Rock Breaking Services WA 2026 - Get Quotes

What Rock Breaking Actually Involves

Rock breaking is what happens when an excavation stops being an excavation. A bucket moves sand and clay at a predictable rate, and when it reaches material it cannot cut, the job switches to a different tool, a different rate and a different timeframe. The most common arrangement on a domestic site is a hydraulic hammer fitted to the excavator in place of the bucket, working the rock into pieces small enough to lift out. Everything about the economics changes at that point, which is why it deserves its own line in a quote instead of being buried in an hourly rate. Nobody enjoys the conversation, and having it before the machine arrives is far better than having it afterwards.

Every contractor quoting your job should be able to say how they intend to handle rock if it turns up. The hammer itself is a percussion tool driven by the machine's hydraulics, with Epiroc, Rammer, Indeco and Montabert among the units commonly fitted here. It delivers rapid blows through a steel point, fracturing the rock along its natural weaknesses instead of cutting through it, and the operator works methodically across a face rather than attacking one spot. Progress is measured in hours and cubic metres, not in bucket loads. An experienced operator reading the rock will make far faster progress than an inexperienced one hammering in the wrong place. Points wear and need replacing periodically, which is part of what the hourly rate covers.

Hammering the same spot for twenty minutes without progress usually means the operator should be working a different face. An operator who stops to reposition is reading the rock instead of fighting it. Machine size and hammer size have to match both the rock and the access. A three tonne Kubota or Yanmar with a small hammer will work all day on material a thirteen tonne Caterpillar, Komatsu or Hitachi machine would clear in an hour, and on a narrow Perth infill block the thirteen tonne machine may simply not fit down the side.

That trade off between capability and access decides a great deal of the cost. The excavation and earthmoving page covers machine selection across the full range of earthworks. Establish which machine will actually turn up, since the one quoted and the one available are not always the same. Access width down the side of the house is worth measuring before anyone quotes. What comes out of the ground has to go somewhere and limestone is heavy. Broken rock bulks up considerably from its in ground volume, so a hole that looked modest produces a surprising number of truckloads, and cartage is charged per load, not per hour.

On sites with room, crushing the material and reusing it as fill or base saves both the cartage out and the fill coming back in. That decision is worth raising before the work starts, not once the pile exists. A cubic metre of limestone in the ground can become a third more again once broken. A single cartage figure tells you nothing without an expected number of loads beside it. Settle where the material is going before the first truck leaves.

Timeframes are the thing owners underestimate most. A footing trench that would take an afternoon in sand can take two days through caprock, and a pool dig that struck limestone at a metre can add a week to a builder's program. Nothing about hammering is fast, and pushing an operator to hurry produces broken points and damaged machines instead of progress. Building that possibility into the schedule from the start removes most of the stress.

Push for a realistic day count, because the optimistic one is always wrong. The work is also noisy, dusty and unpleasant for everyone nearby, and that has practical consequences on a suburban block. Neighbours notice a rock hammer in a way they never notice a bucket, and a job that runs for days on a quiet street generates complaints unless people have been told. Warning the neighbours in advance costs nothing and buys a great deal of patience. It is the single cheapest thing you can do to make a rock job run smoothly. A note in the letterbox naming the days and a contact number does most of the work.

Western Australian Ground Conditions

The Perth coastal plain is where most domestic rock work happens and Tamala limestone is the reason. It forms the Spearwood dune system running the length of the metropolitan coast, and it turns up under the sand through suburbs from Yanchep and Joondalup in the north, through Scarborough, Karrinyup, Cottesloe and Fremantle, and south through Rockingham towards Mandurah. Depth to rock varies enormously over short distances, so one house on a street can dig four metres of clean sand while its neighbour hits caprock at six hundred millimetres. That variability is exactly why nobody should promise you a rock free dig without testing. Older suburbs closer to the coast tend to sit on the shallower end of that range.

