Datum Ground Testing Malaga · Since 2011 (08) 9000 0391 Book a test

Site classification · Perth metro

We log the ground before anybody prices the slab — bored, sampled and classified to AS 2870

Two truck-mounted rigs out of Malaga. Two holes a lot, logged to AS 1726, sampled, classified, and the report on your builder's desk in three working days.

This block, classified

MAS 2870 class

$620All up, inc. GST

ys 32 mm · 2 holes to 3.0 m

Call (08) 9000 0391 Book the rig
Since 2011 · $20M public liability Report to your builder in three working days

The ground doesn't set our fee. The number of holes and how deep we take them does — which is why the profile you pick below moves the class and the log, and leaves the price exactly where it was.

The Log

Borehole 1 of 2 · AS 1726

A borehole log drawn to depth with the strata, the water table, the sample tags and the AS 2870 class A field log sheet. Depths tick down the left in a monospaced face. A borehole column runs down the middle with the strata banded and hatched — sand, clay, gravel, weathered rock or uncontrolled fill depending on the profile chosen. The water table strikes across the hole as a dashed line where it is struck within the drilled depth. Olive sample tags hang off the side of the hole at the sampled depths. A one point seven metre surveyor figure stands on the surface beside the hole holding the vertical scale honest. At the surface on the right a laterite double-headed arrow shows the characteristic surface movement with the AS 2870 class stamped beneath it. A strip of numbered lots runs across the top with the logged lot marked.

Datum · this block

$620 · Class M

ys 32 mm · 2 holes to 3.0 m · 1 lot

On every job

  • Two holes a lot, logged to AS 1726
  • Classified to AS 2870-2011
  • Samples bagged and retained six months
  • Refusal depth and water level recorded with the date

What's under the block sets the log, the movement and the class — not the fee

Not sure? Pick the one closest to your suburb — we confirm it with the auger, and the fee doesn't move either way.

How deep we take them the frame zooms to fit; the surveyor stays 1.7 m

The design suction change depth in Perth is 1.8 m — going deeper prices the rig time and the footing design, it does not change your class.

How many lots on the one visit, one mobilisation

1Lot

First lot $620, every extra lot on the same visit $410.

Fill-depth investigation extra holes and sampling to prove how deep the fill goes

Where the block is travel is one flat charge for the visit, outside the per-lot rates

    Book this test

    Prices include GST. Report to your builder in three working days.

    Six things we charge for

    Holes, depth, lots and travel. That's the whole price list.

    Prices include GST and cover the boring, the logging, the sampling, the classification to AS 2870-2011 and the report. Owner-builders, renovators and small builders with a street of lots to get away — same rates, same three days. What we find in the ground doesn't change the invoice.

    From$620

    Residential site classification

    Two holes to 3.0 m on one lot, logged to AS 1726, classified to AS 2870-2011. The report your slab designer and your certifier both want, with the log sheet attached.

    Each$410

    Additional lot on the same visit

    The rig is already there and the crew is already paid to be on site. Eleven lots in a street costs a lot less than eleven separate call-outs.

    Add+$120 / $240Per lot

    Deeper holes — 4.5 m or 6.0 m

    Two storeys, a deep-fill platform, a raft or a screw-pile design. Deeper holes price the rig time and the footing design; they don't change your class.

    Add$240Per lot

    Fill-depth investigation

    Extra holes and sampling to prove how deep the fill actually goes. Compulsory on a P site — a P classification has to show the fill's base, not guess at it.

    Flat$180

    Outer-metro travel

    Mandurah, Two Rocks, Mundaring and the blocks in between. One flat charge for the visit, however many lots we do while we're down there.

    At costQuoted

    Regional WA

    Wheatbelt, South West, Goldfields. Travel is quoted on the run once we know where and when — we pass it through at cost and we say the number before the rig leaves the yard.

    Demo reviews

    What people say once the log lands

    ★★★★★

    I'm an owner-builder and "you need a soil test" was the sentence that stopped me for a fortnight. Datum booked me in on the Tuesday, bored Thursday, and the Class A report was with my slab designer the following Monday. Somebody actually explained what the letter meant.

    Nathan R. · Baldivis · Class A, two holes to 3.0 m

    ★★★★★

    Our 1930s block had 1.6 m of old fill across the back half and nobody had mentioned it — not the agent, not the first builder. The log showed exactly where it stopped. It cost us a redesign, but it cost us the redesign before the concrete, not after.

    Helen and Sam D. · Mount Lawley · Class P, fill-depth investigation

    ★★★★★

    Eleven lots, one morning, one invoice. I've had testers turn up on eleven separate days and bill me eleven mobilisations for the same street. These blokes priced it as one visit up front and the reports came back numbered to match my lot plan.

