Turf Underlay Supply Across Wollongong and the Illawarra
We supply turf underlay product across Wollongong and the full Illawarra region — covering Shellharbour, Kiama, Dapto, Figtree, Fairy Meadow, Balgownie, Thirroul, Corrimal, Albion Park, Unanderra, and surrounding suburbs. Whether the project is a new residential installation, a commercial surface, a playground system, or a replacement of degraded underlay in an existing installation, we carry the correct product and can advise on specification and quantity for any synthetic grass application across the region.
The Illawarra’s clay-heavy inland soils and coastal salt-air conditions each present specific challenges for base preparation that affect underlay performance. Clay soils that retain moisture require an underlay with superior drainage capacity to prevent moisture accumulation beneath the turf. In contrast, coastal installations exposed to salt air require materials with appropriate resistance to salt environment degradation. These are the local conditions we factor into every underlay recommendation we make for Wollongong and Illawarra projects — ensuring the product specified is matched to the conditions it will perform in for the life of the installation.
Foam Underlay for Residential Synthetic Grass Wollongong
Foam underlay is the standard product for residential synthetic grass installations — a polyethylene foam product supplied in rolls that is laid across the prepared base before the turf is positioned and fixed. For Wollongong homeowners installing synthetic grass in a backyard, front yard, or entertaining area, foam underlay is the product that transforms the feel of the finished surface from functional to genuinely comfortable underfoot.
We supply both closed cell and open cell foam underlay for residential applications across Wollongong and the Illawarra. Closed cell foam underlay provides superior moisture resistance and dimensional stability — maintaining its thickness and cushioning properties over the life of the installation without absorbing water or compressing permanently under load. Open-cell foam underlay offers a softer initial feel but requires careful product selection to avoid moisture retention issues in the Illawarra’s high-rainfall, high-humidity conditions.
For residential backyard and front yard applications where underfoot comfort is a primary consideration alongside drainage performance, foam underlay is our standard recommendation across the full range of Wollongong installation contexts.
Commercial Grade Turf Underlay Wollongong
Commercial synthetic grass installations operate under conditions that standard residential foam underlay is not engineered to handle. Heavy concentrated foot traffic, repeated loading across high-use zones, and the expectation of a surface that maintains its performance characteristics over a significantly longer service life all require underlay products specified to commercial-grade performance standards.
High-density foam underlay and composite underlay products that combine foam cushioning with drainage cell structure are the appropriate specification for commercial applications — maintaining their thickness, cushioning properties, and drainage performance under repeated heavy loading that would compress and degrade a standard residential product within a fraction of its expected lifespan.
We supply commercial-grade turf underlay to businesses, councils, schools, sporting facilities, and institutional operators across Wollongong and the Illawarra. Commercial underlay specification is a distinct product category — not simply a heavier version of residential underlay — and we advise on the correct product for each commercial application based on the specific traffic loading, surface use, and performance requirements of the project.
Choosing the Right Underlay Thickness for Your Installation
Foam underlay for residential synthetic grass installations typically ranges from seven to twelve millimetres in thickness, and the thickness selected directly affects the underfoot feel of the finished surface. Thicker products produce a noticeably softer, more cushioned feel that is particularly valued in entertaining areas, children’s play zones, and pet use areas where the surface sees regular bare-foot contact and extended time spent sitting or lying on the lawn.
Key considerations when selecting underlay thickness:
- 7mm foam underlay — suitable for standard residential applications where a modest comfort improvement over a compacted base is the primary requirement
- 10mm foam underlay — the most common residential specification, balancing underfoot comfort with dimensional stability and drainage performance
- 12mm foam underlay — the premium residential option for entertaining areas, children’s play zones, and pet areas where a soft, luxurious surface feel is the priority
Thickness selection should also account for the installation context. In areas where the underlay meets hard boundaries — paving edges, pool coping, or wall bases — thicker products require precise trimming to avoid compression against the boundary that creates a raised edge telegraphing through the finished turf surface.
Drainage Cell Underlay for Balconies and Rooftop Installations
For synthetic grass installations on balconies, rooftops, and elevated courtyards, drainage cell underlay is not a product enhancement — it is the correct technical specification for the application. Standard foam underlay is not appropriate for these surfaces. Where the existing surface has defined drainage points and water must move efficiently across the full installation area to reach them, the underlay system must create a continuous, unobstructed drainage cavity beneath the turf.
