Suspended Slab Solutions
Void Panels
EPS void formers for suspended concrete slab construction. Reduce concrete volume, manage reactive soils, and lower structural dead load — supplied Australia wide.
Up to 60%
Concrete Reduction
4 Depths
300–600mm
AS 3600
Compliant
Australia Wide
Delivery
What Are Void Panels?
Smarter Slab
Construction
Void Panels — also known as void formers or void boxes — are expanded polystyrene (EPS) blocks placed within a suspended concrete slab to create hollow voids. By replacing solid concrete with lightweight EPS, you significantly reduce the volume of concrete required, cutting material costs and structural dead load.
Void Panels are the standard solution for suspended slabs on reactive soils (Class M, H1, H2, and E), where soil movement beneath the slab must be accommodated. The void space allows the ground to move without transferring stress to the slab or the structure above.
Steel Source Australia supplies a full range of EPS Void Panels in four standard depths, with custom sizes available. All panels are manufactured to consistent dimensions for predictable structural performance and easy installation.
Why Use Void Panels
Key Benefits
Reduce Concrete Volume
Void Panels create hollow voids within the slab, significantly reducing the volume of concrete required — cutting material costs and structural dead load.
Reactive Soil Solution
Ideal for sites with reactive (Class M, H1, H2, E) soils. The void beneath the slab allows for soil movement without transferring stress to the structure above.
Engineered Performance
All Steel Source Australia Void Panels are manufactured to consistent dimensions and load ratings, ensuring predictable structural performance in every application.
Easy to Handle
Lightweight and stackable, our Void Panels are easy to transport, store on site, and position by hand — reducing labour time and crane requirements.
Product Range
Void Panel Sizes
Available in four standard depths to suit a range of structural requirements. Custom depths and widths available on request.
Void Panel 300
Residential suspended slabs on reactive soils
Void Panel 400
Residential and light commercial suspended slabs
Void Panel 500
Commercial and multi-residential suspended slabs
Void Panel 600
Heavy commercial and industrial suspended slabs
Technical Specifications
How to Install
Installation Guide
A general overview of the Void Panel installation process. Always follow your structural engineer's specific instructions and AS 3600.
Important: Void Panel layout, depth, and reinforcement must be designed and specified by a licensed structural engineer. This guide is a general overview only and does not replace engineering documentation. Always comply with your engineer's drawings and specifications.
Site Preparation
Prepare the sub-base as per your engineer's specification. Ensure the ground is level, compacted, and free of debris. Install any required termite barriers and damp-proof membranes.
Edge Formwork
Install perimeter edge formwork to the required slab thickness. Ensure formwork is level, plumb, and adequately braced to contain the concrete pour.
Bottom Reinforcement
Place bottom steel reinforcement mesh or bars as specified by your structural engineer. Ensure correct cover to reinforcement using approved bar chairs.
Void Panel Placement
Position Void Panels in the layout specified by your engineer. Panels should be placed tightly together with no gaps. Secure panels to prevent movement during the concrete pour using tie wire or approved clips.
Top Reinforcement
Place top steel reinforcement mesh or bars over the Void Panels as specified. Ensure correct cover is maintained. Install any additional reinforcement at penetrations, edges, and load points.
Concrete Pour
Pour concrete to the specified depth and finish as required. Use internal vibration carefully to avoid displacing Void Panels. Do not over-vibrate in the void panel zone.
Curing
Cure the slab as per your engineer's specification and AS 3600. Protect the slab from rapid drying, direct sun, and foot traffic until the specified strength is achieved.
Common Questions
Void Panel FAQ
Do I need an engineer to specify Void Panels?
Yes — Void Panel layout, depth, and reinforcement must be specified by a structural engineer. Steel Source Australia can supply panels to your engineer's specification. We recommend engaging a structural engineer early in the design process.
Are Void Panels suitable for all soil types?
Void Panels are most commonly used on reactive soils (Class M, H1, H2, E) where soil movement is a concern. They can also be used on non-reactive sites where concrete reduction is desired. Your geotechnical report will determine the appropriate slab design.
Can Void Panels be cut to size on site?
Yes — EPS Void Panels can be cut with a hand saw or hot wire cutter to fit around penetrations, columns, and irregular edges. Always follow your engineer's instructions for panel layout and any required modifications.
How are Void Panels delivered?
Void Panels are delivered on flat-bed trucks and are typically palletised for easy unloading. Due to their size and volume, we recommend having a forklift or telehandler available on site for unloading large orders.
Have more questions about Void Panels?
View Full FAQAustralia Wide Delivery
We deliver Void Panels to all states and territories — metro, regional, and remote. Due to the volume of Void Panels, we recommend having a forklift or telehandler available for unloading. Contact us for a delivery quote to your site.
Ready to Order Void Panels?
Get a fast, competitive quote on Void Panels delivered to your site anywhere in Australia. Call us or send an enquiry and our team will respond within 1 business day.