A street where several houses have limestone garden walls is usually telling you something. The limestone itself is not one material and its behaviour varies. In places it is a soft, crumbly, sandy limestone that a machine can rip through with tynes at reasonable speed, and elsewhere it is a hard caprock layer that needs sustained hammer work. There are also nodular and cemented bands within the profile, so a dig can pass through easy material into hard material and back again. An operator will tell you within an hour of starting which kind you have. Once the operator is into it, their read on what they are seeing shapes the rest of the day.

The eastern suburbs sit on a different soil altogether and generally see less rock. The Bassendean sand system through the eastern corridor is deep, grey and largely free of limestone, which is why excavation through those suburbs is usually straightforward and why the contrast with coastal quotes can be stark. Coffee rock, a cemented iron rich layer, does appear in places and can be hard enough to need a hammer. It is far less common than the coastal caprock.

Owners in those suburbs are often surprised how much cheaper their dig is than a coastal equivalent. It is worth knowing which side of that line your suburb falls on before you start comparing quotes. The hills bring a completely different problem. Through the Darling Scarp, from Kalamunda and Mundaring down to Roleystone and Armadale, the ground contains granite and lateritic ironstone, often as floaters sitting within clay and often as solid bedrock closer to the surface. Granite is considerably harder than limestone and slower to break, and a hills excavation can encounter a boulder the size of a car that has to be broken in place because nothing on site can lift it.

The sloping block and Perth Hills retaining walls page covers the related retaining work on those sites. Floaters are particularly awkward because nothing about the surface predicts them. Regional Western Australia is varied and generally harder than Perth. The Wheatbelt and Goldfields have granite at or near the surface across large areas, the South West has laterite and granite through the Darling Range extension, and the Mid West and Pilbara have their own hard rock profiles. Local contractors in those areas work with it constantly and price accordingly. Bringing a metropolitan contractor to a regional rock job without local knowledge rarely ends well.

Freight on plant and the distance to a tip both weigh more heavily outside the metropolitan area. A local operator will also know which paddocks and streets have given trouble before. Groundwater adds a complication in parts of the coastal plain. In low lying suburbs the water table sits close to the surface, particularly through winter, and a dig that reaches both rock and water at the same depth needs dewatering alongside the hammer work.

That combination is common around wetland margins and in older suburbs near the river. It is another reason the site visit matters more here than the phone conversation. Pumping while hammering slows everything down and adds a separate line to the quote. Contractors who work those pockets carry the gear as a matter of course.

Finding the Rock Before You Dig

Test holes are the cheapest insurance available on any Western Australian excavation. A contractor brings a small machine or a hand auger, digs two or three holes in the footprint of the proposed work, and establishes at what depth rock appears and how hard it is. It takes a couple of hours, it costs a few hundred dollars, and it converts the largest unknown in the job into a number. On a pool dig or a house pad it is close to essential.

Two holes tell you far more than one, since depth to rock varies across a single block. Have the holes photographed and the depths recorded in writing. Geotechnical reports go further and they are required on many building jobs anyway. A soil classification report for a new dwelling identifies the profile, the bearing capacity and the presence of rock, and where one exists for your block it should be handed to the excavation contractor at quoting stage. Builders commission these routinely, and owners often have one sitting in a folder without realising what it tells them. Get a copy from your builder before you go looking for excavation quotes.

A report commissioned for the house build is equally valid for the pool or the shed that follows. Neighbours are an underrated source of information. Somebody on your street has put in a pool, a soakwell system or a shed slab in the last few years, and they will remember exactly whether the machine hit rock and roughly how much it added. Two conversations over the fence can be more useful than an hour of speculation. It also tells you which contractors worked in the street and how that went.

What the job ended up costing against what it was quoted at is the genuinely useful number. Existing evidence on the property is worth reading. Limestone outcropping in a garden bed, a retaining wall built from rock quarried on site, an old soakwell that was clearly hand dug into rock, or a neighbour's cut and fill exposing a rock face all point to what is underneath. Older Perth properties frequently have limestone walls built from material dug out of the block itself.

