Concrete Repair Costs WA 2026 - Get Quotes

What Concrete Repairs Cost in WA

Routing out a dormant crack, cleaning it and filling it with a flexible compound runs $15 to $40 a lineal metre, which makes it the cheapest genuine repair available. Injection with epoxy or polyurethane sits at $60 to $180 a lineal metre because it involves drilling ports, injecting under pressure and working the length of the crack methodically. Spalling and edge repair is priced by area at $120 to $400 a square metre, with the range reflecting how much sound concrete has to be cut back before the patch can begin. The visible damage is almost never the full extent.

Cutting out and replacing a failed section costs $180 to $350 a square metre, which is more per square metre than pouring a new slab because the demolition, the edge preparation, the small pour and the finishing all carry disproportionate labour. Small patch jobs are inefficient by nature. A day rate spread over two square metres always looks expensive. That is why a contractor will sometimes suggest replacing a whole panel rather than a two square metre patch, and on a jointed slab that advice is usually sound. It also produces a far better looking result.

Slab levelling by injection sits in its own category at $1,500 to $6,000 for a typical residential job. Structural grout or expanding polyurethane resin is injected beneath a settled slab through small holes to lift it back toward level, and the price depends on the void volume and the area rather than on the crack length. It is a specialist service and not every concreter offers it. Ask specifically rather than assuming a general concreter can price it.

Assessment is worth budgeting separately at $400 to $1,500 where the cause is not obvious. A structural engineer's inspection and report on a cracked slab or a moving driveway costs a fraction of a wrong repair, and it converts guesswork into a specification. Broader trade rates for new work sit at concreting costs. Compare against those figures when weighing repair against replacement.

How to Read a Crack

Almost every decision on this page follows from one question, which is whether the crack is still moving. A crack that formed as the concrete cured and has been stable ever since is a cosmetic problem with a cheap, permanent fix. A crack that opens and closes with the seasons, or that is being driven by ground movement, will defeat any filler you put in it. Telling them apart is the whole job. Everything after that decision is comparatively mechanical. The diagnosis is where the money is either saved or wasted.

The straight edge test costs nothing and takes thirty seconds. Lay a straight edge or a spirit level across the crack and check whether both sides sit in the same plane. A crack where the two faces remain level is almost always shrinkage. A crack with a vertical step between the sides means the ground under one side has moved. Run your hand across it if you have nothing else. A step you can catch a fingernail on is significant. Anything you can catch a shoe on is also a trip hazard and worth acting on sooner.

Width and pattern tell you more. Fine map cracking across a surface is crazing in the top layer and is cosmetic. A single crack running between two internal corners is classic shrinkage seeking the weakest line. A crack that widens toward one end, or runs diagonally across a corner, suggests one part of the ground is moving more than another. Cracks that follow the line of a buried service or a fill zone are telling you where the ground is soft. Trench lines across a driveway are a classic example. So is a crack that runs straight toward a pool or a footing.

Take dated photographs with a ruler or a coin in frame. Six photographs across six months turns an argument into evidence, shows whether the crack is opening or stable, and gives any engineer or contractor something concrete to work from. It is the single most useful thing a homeowner can do before spending money on this problem. It costs nothing but a few minutes a month.

Shrinkage Cracking

Concrete shrinks as it cures and it will crack somewhere, which is why control joints exist. Where jointing was inadequate, spaced too far apart or cut too late, the slab finds its own line and cracks between the points of greatest restraint, typically at an internal corner where the slab changes shape, along the edge of a pier, or between two openings. These cracks appear early in the life of the slab and then stop. If a crack has not changed in three years, it has almost certainly finished moving. That is the point at which a permanent repair makes sense.

Plastic shrinkage cracking is a related but earlier problem and it is specifically a Perth summer issue. On a hot day with a strong easterly, water evaporates from the surface faster than the concrete can bleed it, and shallow cracks open within hours of placement before the concrete has developed strength. They are usually short, roughly parallel and confined to the surface rather than running through the slab. They also indicate the pour was not protected properly, which is worth knowing if the slab is new.

The good news is that shrinkage cracks are stable and permanently repairable. Once the slab has cured and the crack has stopped moving, routing it out and filling with a suitable compound seals it against water and reinstates the surface, and it stays fixed. Most cracks people worry about on a two or three year old slab fall into this category. That is a genuinely reassuring statistic on this problem.

Crazing is different again and needs no repair at all. Fine map cracking in the top layer is cosmetic, extremely common on trowelled surfaces, and generally becomes less noticeable once the surface has weathered and been sealed. A contractor proposing an expensive treatment for crazing is solving a problem you do not have. Sealing the surface reduces its visibility if it bothers you. Otherwise it is safe to ignore entirely.