Drainage cell underlay — also referred to as egg-crate or flow cell underlay — is a rigid or semi-rigid plastic grid product with an open structure that elevates the turf assembly above the surface beneath, channelling water efficiently to drainage points regardless of where it falls across the installation area. For balcony and rooftop installations where ponding water presents both a safety risk and a potential source of waterproofing damage, this is the product that protects the surface beneath while maintaining the drainage performance the installation requires.
We supply drainage cell underlay for elevated surface applications across Wollongong and the Illawarra, and can advise on the correct specification for any balcony or rooftop project.
Shock-Absorbing Underlay for Playgrounds and Sports Turf Wollongong
Shock-absorbing underlay for playground and sports turf applications performs a fundamentally different function from residential foam underlay. In these installations, the underlay is not a comfort enhancement — it is a safety component that forms part of the certified surface system used to demonstrate compliance with AS 4422 for playground surfacing and relevant sports surface standards.
Shock-absorbing underlay products are engineered to defined HIC and Gmax performance ratings — the impact measurement metrics used in playground and sports surface compliance testing. The underlay must be installed at the correct thickness and density to achieve the critical fall height rating that the surface system is certified to deliver. Selecting an underlay product based on thickness or price alone, without reference to its certified performance rating, produces a surface that may not meet the compliance requirements the installation is intended to satisfy.
Key applications for shock-absorbing underlay across Wollongong and the Illawarra:
- School playground synthetic turf installations
- Childcare centre soft fall surfaces
- Community sports fields and training facilities
- Institutional playground operators requiring documented AS 4422 compliance
We supply certified shock-absorbing underlay products with the performance documentation that schools, childcare centres, and institutional operators need to demonstrate compliance.
Calculating Your Underlay Quantity
Foam underlay is supplied in rolls of varying width and length, and ordering the correct quantity for a specific installation area requires the same planning as ordering turf. Roll width alignment, join placement, and wastage from cuts around irregular boundaries all affect the total product required — and underordering mid-project creates delays that a correctly calculated initial order avoids entirely.
Key factors that affect underlay quantity calculation:
- Installation area dimensions — total square meterage of the surface to be covered, accounting for any irregular boundaries or cutouts
- Roll width alignment — positioning roll widths to minimise joins and reduce offcut waste across the installation area
- Join placement — underlay joins must be offset from turf joins above to prevent alignment that creates a visible or tactile line in the finished surface
- Boundary cuts — allowance for material lost to trimming at walls, paving edges, and pool coping
We calculate the correct underlay quantity for your specific project and can supply product cut to order where project dimensions allow — minimising waste and simplifying on-site installation across Wollongong and the Illawarra.
Frequently Asked Questions — Turf Underlay Supply Wollongong
Turf underlay is not mandatory for every installation, but it meaningfully improves the comfort, drainage performance, and longevity of the finished surface. For residential entertaining areas, children’s play zones, and pet areas, we recommend underlay as a standard component of the installation system
Closed-cell foam underlay resists moisture absorption and maintains its thickness and cushioning properties over the life of the installation. Open cell foam offers a softer initial feel but can retain moisture in high-rainfall, high-humidity conditions like those common across the Illawarra.
Ten millimetres is the most common residential specification, balancing underfoot comfort with dimensional stability and drainage performance. Twelve millimetre underlay is the premium option for entertaining areas and children’s play zones where a softer surface feel is the priority.
No. Balcony and rooftop installations require drainage cell underlay — a rigid plastic grid product that creates an unobstructed drainage cavity beneath the turf. Standard foam underlay restricts water movement on elevated surfaces and can contribute to ponding and waterproofing damage.
Drainage cell underlay is a rigid or semi-rigid plastic grid product that elevates the turf assembly above the surface beneath, channelling water efficiently to drainage points. It is the correct specification for any synthetic grass installation on a balcony, rooftop, or elevated courtyard with defined drainage points.
Playground installations require certified shock-absorbing underlay engineered to defined HIC and Gmax performance ratings. The underlay must be installed at the correct thickness and density to achieve the critical fall height rating required to demonstrate AS 4422 compliance for the surface system.
Whether you’re a homeowner planning a residential backyard installation, a DIY installer sourcing product for a specific application, or a trade contractor supplying underlay across multiple Illawarra projects, we carry the full product range and can recommend the correct underlay specification and quantity for any synthetic grass installation in the region.
From standard residential foam underlay through to drainage cell, shock-absorbing, pet-grade, and commercial-specification products, we supply underlay to match every installation context — with the local knowledge to factor in the specific base conditions, climate, and performance requirements of Wollongong and Illawarra projects.
Contact us today to discuss your underlay requirements, confirm the right product for your application, and get a free quote on supply and delivery across the Illawarra.