None of it is conclusive and all of it is a signal. A rock face exposed in a neighbouring cut is the most direct evidence available. Service location is a separate exercise and it is not optional. Before any excavation, the free national referral service reached on 1100 provides plans showing registered underground assets, and those plans need to be on site before a machine starts. Hammering into an unmarked service is considerably worse than hammering into rock. The plans are indicative and not precise, so potholing by hand to confirm the position of anything close to the dig is standard practice.

Plans are provided free, and the referral service covers registered networks only, not private lines. Private services such as a bore line or an old irrigation main will not appear on them at all. What all of this produces is a quote you can rely on. A contractor who has seen test hole results can price the hammer time with reasonable confidence, and a contractor working blind has to either pad the number or leave it open.

Paying for the testing usually costs less than the padding. The building inspection page covers arranging a broader property assessment where the excavation forms part of a larger project. It also gives you a document to point at if the ground later disagrees with the assumption. On a block where the neighbours have all struck rock, that document is worth having before anybody signs.

Hammers, Saws and Expansive Grout

The hydraulic hammer is the default and it handles most of what Western Australia presents. Fitted in place of the bucket, it is sized to the machine, and the operator works the rock progressively instead of trying to shatter it in one place. For bulk excavation, pool digs, house pads and broad footings it is almost always the tool used. It is also the noisiest option, which matters on a suburban street.

The hammer needs to be sized to the machine, because an undersized pairing works slowly and wears out quickly. Ripping with tynes is faster and cheaper where the material allows it. A ripper tyne fitted to the excavator or a Caterpillar or Komatsu dozer tears through weathered, soft or fractured rock without the hammering, and in softer Tamala limestone it can move material at several times the rate. It is useless against solid caprock or granite. A good operator tries ripping first and switches to the hammer when the ground says so.

An operator who tries the tynes first is saving you money, not wasting time. Rock saws and wheel trenchers suit narrow trenches and produce a far better result than a hammer does. Where a service trench has to run through limestone, a saw cuts a clean sided trench to a consistent depth without the overbreak a hammer creates, which means less backfill and less reinstatement. The plant is specialised and not every contractor has it, so availability can dictate the program. The trenching page covers service trenching in detail. Backfilling a hammer trench takes more material and more compaction than backfilling a sawn one.

Whether the contractor owns the saw or hires it determines how quickly they can get to you. Expansive grout is the quiet option and it has a genuine place. A non explosive chemical agent is poured into drilled holes, expands as it cures and splits the rock over a number of hours with almost no noise and very little vibration. It suits sites where noise limits are tight, where a neighbouring structure is close, or where access will not take a machine with a hammer. It is slow, weather sensitive and priced per hole, so it is a specialist answer and not a general one.

It is also the method most often used close to a heritage listed structure. Core drilling and saw cutting handle the precise work. The bulk goes elsewhere. Where a neat opening is needed through rock or an existing concrete structure, or where a clean edge is required at a boundary, drilling and sawing give a controlled result that a hammer cannot. The concrete cutting and coring page covers that work. On most domestic rock jobs it is a small component alongside the hammer work.

Diamond tooling is used for both, and the rate reflects the consumables as much as the labour. Blasting is essentially not a domestic option in metropolitan Perth. Explosives use is tightly regulated in Western Australia, requires licensed shot firers and approvals, and is confined to quarrying, mining and major civil work. Anyone offering to blast rock out of a suburban back garden should be treated with considerable scepticism.

Mechanical breaking is what your job will use. Anyone who raises it is telling you they do not work in this market. What comes out afterwards is a decision worth making deliberately. Broken limestone can be carted to a recycler or a tip at a per load cost, or crushed on site with a mobile crusher and reused as fill, driveway base or retaining wall backfill.