Movement and Settlement

A crack with a step in it, one that opens seasonally, or one that has clearly grown since you first noticed it is being driven by the ground rather than by the concrete. On the Swan Coastal Plain the usual culprits are uncompacted fill, backfill against a pool or a footing, a poorly compacted service trench crossing the slab, or erosion from water running where it should not. Sand is stable when compacted and unforgiving when it is not. Poorly compacted fill explains most settlement cracking in Perth. Fill placed in a hurry is the single most common origin.

Perth Hills and eastern suburbs sites bring reactive clay into the picture and the behaviour is different. Clay expands when wet and shrinks when dry, so slabs on those soils move seasonally, cracks open through summer and close through winter, and the movement is driven by soil moisture rather than by load. Site classification under AS 2870 exists precisely to size slabs for that behaviour, published through standards.org.au. A slab designed for sand and built on clay will move. So will one poured over a mix of both.

Filling a moving crack is not useless but it is temporary, and it should be sold to you as such. A flexible sealant will keep water out for a period even where movement continues, which protects the reinforcement and stops the crack widening through erosion, but it is maintenance rather than a cure. Anyone presenting it as a permanent fix on a stepped crack is either inexperienced or not being straight with you. Ask them directly what they expect it to achieve and for how long. An honest answer of two to three years is more useful than a vague promise.

The durable answer addresses the ground. Correcting drainage, stabilising or re-supporting the soil, underpinning where footings are involved, or removing what is causing the movement all attack the cause rather than the symptom. Where footing movement is implicated, that is a specialist trade covered at underpinning services.

Monitoring Before Repairing

Patience is genuinely cheaper than repair on this problem. Where a crack has appeared recently and the cause is unclear, monitoring it across a season costs nothing and tells you what you are dealing with, whereas repairing immediately risks paying twice. Six months spanning at least one wet season and one dry spell is the useful window in Western Australia. That means monitoring from roughly autumn through to spring.

Simple methods work well. Mark the ends of the crack with a pencil line and date them, measure the width at a marked point with a feeler gauge or a crack card, and photograph it monthly with a ruler in frame, so that by the end you know whether it has grown, whether it moves seasonally, and by how much. Tell-tale gauges are available cheaply if you want a number rather than an impression. Fixing one across the crack gives a readable measurement over months.

Watch what happens around it as well as to it. Water pooling nearby after rain, a downpipe discharging onto the ground beside the slab, a tree growing closer than it looks, or a neighbouring excavation all provide the explanation that the crack alone does not. The cause is usually visible if you go looking during the first serious downpour of winter. Standing outside in the rain for ten minutes is the most productive diagnostic available.

The exception to patience is anything structural or unsafe. A crack in a footing, a wall, a suspended slab or a retaining structure, a trip hazard on a path, or a crack accompanied by doors and windows binding is not a monitoring situation and warrants advice promptly. Building inspection services are listed at building inspections.

Routing and Flexible Fill

This is the standard repair for a dormant crack and it is more involved than it sounds. The crack is cut out with a small saw or grinder to create a clean, uniformly wide channel, the dust and debris are vacuumed out rather than blown around, a bond breaker or backing rod is placed where appropriate, and the channel is filled with a flexible polyurethane or polymer modified compound rather than with rigid mortar.

The routing step is what makes it last, and skipping it is the most common shortcut. Smearing filler into an uncut crack gives the compound almost no surface to bond to and no depth to flex within, so it fails within a year and often falls out in pieces. If a quote does not mention cutting or routing, ask why. It is the difference between a repair and a smear.

Material choice matters more than most homeowners realise. Rigid cementitious fillers work on genuinely static cracks and fail on anything that moves at all, while flexible polyurethane compounds accommodate small movement and stay bonded, which is why they dominate on external slabs. Manufacturers including Sika, Bostik, Ardex and Crommelin produce products across both categories with published specifications. Ask which product will be used and look up the data sheet. Movement capability is stated on it in plain terms.

The finished repair will be visible and anyone claiming otherwise is overselling. The filled line reads as a line, the colour rarely matches exactly, and on a decorative surface it is more obvious again, which is why cutting the repair to a joint line or a pattern line looks better than leaving it wandering. On a plain grey slab most people stop noticing it within a few months. On a decorative surface they never quite do.

Epoxy and Polyurethane Injection

Injection is the repair for cracks that go through the slab rather than sitting in the surface, and the two products do quite different jobs. Epoxy is rigid and strong, so injecting it into a crack effectively welds the two sides back together and restores structural continuity, which suits a static structural crack in a wall, a beam or a suspended slab. It is not suitable where movement will continue, because a rigid bond simply cracks again beside the repair.

Polyurethane is flexible and expands on contact with water, which makes it the product for sealing cracks against water rather than for structural bonding. It suits basement walls, retaining structures, water tanks and any crack where the objective is to stop leakage and accommodate slight movement. Choosing between the two is a technical decision and a contractor should be able to explain why they have chosen one. A vague answer on that point is a reason to get another opinion.

