The Easy Way To Order Bulk Polystyrene Nationally In South Africa

Johannesburg (Gauteng)

011 678 5626

Cape Town (Western Cape)


021 200 5926

Durban (Kwazulu-Natal)

031 940 7056

East London & PE

087 095 3259

National Sales


PolyVoids - Polystyrene Sheets & Blocks For Raising Concrete Slabs

Supplied Nationally In South Africa
In stock
Product Details

Polystyrene Void Formers - For Raising Concrete Floor Slabs


Fire-Retardant PolyVoid Formers are a super cost-effective way to raise the level of existing concrete slabs.

Often engineers and building contractors need to raise the level of an existing concrete slab, quite considerably, without significantly increasing the design loads (weight) on the existing concrete slab. In these cases, our PolyVoid Sheets & Blocks, are the perfect product because they are both lightweight and have significant compressive strength allowing them to easily raise the slab and carry the weight of the new reinforced concrete slab that will be cast on top of the void-formers.

In the pictures above, our PolyVoid formers are being used to raise an existing concrete slab by 1m, on the Nelson Mandela Children's Hospital Project in Gauteng. A new concrete slab was then cast on top of the void-formers so that the new concrete slab level could tie in with the new building structure.

We specialise in cost-effective bulk polystyrene void-former products so check out our google service reviews and when you are ready just order your polystyrene void-formers nationally online!

New Concrete Slab Thickness

Once the polystyrene void-formers have been placed a new concrete slab must be cast. The minimum thickness of this new concrete slab needs to be 80mm. It also needs to be a fully reinforced concrete slab.

Order Collections & Deliveries

Depending on the size of your order and location, we will deliver or you can self-collect from any of our national distribution centers located in:

  • Strydompark in Gauteng
  • Philippi in Western Cape
  • Clairwood in Kwazulu-Natal
  • Wilsonia in East London or
  • Neave Industrial in Port Elizabeth

Our online ordering platform deals with local deliveries close to our national distribution centres. If your project is far away from these distribution centres, you can always request a national delivery quote via email. Please note that these standard sheets and blocks will not fit in a normal vehicle.

Order lead time is currently 3 to 7 working days for cutting and delivery, once payment reflects in our bank account. This lead time excludes public holidays and weekends. If you need product faster please call us so that we can try and assist.

What size sheets or blocks should you order?

Time and time again we get requests for special blocks sizes to be cut exactly to fit the area. This is not the cost effective way to order PolyVoid Formers. The cost effect way to order PolyVoid Former is to order manageable sized standard sheets that can then simply be cut by hand on site and placed on the concrete slab. This way there is very little or no polystyrene wastage making it very cost-effective.

If you need any assistance with projects of this nature we are more than happy to give advice and try and find the most cost effective solution for you.

What density polystyrene do you need?

Density is very important when raising existing concrete slabs. It is important for a number of reasons:

  • The higher the density the more expensive the product
  • The higher the density, the higher the compressive strength (loading requirement)

Your structural engineer will have to specify the correct density!

As with any structural design, your engineer will have to specify the density of polystyrene based on their design and the actual design loading requirement specific to the project. The structural engineer will need to base their design on the compressive strength properties of the polystyrene as seen in the table below. We manufacture polystyrene in the following densities.

  • Low Density (X-Grade) - 12 kg/m3
  • Medium Density - 15 kg/m3
  • High Density - 20 kg/m3
  • Highest Density - 24 kg/m3 to 30 kg/m3

Polystyrene Compressive Strength Table:

Here is a properties table for the various polystyrene densities.

Density Compressive Stress Cross-Breaking Strength Safe Working Load
Low Density 60 kPa @ 10% compression 80 kPa 15 kPa @ 1% compression
Medium Density 65 kPa @ 10% compression 100 kPa 17 kPa @ 1% compression
High Density 110 kPa @ 10% compression 150 kPa 45 kPa @ 1% compression
Highest Density 160 kPa @ 10% compression 205 kPa 70 kPa @ 1% compression

Manufacture & Supply:

Our PolyVoid Formers are manufactured locally in South Africa and distributed nationally from our regional factories in:

  • Johannesburg
  • Cape Town
  • Durban
  • East London &
  • Port Elizabeth

We also export our polystyrene sheets, blocks and other products to certain countries in Africa, based on order volumes.

Payment Methods

  • Credit Card
  • Instant EFT
  • Invoice & EFT
  • Submit For Review

About Polystyrene Product Company (Pty) Ltd

Polystyrene Product Company, established nationally in South Africa in 2016, is a well known & respected bulk national supplier of polystyrene sheets, blocks, insulation, extruded polystyrene ceilings & void-formers in South Africa & for export.

Since 2016, we have supplied polystyrene to over 14000 customers nationally in South Africa, Botswana, Mozambique, Zambia, Zimbabwe & Mauritius. We have also supplied bulk polystyrene to many of the biggest construction projects in South Africa.

We are the #1 National Online Ordering Platform For Bulk Polystyrene In South Africa, making it easier and faster for architects, builders, bulk buyers & the general public to order polystyrene online in SA.

CO. Reg Number: 2016/072709/07

VAT Number: 4220273447

National Sales & Logistics (Johannesburg) 011 678 5626

Cape Town Sales 021 200 5926

Durban Sales 031 940 7056

East London & PE Sales 087 095 3259

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Polystyrene Product Company

Your Trusted Specialists In Bulk Polystyrene For Concrete Floor Insulation, Cavity Wall Insulation, Concrete Roof Insulation, Thermal Ceilings & Void-Former Applications

National Sales & Head Office


Unit 8, Lower Ground Level, Commercial City, Tungsten Rd, Strydompark, Randburg, 2194

VAT Number: 4220273447

CO. Reg Number: 2016/072709/07

Main Office Number:

011 678 5626


Main Email:

Recently Supplied Projects

Cape Town Convention Center Extension Concrete Roof Insulation Project

1400m2 of 120mm Extra-High Density Concrete Roof Insulation (PolyRoof Insulation) Laid On Top Of Torch-On Waterproofing With Paving Overlay

Hydroboard Insulation_edited.jpg
PolyVoid - Structural Fill Blocks.jpg

Nelson Mandela Children's Hospital Raised Slab Project 

3000m2 of 50mm Extra-High Density Concrete PolyVoid Fillers To Raise An Existing Concrete Slab By 1m. Extra-High Density Polystyrene Has Incredible Compressive Strength Properties.


Let's Explore Your Polystyrene Building Requirements Together!