Crushing needs room, a day of plant hire and a use for the product, and where those exist it often beats paying to cart material out and buy base material back in. The skip bin hire page and the rubbish removal page cover the disposal side on smaller jobs. Crushed limestone makes serviceable driveway base and retaining wall backfill. Work out what the crushed product would be worth to you before deciding to cart it away.

Where Rock Breaking Comes Up

Pool excavation is the job that most often turns into a rock job in Perth. A pool shell needs a hole of a defined depth and shape, the depth commonly reaches the limestone profile in coastal suburbs, and there is no option to make the hole shallower. Pool builders generally exclude rock from their contract price and charge it as a variation, which is why so many pool projects run over. The pool excavation page covers the dig in detail and the swimming pool construction page covers the wider project.

A rock variation arriving mid build is one of the more common causes of a pool project running over. Soakwells are the second most common. Perth disposes of stormwater on the property and not into the street, so every house needs storage in the ground, and the wells have to go deep enough to hold the required volume. Striking limestone partway down means either hammering deeper or fitting more wells at a shallower depth, and the second is often the cheaper answer. The soakwell installation page covers sizing and placement, and the drainage page covers the wider system. Shallower wells across a wider area often cost less than hammering deep in one place.

Have the contractor price both arrangements so the comparison is visible. Footings and slabs bring rock into the builder's program. A footing trench has to reach the founding depth the engineer specified, and if that depth is in rock then hammer work is the only route there. On the other hand, rock can be good news structurally, since founding on sound limestone gives excellent bearing. The concrete slab page covers the slab side and the underpinning services page covers remedial work on existing footings.

Founding on rock can also remove the need for deeper footings elsewhere on the build. Service trenches run into rock constantly and they are where a saw earns its money. Power, water, sewer, gas and telecommunications all need trenches at defined depths, and a run of thirty metres through caprock is slow work with a hammer. Where the alternative is trenching around the rock, it is often the route that changes and not the method. The plumbing services page and the electrical services page cover the trades whose work follows the trench. Moving a trench line two metres sideways sometimes avoids a week of hammering.

See whether the route can be changed before the hammer goes on. Retaining and level changes on rocky blocks are a Perth Hills specialty. Cutting into a slope to create a building platform or a flat garden area frequently means cutting into rock, and the exposed rock face then becomes part of the design instead of something to be hidden. Limestone in particular can be cut to a face and left.

The limestone retaining walls page covers the walls that usually follow the cut. A cut rock face also needs assessing for stability before anything is built against it. Driveways, sheds and outbuildings all need a prepared base at a set level, and on a rocky block reaching that level can mean breaking. A crossover at the verge has a level set by the council that cannot be negotiated, so if rock sits above it, the rock comes out. The driveway excavation page covers the base preparation stage in more detail.

Crossover levels are set by the council. They are not negotiated with the contractor. Landscaping generates a steady stream of smaller rock work. Tree planting holes, pool surrounds, garden bed excavation, water features and post holes for fencing and pergolas all stop dead at limestone, and the fix is often a small machine with a hammer for half a day.

The landscaping page and the post hole digging page cover that end of the work. It is the category owners least expect to need a hammer for. A half day machine hire with a hammer is a common and reasonable minimum charge. On a small garden job, that minimum is usually the whole cost.

Noise, Dust and Vibration

Construction noise in Western Australia is regulated and rock hammering sits at the loud end of it. The state's environmental noise regulations set out permitted hours for construction work and the limits that apply, with local governments handling complaints and enforcement, and work outside those hours generally requires approval. A rock hammer running at seven on a Sunday morning is a complaint waiting to happen. Contractors who work in built up areas know the hours and plan around them. Councils differ on permitted hours, so the answer is a local one, not a statewide rule. Work approved outside standard hours usually carries conditions about notification.

Telling the neighbours beforehand changes everything about how a noisy job is received. A note in the letterbox or a knock on the door a few days ahead, saying what is happening, roughly how long it will run and who to call, converts a nuisance into an inconvenience. People tolerate a great deal when they have been treated as adults about it. It costs a contractor ten minutes and it saves everybody a difficult week.

