Plastic Shims and Packers - Playing an Important Role in the Building Industry

What are shims? Understanding plastic packers in construction. 

A shim is fundamentally a manufactured component used for levelling or holding up space in building applications, from precast tilt-up concrete panels in the assembly of warehouses through to aligning of window & door frames in residentail dwellings. They play an all-important role in providing a gap in a joint or supporting an object. Either way they provide a permanent solution that needs protection from UV light. Plastic shims and packers are designed to be easy to use and are very versatile. In fact their uses are endless! They can be screwed, stacked, drilled, nailed and cut. Previously, packers were a simple do-it-yourself wood shim from building waste, however to the professional  tradesperson or the weekend warrior an engineered product is a prerequisite for quality work. In today's article we shall review the different types of packers and shims to assist in understanding their differences so you can purchase in confidence knowing that you have the correct plastic shim or plastic packer for your application. 

Key Benefits of Shims, Packers and Spacers. 

A shim, packer or spacer is a thin item used to fill or uphold a gap or space between objects. Shims are typically used in order to support, and adjust for a better fit, or level an item. Key shim advantages include. 

• Heavy duty plastic made of polypropylene making them ideal for heavy loads and compression. 
• Wide range of different sizes and gauges with select shims weight rated for loads up to 20 tons. 
• Adaptable can be cut, drilled, nailed, stacked and colour-coded for hassle-free selection.  

Where are plastic shims used?

Plastic shims and packers are an important everyday building accessory like sealants, and adhesives. They are the ultimate leveling solution with 101 uses, covering most facets of the construction process and trades. Plastic shim selection is most important and can sometimes determine the success of the work. For instance, if a fragile stone is selected for a wall cladding, the contractor may have little to no control over that material's performance, however the success of the surface may depend upon the plastic packer supporting the stone.

Plastic Shim and Packer Applications. 

• Levelling & packing of precast tilt up concrete panels.
• All types of carpentry work & numerous other building trades.  
• Cladding and façade applications and so much more. 

How do you use a plastic packing shim?

This depends on your application. As an example, let us consider the installation of a window. Once the window is seated into its opening, you can place shims in gaps between the window and the wall to level out and support the window. A mallet is used to gently tap the shim into place and then a level to check that the window is plumb.

If one shim is not thick enough for the required adjustment, tap another shim next to or on top of the first one, but face it the opposite way. Once the window is plumb and level, drive a nail or screw from the casing, directly through the shims and into the framing to secure it. Job well done!

Horseshoe shaped plastic packers for lightweight applications

Here at Aerobolt the humble window packer is termed  horse shoe plastic shim  and is available in 2 lengths; 75 x 37 mm and 90 x 37 mm (L x W) in various depths 

Horseshoe shaped plastic packers are great for lightweight leveling and adjusting. They are made of high quality polypropylene which means great compression strength and flexibility. Colour coded gauges across the entire range helps you easily identify the required size - hassle-free selection. 

Rectangular shape shims for heavy weight applications

Engineered Shims for heavy duty applications. Two sizes; 100 x 75 mm and 150 x 100 mm (L X W) in various depths

These plastic shims are ideal for heavy loads like precast tilt-up concrete panels. Our plastic shims are Australian made with a 20-ton weight rating and tested in accordance with ASTM 695 and comply with AS 3850. Colour coded gauges across the entire range helps you easily identify the required size - no fuss shims with a distinct skid surface for better traction. 

How do I select the correct shim?

When considering selection you will need to look at; materials, size, shape, and compression strength. Here we list the important criteria to consider prior to making a final decision.

Shim Material.

Traditionally, shims have been made of timber or metal because these materials are easily shaped and often found as scrap on jobsites. Timber is often used in timber framed construction and cabinet works, but it is subject to crushing and rot. Steel is the material of choice in many steel projects but can lead to rust if not handled correctly.

