Resin Bound Aggregate vs Exposed Aggregate Driveways in Sydney
Surface Master Australia | | 9 min read
Understand resin bound aggregate, how it differs from exposed aggregate concrete, and what to check before choosing a Sydney driveway surface.
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What Is Resin Bound Aggregate?
Resin bound aggregate, also called resin bound gravel or resin bound paving, is natural stone mixed with a resin binder before it is trowelled over a prepared base. It is a bound surface rather than loose gravel. Exposed aggregate concrete is a different system: stone is embedded in a concrete slab and revealed at the surface.
The useful comparison is the complete driveway, not just the visible stones. Resin bound may suit an overlay on a sound existing base; exposed aggregate is normally assessed as a new concrete pour. With either option, base condition, falls, access and the intended traffic need to be checked before a written quote.
Resin Bound vs Exposed Aggregate: At a Glance
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Compare the base, drainage, finish and quote scope of two driveway surfaces
| Decision | Resin bound aggregate | Exposed aggregate concrete |
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| Existing driveway | An overlay may be suitable if the concrete or asphalt base is sound and stable. | A new concrete pour needs its own base, forming and curing scope. |
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| Drainage | The surface has voids, but drainage through the pavement depends on the layers below. An overlay does not make sealed concrete permeable. | Water runs off the concrete, so falls and drainage outlets need to be planned. |
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| Finish and upkeep | A trowelled stone finish; keep the surface free of silt and clean spills promptly. | A textured concrete finish; discuss cleaning and the specified sealer's maintenance schedule. |
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| Comparing quotes | Confirm base repairs, drainage, edging, binder, aggregate and traffic suitability. | Confirm excavation, base work, concrete specification, forming, finish and sealing. |
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For a potential overlay, review our resin driveway assessment and installation service. For paths, pool surrounds or a broader comparison, see the resin bound paving guide to cost, base and drainage. Surface Master installs resin bound; this article compares the options so you can assess the scope of each quote.
How They're Installed: Key Differences
Exposed aggregate concrete is a wet concrete product. It is poured as a conventional concrete slab, then treated with a surface retarder to prevent the top layer of cement from setting. After an appropriate curing period, the retarder is washed off with a high-pressure hose, exposing the aggregate (stone, pebble, or glass) beneath. The result is a textured surface with the aggregate permanently embedded in the concrete matrix.
Resin bound paving is an overlay system. A prepared base — either new or existing concrete or asphalt — is overlaid with a trowel-applied mix of natural aggregate and clear UV-stable resin. The resin coats each aggregate particle and bonds them together and to the base. The result is a smooth, permeable surface with a distinctive natural stone appearance.
Key installation differences:
- Exposed aggregate requires a new concrete pour and full cure time (typically 28 days before sealing). Resin bound can be installed over existing concrete or asphalt with appropriate surface preparation.
- Resin bound is faster to install when going over an existing base — typically 1-2 days for a residential driveway versus 5-7 days for a new concrete pour and cure cycle.
- Resin bound requires a sound, stable base — any movement in the base will reflect through to the surface.
Drainage Depends on the Whole Driveway
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This is arguably the most significant functional difference between the two systems. Exposed aggregate concrete is impermeable — water runs off the surface, requiring adequate falls to drainage channels. In Sydney's suburban environment, this often means directing water to the street or neighbouring properties, which can create stormwater management issues.
The resin bound mat itself passes water through the voids between the coated stones. Whether the pavement drains, though, depends on what sits underneath it. On a new permeable build-up — typically 100–150mm of compacted crushed sub-base under a permeable binder course, with the crushed 4/20mm aggregate and minimum 30% voids ratio that BS 7533-13 specifies for permeable pavements — water passes through the surface and away into the base. That gives you:
- No puddles or surface water accumulation, as long as the full build-up drains and the surface is kept free of silt
- Reduced stormwater runoff — significant on larger driveways
- Fewer surface drainage channels than an impermeable surface needs
- A surface that can form part of a SuDS-style approach where a Sydney council asks for one
The important caveat, and the one most quotes gloss over: laying resin bound over an existing sealed concrete slab does not make that slab permeable. Water still passes the surface, but it then has to reach a drain. On an overlay job the falls, channels or edge drainage are designed as part of the scope, and a contractor who does not raise that has not looked at your drainage.