Being the owner who warned the street is also considerably more comfortable than being the one who did not. Silica dust is the health issue that matters most and it is not obvious to a homeowner watching from the kitchen window. Breaking rock generates respirable crystalline silica, which causes serious and irreversible lung disease with long term exposure, and the controls are water suppression at the tool, enclosed cabs with filtration and respiratory protection where needed. Workplace exposure to it is regulated in this state by WorkSafe WA. A crew hammering dry with no water and no masks is not managing it. Wet cutting and wet hammering are standard practice, not optional extras.

Dust is also a neighbour issue on a still Perth day. Fine limestone dust travels, settles on cars, pools and washing, and gets into houses through open windows. Water suppression handles most of it and a contractor who mentions dust control before you do is thinking about the whole job. Asking neighbours to close windows and bring washing in on the worst days is a reasonable courtesy. A light water spray on the working face keeps most of it on the ground.

Vibration is the risk to buildings. The risk to people is a different one. A hammer working close to a boundary transmits energy through the ground, and on older masonry, a limestone wall, a pool shell or a structure already showing movement, that energy can open cracks. Where the work sits close to something sensitive, a photographic condition survey of the neighbouring structure before work starts protects both sides.

It takes twenty minutes and it settles an argument that would otherwise be unwinnable. Photographs with a date on them are all that is needed. A short walk around the neighbouring property with the owner present is better still. Access damage is the other thing to document.

Getting a machine and a hammer into a back garden usually means crossing the verge, the crossover, paving and lawn, and heavy plant marks all of them. Photographs of the access route before the machine arrives, and an agreement about reinstatement in the quote, prevent most disputes. The paving and driveway installation page covers repairing paving damaged during access. Agreeing who reinstates what, and to what standard, belongs in the quote and not in a later conversation.

Provisional Rates and Variations

The honest way to quote rock is as a provisional item and every experienced Western Australian contractor knows it. The quote states the assumed ground condition, prices the excavation on that assumption, then nominates an hourly rate for hammer work if rock is encountered beyond the assumption. That way the base price is real and the variation is predictable. A contractor who refuses to nominate the rate in advance is keeping the number for later. It also lets you compare quotes on the same basis instead of on differing assumptions. The assumption itself needs to be written down.

Excavation to two metres in sand with no rock anticipated is a statement you can hold someone to, and a quote that simply says excavate to two metres is not. If the contractor has dug test holes, the assumption should reference what they found. This single line prevents most excavation disputes in this state. A single sentence naming the depth and the expected material is enough.

Hammer time should be recorded and agreed as it happens, because reconciling it at the end never goes well. Machines have hour meters, the operator knows when the hammer went on and came off, and a daily note signed or texted keeps everyone honest. An invoice arriving three weeks later with twenty two hours of hammer on it and no record behind it is difficult to check and difficult to challenge. Agree the recording method before the work starts. A photograph of the hour meter at the start and end of the day settles it entirely.

Most operators are happy to do this and it protects them as much as you. The hourly rate needs unpacking before you compare it with anything. It should cover the machine, the hammer attachment and the operator, and the quote should say whether cartage of the broken material is inside the rate or billed separately by the load. A rate that looks sharp until the truck invoices arrive separately is not a sharp rate. Asking the question in writing takes one line. Tip fees vary considerably between facilities, which is why the load figure matters.

Understand what happens if the rock is worse than assumed. Some contractors will stop and reprice, some will continue at the provisional rate regardless of volume, and some will want a conversation at an agreed trigger point such as a number of hours or a dollar figure. Any of those is fine provided it is agreed beforehand. Nominating a trigger where you are consulted before the cost passes a set figure gives you control without stopping the job. Set the trigger at a figure you would want to be consulted about, not at the total budget.