Purpose-made plastic shims have made a place for themselves in the fast-paced construction sector. Requiring little or no shaping, and available in consistent thicknesses and material properties, plastic shims save time and money. As plastic can sometimes be stronger than timber, more dimensionally stable than steel, and resistant to moisture and microbes, it it often the material of choice.

Plastic Packers Size.

The most important property of shims is their ability to separate and adjust. The shim’s thickness is selected according to the depth of the space it is intended to maintain. Shim should be sized to fit entirely within the joint, behind the finish materials, and without interfering with any sealant that may be installed afterwards.

Shim Shape.

Rectangular shims are used for simple conditions where spaces will be later filled with a cement mix or sealant, such as tilt-up concrete panels. Horseshoe or U-shapes on the other hand, fit around bolts and can be useful for many lightweight applications.

Plastic Shim & Packer Compressive Strength.

You should select your plastic shims or packer based on the compression strength that can be expected from the application. Australian made plastic shims can withstand weight up to 20 tons whilst the horseshoe shaped plastic packers are ideal for lightweight applications.

Vermin and Decay Resistance.

Plastic shims can remain in place indefinitely, unlike timber. Plastic structural shims do not rot or decay.

Ease of Use.

Shims are easy to use for various reasons. For example, shims are frequently color-coded by thickness, simplifying and speeding installation and inspection in the field. Furthermore, there is an opportunity for some plastic shims to be stackable.

Frequently Asked Plastic Packer Questions (FAQ Section)

What type of plastic are shims?

Shims are made of durable polypropylene material that can withstand up to all sorts of conditions without compressing. Polypropylene is waterproof and will not absorb moisture in the same way as timber does or rust the way certain metals do if they are not treated correctly.

What are the plastic packer sizes and gauges?

Plastic shims and packers come in thicknesses ranging from 1 mm up to 20 mm in a range of rectangular and horseshoe shapes. You will find each thickness is colour coded for easy identification with colours varying from black, green, yellow to white and pink.

Are all plastic packers and shims weights rated to 20-tons?

Not all plastic packers are rated to 20 tons because there are numerous applications that do not warrant a 20-ton rating. Here at Aerobolt, we provide clear distinction between the window packers for lightweight applications and the heavy-duty 20-ton plastic shims. The 20-tons shims comply with all necessary standards of the ASTM D695 and AS 3850-2003 to ensure that they provide adequate compression strength.

Which trades use plastic shims?

Plastic shim applications are unlimited. The main trades include; all facets of carpentry & joinery from timber frames through to kitchen cabinets, block & brick laying, cladding, flooring, precast-concrete panels, stone masonry, wall & ceiling lining and so much more.

Can you trim, drill or nail plastic packers and shims?

Yes, you can. On top of all the other benefits, you can trim, drill or nail packers and shims easily when they are made from plastic. Being able to perform these tasks without hassle, expands the usability of shims and packers, some even come with holes and teeth to stretch their usability.

Can plastic shims and packers be exposed to sunlight?

Plastic shims and packers should not be exposed to sunlight. They are designed to be hidden and are not sunlight stable.

Can you assist with shim selection?

Shim selection can be tricky, the nature of the project and your requirements are important. The Aerobolt team can assist with the selection.

Do you deliver throughout Australia?

Yes, we can deliver Australia wide through our network team of courier companies. In Sydney we offer our customers same day delivery if you order before 10.00am, otherwise delivery is next day. Deliveries to major cities such as Melbourne, Brisbane including regional South Eastern Australia are either next day delivery or 2 days turnaround.

Plastic Shim and Packer Summary

Plastic shims and packers have 101 uses on building sites from the traditional residential home to the modern office block through to the precast concrete panel warehouse. Plastic packing shims are ideal for both heavy-duty and lightweight applications and unlike timber or metal they do not deteriorate over time.

At the conclusion of this blog, it is evident that plastic packing shims are an important component of the construction industry. Here at Aerobolt we can assist with all your shim and packer requirements, plus so much more including rivets, nutserts, screws, sealant, tools etc. Simply contact us on 02 9755 3747 or email. * Plastic shims and packers should not be exposed to UV light.

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