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When a drawing says "Class 2 FCR", it's pointing at the VicRoads classification system. The class describes quality, not size. Class 1 and 2 are fully crushed rock with tight limits on grading and plasticity, used as base course directly under the surface. Class 3 is the standard sub-base. Class 4 is the economical lower layer and select fill. The number after it (20mm or 40mm) is the largest stone in the mix, so "Class 3 40mm" means sub-base quality rock with stones up to 40mm.

Then come the modifiers. Wet mix means the rock arrives at the right moisture to compact immediately. CT (cement treated) means 1 to 4 percent cement was blended in at the plant, and the clock starts when it's mixed. CC means crushed concrete, the recycled equivalent that's accepted by most specs and cheaper. NDCR is rock that hasn't been tested to a class, fine for tracks and fills that don't carry an engineered pavement.

Water and sewer assets in Victoria are built to the WSAA national codes: WSA 03 for water supply and WSA 02 for sewerage. In metro Melbourne, the three retail agencies (Greater Western Water, South East Water and Yarra Valley Water) work together as MRWA and publish their own editions of those codes, plus the MRWA Backfill Specification 04-03 that governs how the trench above the pipe gets filled and compacted. Regional agencies like Goulburn Valley Water publish supplements on top of the same framework.

The trench has two zones and they're treated differently. The embedment zone (bedding under the pipe, haunch beside it, overlay above it) takes certified material: WSA PS 361 fine crushed rock, PS 362 10mm rock, or PS 368 recycled sand. The trench fill zone above it follows the backfill spec, with tighter rules under roads and driveways than under a nature strip. Buy embedment with the compliance certificate, because the inspector will ask.

Gas networks run to their own rulebook: AS/NZS 4645 for distribution networks and AS 2885 for high-pressure transmission pipelines. In Victoria the major networks are operated by companies like APA Group, Multinet and AusNet, with Energy Safe Victoria as the safety regulator. The materials story is simple but strict: gas pipe gets padded with clean sand or fine aggregate that is free of sharp stones and debris, because a single point load on a PE gas main is a future leak.

Two non-negotiables before anyone digs near gas. Lodge a Before You Dig Australia request (free, byda.com.au) and get the asset plans. And if you're working within the network operator's easement or near a transmission line, their permit-to-work process applies, including hand digging within the no-go zone. The network's standards override anything generic, so when in doubt, ask the operator.

Buried cables have a problem rock and water pipes don't: heat. A cable's rating assumes the ground around it carries heat away, and ordinary backfill full of air voids acts like a blanket. That's why HV cable trenches specify thermal sand, graded so the particles pack dense and conduct heat, with the thermal resistivity certified by test. Use the wrong sand around an HV feeder and the asset owner will make you dig it back up.

For everyday LV conduits the rules come from AS/NZS 3000 (depth of cover by location category, orange conduit, marker tape) and the local distributor's service rules: Powercor, CitiPower, AusNet, Jemena or United Energy depending where you are in Victoria. Energy Safe Victoria regulates the lot. Same golden rule as gas: BYDA plans before the bucket goes in.

A road is a layer cake, and every layer has a job. From the bottom: subgrade (the natural ground, sometimes improved), capping (seals and bridges a soft subgrade), sub-base (usually Class 3, the volume layer), base (Class 1 or 2, the strength layer), then the wearing surface (asphalt, spray seal or concrete). Each layer spreads load over the one below it, which is why the expensive material sits near the top and the economical material near the bottom.

Compaction is the whole game. Material gets placed in lifts (layers of controlled thickness), watered to optimum moisture and rolled until it hits the specified density, then tested before the next lift goes down. This is why wet mix is worth ordering and why a stalled truck can stall a whole crew. VicRoads' standard sections (812 for crushed rock products, 204 for earthworks) are the documents your superintendent is quoting from.

Concrete is ordered by three numbers. Strength in MPa (20 MPa for paths, 25 to 32 for driveways and slabs, 40 and up for structural work), slump in millimetres (how wet and workable it arrives; 80 to 100 is typical), and aggregate size (20mm standard, 14mm or 10mm for tight reinforcement or pumping). AS 1379 governs the supply and testing of it all. Special mixes exist for a reason: blinding concrete for clean working surfaces, no-fines for drainage, slurry for void fill, exposed aggregate for the architect.

The thing nobody tells juniors: scheduling is a material property. Concrete starts setting when it's batched, so the spacing of trucks has to match the crew's placing rate. Too fast and trucks queue while concrete ages on the back. Too slow and you get cold joints. The same logic applies to stabilised sand and cement treated rock, which is exactly why we built live truck tracking.

"Topsoil" on a drawing can mean four different products, and the spec tells you which. AS 4419 is the Australian Standard for landscaping soils (pH, salinity, organic matter, all batch tested). VicRoads Section 720 covers topsoil for road reserves and batters. School projects run on the VSBA's Building Quality Standards Handbook, which calls up landscape requirements for Victorian government schools. Melbourne Water has its own soil specs for waterway corridors. Each one wants test certificates, so order spec soil as spec soil, not "some topsoil".

For unspecified work the everyday menu is: screened topsoil for lawns and reinstatement, garden blends with composted organics for planting, and sandy loam as the turf underlay that levels true and drains. Structural soil (a stone and soil matrix) is its own animal for street trees under pavement, and lightweight blends exist for rooftops and podium decks where the engineer is counting kilograms.

Under play equipment, the ground is safety equipment. Loose-fill softfall (certified playground mulch) has to meet AS 4422, the impact attenuation standard, at the fall height of the equipment above it, and it has to be installed at the certified depth, usually around 300mm after settlement. Ordinary garden mulch is not softfall, no matter how soft it looks, because certification is the whole product.

The details that catch people: softfall compacts and migrates, so design includes containment edging and a top-up schedule. Drainage under the softfall matters as much as the softfall, which is where clean aggregate layers come in. On school projects the VSBA handbook adds its own requirements around play areas. Buy certified, keep the certificate with the handover docs.

The moment soil leaves your site it becomes industrial waste under Victoria's Environment Protection framework, and it has to be classified before it moves. The ladder runs from fill material (clean, lowest risk) up through Category D, C, B and A as contaminant concentrations rise, plus a separate stream for soil containing asbestos only. The category determines where the soil can legally go and what it costs to get rid of, which is why a soil report before excavation is money well spent.

Categorised soil is priority waste: transport gets tracked through EPA's Waste Tracker system and only licensed facilities can receive it. "Mixed fill" in practice means fill with minor inert mixings like brick and concrete, and tips price it differently from clean fill, so don't let the terms blur. Reusing soil on the site it came from, or under an EPA declaration of use, can avoid the disposal chain entirely. When in doubt, classify first and dig second.

Knowing your trucks saves real money, because cartage is priced per movement. As a rule of thumb in Victoria: a rigid tipper carries roughly 6 to 13 tonnes depending on axles, a truck and dog (rigid towing a dog trailer, the workhorse of quarry cartage) moves about 24 to 26 tonnes a trip, and a semi tipper runs similar or a touch more with a longer, less nimble footprint. Fewer big trips beats many small ones, if your site can take the big truck.

That "if" is the part to check before ordering: gate width, turning room, firm level ground to tip on, and overhead clearance, because a tipping body needs roughly 7 metres of clear air and power lines don't negotiate. A truck and dog needs space to uncouple or run through. Legally, mass limits and fatigue sit with the NHVR, and under Chain of Responsibility everyone who influences the transport task (including whoever orders the truck) shares the duty. Tell your supplier the access constraints and the right truck turns up.