Set it in writing at the same time as the rate itself. Written variations are worth insisting on even when things are moving fast. A short email confirming what was found, what is proposed, the rate and the expected hours is enough, and it protects the contractor as much as the owner. Verbal agreements made over the noise of a machine are remembered differently by each side a fortnight later. Consumer guarantees under the Australian Consumer Law, administered by the ACCC, apply to this work as to any trade service. An email sent the same evening is enough to record it properly.

Where the excavation forms part of a building contract, the rock provision sits inside that contract instead. Builders commonly exclude rock from the contract sum and treat it as a provisional or excluded item, which means the owner carries it. Reading the exclusions in a building contract before signing is where that discovery should happen. The concrete demolition and site preparation page covers the wider site works stage on a build. Find out specifically whether rock is excluded from the contract sum and at what rate it would be charged. Builders will usually answer that question directly if it is asked before the contract is signed.

Costs in Detail

Rock hammering with an excavator runs $180 to $320 an hour across the Perth metropolitan area, covering the machine, the hammer attachment and the operator. The range reflects machine size, since a three tonne machine with a small hammer sits at the bottom and a thirteen to twenty tonne machine with a heavy hammer sits at the top. The larger machine costs more per hour and frequently costs less per cubic metre, which is why access matters so much to the total. Get the machine named on the quote, along with the reason for it. Establish which of the two is being quoted before comparing hourly figures. A provisional rock rate written into a quote commonly sits at $200 to $350 an hour, slightly above the straight hourly rate because it covers the disruption and the attachment change.

That is a normal and reasonable structure, not a penalty. What matters is that the number is in the quote before the work starts. A provisional rate agreed in advance is the difference between a variation and an argument. It also means every quote is built on the same structure. The assumption and the rate belong on the same page of the quote.

Test holes to establish depth and hardness run $350 to $900 depending on how many are needed and whether a machine or a hand auger is used. Against a pool dig or a house pad this is trivially cheap and it removes the largest unknown in the job. On a small soakwell job it may not be worth it. The decision scales with what you are about to spend.

Where the numbers are marginal, the testing at least tells you what the risk looks like. Pool digs that strike rock commonly add $1,600 to $3,200 a day while the hammer is working, and a bad Perth pool dig can add several days. Pool builders generally exclude rock, so this lands on the owner as a variation regardless of who does the work. Asking the pool builder what their rock provision is, before signing, is one of the more valuable questions in the whole project. Getting a test hole done before signing is better still. Getting that answer in writing before signing the pool contract is the whole point.

A pool contract that is silent on rock is the one to query hardest. Trenching through limestone runs $90 to $260 a linear metre depending on depth, width and hardness, and a rock saw on a longer run is quoted hourly at $220 to $400. The saw usually beats the hammer on cost per metre once the run is long enough to justify mobilising the plant. For a short run it rarely does. Have the contractor compare the two for your length.

A saw also leaves a trench that needs less bedding sand to make good. Disposal and reuse are the last variable and they can swing the total. Carting broken limestone away runs $180 to $420 a load depending on distance and tip fees, and crushing on site runs $1,800 to $4,500 a day for the mobile plant. Regional Western Australia prices differently again, with local contractors in Bunbury, Albany, Geraldton and Kalgoorlie working at comparable rates within their own areas and metropolitan crews adding mobilisation.

In the harder rock country of the Wheatbelt and Goldfields, expect both slower progress and fewer contractors to choose from. Crushed product either gets used on your site or sits in a stockpile, and those are different outcomes. Stockpiled material you never use is simply cartage you have deferred. Decide at the quoting stage whether there is a genuine use for it on the property.

What to Look Out For

Be very cautious of an excavation quote with no rock line at all on a coastal Perth property. Nobody can know what is under your sand without testing, and a quote that ignores the question has deferred it, not answered it. Get the assumed ground condition stated, along with what happens if rock appears. The answer tells you whether you are dealing with someone who has worked this ground before. It also tells you whether the contractor has genuinely worked this ground before.

