useful for installers who want a versatile flat packer for everyday glazing work across uPVC, aluminium, and timber frames.

At GlazingPacker, we stock 24mm × 100mm flat glazing packers in packs of 1000, available in 1mm to 6mm thicknesses.

Why 24mm Glazing Packers Are a Useful Middle Option

24mm glazing packers sit between narrower 20mm packers and wider 28mm packers.

That makes them useful when:

• 20mm feels too narrow for the support point
• 28mm feels wider than necessary
• the job needs a balanced general-purpose packer
• the installer wants a versatile stock option
• the frame or glazing system suits a 24mm support width

For many installers, 24mm packers are a practical everyday choice because they cover a wide range of standard glazing work without being too narrow or too wide.

What Are 24mm Glazing Packers Used For?

24mm flat glazing packers are used to support, level, and space sealed glass units within the frame.

They are useful for:

• uPVC window and door installations
• aluminium frames
• timber frames
• sealed glass units
• conservatories
• curtain walling
• general levelling and support
• keeping glazed units square and properly positioned

Their purpose is to provide stable, consistent support so the unit sits correctly and performs properly over time.

When Should You Choose 24mm Instead of 20mm?

Choose 24mm glazing packers instead of 20mm packers when the installation needs a slightly wider support surface.

20mm packers are useful for narrower glazing systems and compact support points. But if the support area has enough room for a wider packer, 24mm may be the better choice because it gives more contact area while still remaining practical for general glazing work.

Use 24mm instead of 20mm when:

• the glazing channel is not especially narrow
• the support point benefits from a wider packer
• the job needs a more general-purpose flat packer
• the unit needs stable support across a slightly larger area
• you want more flexibility across different frame types

In simple terms, 20mm is the narrower option, while 24mm is the more versatile everyday option.

When Should You Choose 24mm Instead of 28mm?

Choose 24mm glazing packers instead of 28mm packers when the job does not require the wider support surface of a 28mm packer.

28mm packers are useful for wider glazing systems, heavier units, and larger support areas. But not every installation needs that much width. In many standard jobs, 24mm provides enough support while being easier to use in more typical frame situations.

Use 24mm instead of 28mm when:

• the support area does not require a wider 28mm packer
• the job is standard glazing work rather than heavier support work
• the installer wants a balanced all-round stock size
• the frame or system suits a mid-width packer
• 28mm feels wider than necessary for the available space

In simple terms, 28mm is the wider support option, while 24mm is the flexible middle option.

A Simple Size Comparison

A useful way to think about the three sizes is:

• 20mm: narrow and compact
• 24mm: versatile and general-purpose
• 28mm: wider and stronger support surface

This is why 24mm packers are worth stocking even if you already use 20mm and 28mm. They fill the gap between the two.

Why Installers Should Stock 24mm Packers

Installers should stock 24mm glazing packers because they cover many standard glazing situations.

They are especially useful for:

• everyday window installation
• general door glazing
• mixed frame work
• uPVC, aluminium, and timber frames
• jobs where 20mm is too narrow
• jobs where 28mm is more than required

For many trade buyers, 24mm is one of the safest flat glazing packer sizes to keep in regular stock.

Available Thicknesses in 24mm Glazing Packers

Our 24mm flat glazing packers are available in:

• 1mm
• 2mm
• 3mm
• 4mm
• 5mm
• 6mm

This full thickness range gives installers options for fine adjustment, standard support, moderate correction, and heavier load points.

When to Use 1mm 24mm Glazing Packers

Use 1mm 24mm glazing packers for very small adjustments.

They are useful for:

• final levelling
• slight gap removal
• fine-tuning after main packing
• small finishing corrections

This thickness is best when the unit is already close to the correct position and only needs minor adjustment.

When to Use 2mm 24mm Glazing Packers

Use 2mm 24mm glazing packers for light corrections.

They are useful for:

• slightly uneven frames
• small alignment corrections
• light spacing adjustments
• minor levelling under glazing units

2mm is useful when 1mm is not enough, but the job still does not need a standard or heavier support packer.

When to Use 3mm 24mm Glazing Packers

Use 3mm 24mm glazing packers for standard everyday glazing work.

They are useful for:

• typical window installations
• door glazing
• general levelling
• standard sealed unit support
• everyday glazing jobs

For many installers, 3mm is likely to be one of the most-used thicknesses in the 24mm range.