    Costa V. · builder, Wanneroo · 11 lots, one visit

    Out of the Malaga yard

    Two Rocks to Mandurah, and up the scarp as far as the truck will go

    Service area from the Malaga yard A simplified plan of the Perth metropolitan area between Two Rocks in the north and Mandurah in the south, with the Darling Scarp drawn as a banded ridge along the eastern edge. The Malaga yard is marked, with Wanneroo, Mount Lawley, Roleystone, Baldivis, Mundaring and Mandurah labelled. The metro band carries no travel charge; Mandurah, Two Rocks and Mundaring sit in the outer-metro band at one hundred and eighty dollars for the visit. Indian Ocean DARLING SCARP Malaga yard Wanneroo Mount Lawley Roleystone Baldivis Mundaring Mandurah Two Rocks
    Perth metro — no travel charge Malaga yard Darling Scarp — laterite country Swan River

    Two Rocks, Mundaring and Mandurah sit outside the metro band — outer-metro travel is $180 for the visit, however many lots we do while we are down there. Regional WA is quoted on the run and passed through at cost.

    Book the rig

    Tell us where the block is and we'll get a rig on it

    Set the job on the Log first and it fills this in for you — the profile, the depth, the lots, the investigation and the zone all land in the site details.

    We'd call you back the same working day with a bore date, the access we need for the truck and what your builder will want in the report. This is a demonstration page — nothing is sent anywhere.

    Who should we ask for — letters, spaces, apostrophes and hyphens.

    A number we can ring back — digits, spaces and + only.

    Pick the closest — it sets the travel.

    One is fine. Tell us if it's a whole street.

    It tells us how fast you need the report.

    Optional — tells us which week to aim for.

    A line or two is plenty.

    We need a tick here before we'd ring you.

    Or call (08) 9000 0391

    Asked on the block

    The six questions we get before every job

    What is a site classification, and why does the slab designer want one?
    A site classification is a letter — A, S, M, H1, H2, E or P — that tells your engineer how much the ground under your slab is going to move as it wets up and dries out through the year. We bore holes, log what comes up, sample the reactive layers and work out the characteristic surface movement, written ys and given in millimetres. AS 2870-2011 turns that movement into the class, and the class sets the minimum footing system the designer starts from. Without it your designer either can't start or has to assume the worst, and assuming the worst costs you concrete you may not need.
    How many holes, and how deep do they go?
    Two holes on a standard residential lot, taken to 3.0 m, is our normal scope and it is what the $620 covers. Perth's design suction change depth is 1.8 m, so 3.0 m gets us comfortably past the layer that does the moving on most metro blocks. We go to 4.5 m or 6.0 m when there's a second storey, a deep-fill platform, a raft or a screw-pile design in the mix, or when the first hole tells us the interesting stuff hasn't finished yet. On a bigger or oddly shaped lot we'll say up front if we want a third hole.
    What do the classes actually mean in plain words?
    A is sand that barely moves — most of the coastal plain, and the cheapest slab you'll ever pour. S is slightly reactive, a bit of clay in the profile, up to 20 mm of movement. M is moderately reactive, 20 to 40 mm — a lot of the Guildford formation through the eastern suburbs sits here. H1 and H2 are highly reactive, E is extreme, and each step up means a stiffer footing. P is different: it isn't a movement number at all, it's "problem site" — uncontrolled fill, soft or collapsing soils, or ground that has to be dealt with on its own terms before anybody designs a footing.
    How long does the report take?
    Three working days from the bore, straight to your builder or designer, with the log sheet, the strata descriptions, the water table if we struck it, the sample results and the classification with its reasoning. If the block is holding up a slab booking, tell us on the phone — we've turned reports around next day plenty of times and we won't charge you extra to do it, we'll just tell you honestly whether we can.
    What happens if you hit fill, or rock, or water?
    All three happen and none of them changes the fee. If we hit rock we log the refusal depth and say so. If we strike groundwater we record the level and the date, because a water table read in August isn't the same as one read in February and your designer needs to know which it is. If we hit uncontrolled fill it becomes a P site, and P sites need the fill's depth proven rather than guessed — that's extra holes and extra sampling, which is the one thing on this page the ground itself does add to your invoice. We show it to you as a locked line before you commit, not afterwards.
    What don't you do?
    We log and classify. We don't design your footings — that's your structural engineer's job, and we'd be marking our own homework if we did both. We don't do contamination assessments, acid sulfate soils or asbestos-in-soil clearance; those are a different scope with a different scientist attached, and we'll tell you who to ring. We don't do CBR pavement testing for driveways or car parks. And we don't tell you a block is fine over the phone before we've bored it — anybody who does is guessing.
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