Watch for an hourly rate with no cap, no trigger and no recording method. Open ended hammer time on a suburban block is an uncomfortable position to be in once the machine is already there. Agree how hours will be recorded, and nominate a figure at which you want to be consulted before the work continues. Neither request is unreasonable and a professional contractor will offer both. Both requests are ordinary practice on commercial sites and there is no reason a domestic job should differ. Look at the water supply arrangement on site instead of taking it on trust.

Check whether cartage sits inside or outside the quoted rate. Broken rock bulks up considerably and the loads add up quickly, and a rate that looks competitive can be beaten comfortably by one that includes disposal. Get the per load figure and the expected number of loads together. That conversation takes two minutes and it is where a great deal of money sits. Cartage rates usually assume a particular disposal facility, so find out which one.

Take the dust question seriously instead of treating it as a nuisance. Breaking rock produces respirable silica and the controls are water at the tool and proper respiratory protection for the crew. A team hammering dry with no water and no masks is not managing a known health risk, and that attitude to safety rarely stops at the dust. It is a fair thing to ask about before you engage them. Water at the tool is visible from the ground, so it is easy to check on the day. A crew working dry on a still day is visible from the street.

Be careful about vibration where a neighbouring structure is close. An older masonry wall, a pool shell, a limestone retaining wall or a building already showing cracks can all be affected by sustained hammering nearby. A photographic condition survey before work starts protects you and the contractor equally. Skipping it is how a neighbour's pre existing crack becomes your problem.

A neighbour who was consulted beforehand is far less likely to raise it afterwards. One last thing, be sceptical of anyone offering to blast. Explosives in Western Australia are tightly regulated, require licensed personnel and approvals, and have no place on a suburban domestic excavation. Mechanical breaking is what your job will use, and anyone suggesting otherwise is either not serious or not licensed.

Neither is what you want operating on your property. Mechanical breaking handles everything a domestic site will present. Anyone claiming otherwise has misunderstood the regulatory position entirely. Hammers, rock saws and chemical splitting between them cover every situation a Perth block produces.

How to Get Comparable Quotes

Gather what you know about the ground before you make contact. Your suburb and street, the depth you need to reach, the footprint of the excavation, whether any test holes or a geotechnical report exist, what neighbours have found, and anything visible on the property such as outcropping rock or limestone walls. Photographs of the site and the access route are worth including. Contractors quoting with that information price the actual job instead of an average one.

A short video of the site walking the access route is even more useful than photographs. Put the same questions to every contractor. The assumed ground condition, whether they will dig test holes and at what cost, the machine and hammer size proposed, the hourly rate for hammer work, whether cartage is included or billed by the load, how hours will be recorded, the trigger point for consulting you, dust and noise controls, access protection and reinstatement, and their insurance position. Written answers turn three prices into a genuine comparison. Every contractor should state what is excluded as plainly as what is included. Pay for test holes before you compare quotes on a large job.

Once every contractor is pricing against the same known conditions, the numbers become directly comparable and the padding disappears. On a pool dig or a house pad the testing cost is recovered several times over in the quality of the quotes. On a small job it is usually not worth it, and saying so honestly is part of the advice a good contractor gives. It also removes the temptation for a contractor to price the unknown generously. Bundle the rock work with whatever else needs a machine.

A hammer and an excavator on site for a pool dig can also break out an old slab, dig soakwells, form a shed pad and trench a service run in the same mobilisation, and the marginal cost of each is far lower than a separate visit. The excavation page covers the range of work that can be combined. Sequencing it into one visit is the single biggest saving available. See whether any of it can be done in the same visit as the main excavation.

Time the work sensibly where you have a choice. Winter excavation on the coastal plain can mean working in water as well as rock, and the wettest months make access and spoil handling harder on any site. Late summer and autumn give drier ground and easier conditions for both. Where a builder's program sets the timing, that flexibility does not exist, and knowing the constraint helps you price the risk properly. Where the program allows a choice, ask the contractor which months they would prefer.