For pool areas, the same logic applies. Where the build-up drains, water clears the surface rather than sitting around the pool edge — which is why resin bound pool surrounds suit wet barefoot traffic. See the Cronulla pool surround project for how the falls and edge detail were handled on a real site.
Maintenance Requirements
Exposed aggregate concrete requires periodic sealing (every 3-5 years) to maintain surface protection and colour vibrancy. Without sealing, the aggregate becomes dull, the surface becomes more porous, and moss and algae growth accelerates in shaded areas. High-pressure cleaning is typically required annually in Sydney's climate, especially in coastal or shaded locations.
Resin bound paving requires minimal maintenance. The smooth surface does not harbour moss or algae as readily as exposed aggregate. Annual sweeping and occasional rinsing with a garden hose is sufficient for most residential applications. Resin bound does not require periodic sealing as the resin binder itself provides UV protection. However, areas subject to chemical spills (oil, fuel) should be cleaned promptly as some resin binders can be affected by petroleum products.
Longevity and Lifespan
Both systems have long lifespans when installed correctly, but failure modes differ:
- Exposed aggregate concrete: Typically 20-30+ years before major structural issues. The main degradation issues are surface seal failure (leading to aggregate popout), cracking from ground movement, and surface efflorescence in some Sydney soil conditions. Resealing every 3-5 years extends the surface appearance lifespan significantly.
- Resin bound paving: 15-25 years in residential applications with quality resin binders. The main degradation risk is UV degradation of the resin binder (yellowing or brittleness) if a non-UV-stable resin is used — this is why specifying UV-stable resin is non-negotiable for Sydney's high UV environment. Quality installations from reputable contractors use polyurethane or UV-stable aliphatic resin binders.
Cost Comparison
Short answer: resin bound is the more expensive option, by roughly double. For a 50sqm Sydney driveway, exposed aggregate runs $4,000–$6,500 and resin bound runs $9,000–$14,000.
| Option | Rate | 50sqm driveway | What it covers |
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| Exposed aggregate concrete (new pour) | $80–$130/sqm | $4,000–$6,500 | Base preparation, forming, concrete supply, retarder treatment, seal |
| Resin bound paving (supplied and installed) | $180–$280/sqm | $9,000–$14,000 | Base preparation, edge restraint, UV-stable binder and aggregate, laying |
We would rather be straight about this than bury it: resin bound is a premium surface and it is priced like one. If the decision is purely about the cheapest way to get a presentable driveway, exposed aggregate wins and it is not close.
What the extra buys is a different set of properties, not a nicer version of the same thing — permeability where the base supports it, a seamless finish with no loose stone, a cooler surface underfoot, and no resealing cycle. Exposed aggregate needs resealing every 3–5 years, so some of the gap closes over a 20-year life, but it does not close entirely. Choose resin bound because you want those properties, not because you expect it to come out cheaper.
Within the resin bound band, base condition is the main lever: overlaying a sound existing slab sits at the lower end, while a new excavated base with sub-base and drainage sits at the upper end. These are planning ranges, not quotes — the full breakdown and what moves it sits on the resin bound paving page.
Can You Lay Resin Bound Over an Existing Concrete Driveway?
Short answer: yes, provided the slab is sound, stable and not actively moving. Resin bound is an overlay, so it takes its structural behaviour from whatever is underneath. A crack that is still moving will reflect through the new surface within a season or two, and a slab with rocking sections will keep rocking under a 20mm mat.