When to Use 4mm 24mm Glazing Packers

Use 4mm 24mm glazing packers where a more noticeable correction is needed.

They are useful for:

• medium gaps
• supporting heavier sections
• aligning uneven openings
• jobs where 3mm is not quite enough

4mm is one of the most useful reasons to stock 24mm packers, because it gives installers an extra middle thickness that is not available in every narrower packer range.

When to Use 5mm 24mm Glazing Packers

Use 5mm 24mm glazing packers where stronger support or larger spacing is needed.

They are useful for:

• larger spacing requirements
• heavier sealed units
• stronger support points
• structural support areas

5mm is one of the core trade thicknesses and is worth keeping in stock if you regularly install windows and doors.

When to Use 6mm 24mm Glazing Packers

Use 6mm 24mm glazing packers when the job needs maximum correction within the 24mm range.

They are useful for:

• large gaps
• uneven substrates
• base packing under frames
• high load-bearing positions
• more demanding installation work

6mm may not be used as often as 3mm, 4mm, or 5mm, but it is important to have available when the job needs it.

Best 24mm Thicknesses for Trade Stock

For most installers, the best 24mm thicknesses to keep in regular stock are:

• 3mm
• 4mm
• 5mm

These three cover the widest range of standard glazing work.

Then keep:

• 1mm and 2mm for fine adjustment
• 6mm for larger gaps and heavier support

This gives installers a balanced 24mm stock setup without relying on one thickness for every job.

Why 24mm Packers Are Good for Mixed Installation Work

Many installers work across different systems and site conditions. One job may involve uPVC windows, another may involve aluminium frames, and another may involve timber glazing or conservatory work.

24mm packers are useful because they are not too specialist. They work well as a general-purpose stock item for installers who need flexibility across different types of glazing work.

If your van stock is too narrow, you may not have enough support area for some jobs.

If your stock is too wide, you may be carrying packers that are more than some jobs require.

24mm is the balanced middle option.

Why 24mm Packers Are Useful for Bulk Buyers

For trade buyers, 24mm flat glazing packers make sense because they are supplied in packs of 1000 and available in a full 1mm to 6mm thickness range.

That makes them useful for:

• self-employed installers
• glazing companies
• maintenance teams
• contractors
• buyers managing multiple vans
• firms that want consistent stock across installation teams

A strong 24mm stock setup reduces the need for last-minute buying and helps installers choose the correct thickness on site.

When Not to Use 24mm Packers

24mm packers are versatile, but they are not always the best choice.

You may want 20mm packers instead if:

• the glazing system is narrower
• the support area is compact
• a 24mm packer feels wider than necessary
• the job specifically calls for a narrower flat packer

You may want 28mm packers instead if:

• the glazing system is wider
• the sealed unit is larger or heavier
• the job needs a broader support surface
• the installation calls for stronger load distribution

The best choice always depends on the actual frame, glazing system, and support requirement.

Common Buying Mistakes to Avoid

When buying 24mm glazing packers, avoid these mistakes:

• buying only one thickness
• ignoring 4mm as a useful middle option
• using 24mm where a narrower 20mm packer would fit better
• using 24mm where a wider 28mm packer is clearly needed
• not keeping 1mm and 2mm for fine adjustment
• not keeping 6mm for larger gaps and base support
• relying on improvised shims instead of proper plastic packers

A good stock setup should include the right width and the right thickness for the job.

Recommended Stock Setup for 24mm Packers

For most installers, a practical 24mm setup would be:

• 3mm for standard everyday glazing
• 4mm for moderate correction
• 5mm for stronger support
• 1mm and 2mm for fine adjustment
• 6mm for large gaps and base packing

For larger installation companies, it may make sense to hold multiple packs of 3mm, 4mm, and 5mm, with lower quantities of the other thicknesses.

Final Thoughts

Use 24mm glazing packers when you need a versatile middle option between narrow 20mm packers and wider 28mm packers.

Choose 24mm instead of 20mm when the job benefits from a wider support surface.

Choose 24mm instead of 28mm when a 28mm packer is more width than the installation requires.

For most trade buyers, 24mm flat glazing packers are a strong general-purpose stock item, especially in 3mm, 4mm, and 5mm thicknesses. Keep 1mm and 2mm for fine adjustment, and 6mm for larger gaps or stronger support work.

Explore our 24mm flat glazing packers in packs of 1000 and choose the thicknesses that match your installation work.