What a proper assessment looks at before quoting an overlay: active versus dormant cracking, slab movement at joints and edges, surface contamination and laitance, existing falls, and where water currently goes. Sound slabs are prepared and overlaid; slabs that fail the assessment need the base addressed first, which is what moves a job from the lower end of the $180–$280/sqm band toward the upper end. The resin bound driveway page sets out the sequence, and the Manly driveway project shows a job where drainage had to be corrected before the surface went down.
Resin Bound vs Resin Bonded: Not the Same Product
Short answer: resin bound mixes the aggregate through the resin before laying, giving a smooth, seamless mat with no loose stone that can drain through when the base allows. Resin bonded scatters dry aggregate onto a resin-coated surface — more textured and higher grip, but effectively sealed, and the surface stone can work loose over time.
The distinction matters when you are comparing quotes, because the two are sometimes priced against each other as if they were interchangeable. They are not: only one of them is permeable, and only one of them gives you a seamless surface suitable for prams, wheelchairs and trolleys. Surface Master Australia installs resin bound.
UV Stability in Sydney's Climate
Sydney's UV index is consistently high — one of the highest in the world for a major city. This has direct implications for outdoor surface selection. Exposed aggregate concrete is essentially UV-stable by nature (cement and stone don't degrade from UV), though the sealer coat will degrade and require periodic renewal.
Resin bound paving requires UV-stable resin binders — specifically, aliphatic polyurethane or similar UV-resistant chemistry. Aromatic resins (the cheaper option) will yellow and degrade within 2-3 years in Sydney's UV environment. Always confirm with your contractor that the resin system specified is UV-stable and suitable for Sydney's climate.
Pool Safety Considerations
For pool surrounds, assess the installed system and site conditions rather than assuming a surface material is safe in every setting:
- Slip resistance: Grip comes from the aggregate size and texture, and is classified under AS 4586 on the installed surface rather than on the product in general. Ask your contractor to state the target classification for wet barefoot traffic in the written scope.
- Barefoot comfort: Review the selected aggregate texture and colour on a sample before committing to the finish.
- Drainage: Check the whole build-up, falls and discharge point. Surface permeability alone does not guarantee that water will clear the pool edge.
- Chemical resistance: Confirm that the specified binder and installed system are suitable for the pool chemicals and cleaning products in use.
FAQs
Is resin bound paving permeable?
The resin bound surface has voids that let water pass between the coated stones. Whether the full pavement drains depends on the base and sub-base below and where water can discharge. An overlay on sealed concrete does not make that concrete permeable; falls, channels or edge drainage still need to be assessed. Exposed aggregate concrete also needs planned falls and drainage.
How long does resin bound paving last in Sydney?
A quality resin bound installation using UV-stable polyurethane or aliphatic resin binders typically lasts 15-25 years in residential applications in Sydney. UV stability is critical — cheaper aromatic resin binders will yellow and degrade within 2-3 years in Sydney's high-UV environment. Always confirm the resin specification with your contractor.
Is resin bound paving suitable around swimming pools?
Resin bound may be suitable for pool surrounds when the installed system is specified for wet barefoot use, pool chemicals and the site drainage. Confirm aggregate texture, the required slip classification, binder compatibility and edge details in the written scope. Surface permeability alone is not a guarantee against pooling or slipping.
Which driveway surface is better for Sydney's climate?
There is no single best option for every Sydney driveway. Compare the existing base, drainage, traffic, finish and maintenance requirements. Resin bound needs an appropriate UV-stable binder and a stable base; exposed aggregate needs a suitable concrete and sealing specification. Ask each installer to explain how their proposed system addresses the conditions on your site.
What is the difference between resin bound and resin bonded surfacing?
Resin bound and resin bonded are different products. Resin bound mixes the aggregate through the resin before application, creating a smooth, seamless mat with no loose stone that can drain through where the base allows. Resin bonded (also called resin spray or scatter coat) applies resin to the surface and scatters aggregate on top: it is more textured and higher grip, but it is effectively sealed and the surface aggregate can work loose over time. Surface Master Australia installs resin bound (the fully-encapsulated system) only.