The process is methodical. Injection ports are fixed along the crack at spacings related to the slab thickness, the surface between them is sealed so the material cannot escape, then resin is injected under pressure port by port until it appears at the next one, and the surface seal and ports are removed once cured. Done properly it fills the crack through the full depth. Done in a hurry it fills the first fifty millimetres and nothing else.

At $60 to $180 a lineal metre it is considerably more expensive than routing and filling, and it is the right answer far less often than it is proposed. On a domestic driveway or path, a through crack that is not moving rarely needs structural bonding, and a flexible surface repair achieves the practical objective for a fraction of the cost. Ask what the injection is achieving that a routed repair would not. It is a fair question and there is sometimes a good answer. Where the crack leaks water into a garage or a basement, injection earns its cost.

Spalling and Concrete Cancer

Spalling is concrete breaking away from the surface, and where it happens over embedded steel it usually has one cause. Reinforcement corrodes, the corrosion products occupy several times the volume of the original steel, and that expansion pushes the surrounding concrete off. Once you can see rust staining or exposed bar, the process is well advanced. Brown staining without visible cracking is the early warning. Acting at that point is far cheaper than waiting.

The repair follows a fixed sequence and shortcuts guarantee failure. All loose and unsound concrete is removed back to solid material, the exposed steel is cleaned back to bright metal and treated or replaced where section loss is significant, a bonding agent and where appropriate a corrosion inhibitor is applied, and a repair mortar is built up in layers and finished. Patching over rusted steel simply traps the problem and it returns within a couple of years. It is the most common failure in amateur spalling repair. It also hides the problem long enough for a property to change hands.

Cutting back further than the visible damage is normal and correct. The concrete immediately around a corroding bar is usually already compromised even though it looks sound, so a proper repair removes material well past the obvious edge, which is why a small visible defect can become a much larger patch. That is competence rather than upselling. A repair that stops at the visible edge will fail at the edge.

Where spalling is extensive on a structural element, it stops being a maintenance job. Balconies, suspended slabs, carport beams and anything overhead with significant section loss need engineering assessment before repair, since the capacity of the element may be compromised. Independent assessment is available at building inspections.

Coastal Exposure and Reinforcement

Western Australia's coastal strip is an aggressive environment for reinforced concrete and Perth is a coastal city for most of its length. Salt carried in the air soaks into the concrete over years, and once it reaches the reinforcement it strips away the chemical protection that normally keeps the steel from rusting, so corrosion starts earlier and moves faster than it would inland. Structures within a kilometre or two of the ocean carry meaningfully higher risk. Perth's western suburbs, the northern coastal corridor and Mandurah all sit in that band. So do Geraldton, Albany and the Pilbara ports.

Concrete cover over the steel is the primary defence and it is decided when the slab is poured. Adequate cover, a dense mix that water struggles to pass through, and proper compaction together slow that salt migration dramatically, while inadequate cover from mesh sitting too close to the surface produces spalling in a fraction of the expected life. Exposure classifications and durability requirements sit under AS 3600, and concrete supply under AS 1379. Those standards are why coastal specifications differ from inland ones.

This is why coastal spalling repairs often reveal a construction problem rather than an age problem. A twelve year old balcony in Scarborough or Cottesloe showing rust staining usually has cover measured in millimetres rather than the specified amount, and repairing the visible damage without addressing the underlying cover issue means the next patch is already scheduled. A cover meter survey answers the question quickly. It is inexpensive and it changes the repair strategy entirely.

Protective treatments buy time on structures at risk. Penetrating sealers, protective coatings and corrosion inhibitors applied before spalling begins extend service life at modest cost, which makes them worth considering on a coastal property while the concrete still looks sound. It is far cheaper than repair. Applying a sealer to a sound coastal balcony costs a fraction of remediating a spalled one. Sealing and surface treatment options sit at concrete resurfacing costs.

Joints and Sealant

A surprising share of what people describe as cracking is actually a failed joint. Control and isolation joints are meant to move, they are filled with a flexible sealant rather than a rigid material, and that sealant has a service life, so a perished or missing sealant lets water and grit into a joint that was working perfectly well. Cleaning and resealing runs $18 to $45 a lineal metre. It is the cheapest preventative maintenance available on concrete.

Joint sealant fails predictably under Western Australian conditions. Ultraviolet exposure, high surface temperatures, movement cycling and grit working into the joint all degrade it, and five to ten years is a realistic life on an external joint in full sun. Inspecting the joints every couple of years and resealing before they fail is cheap maintenance that prevents expensive problems. Put it on the same cycle as gutter cleaning.

Water entering a failed joint causes damage disproportionate to the cost of the sealant. It erodes the base beneath the slab edge, carries grit that jams the joint so it can no longer close, and where reinforcement runs near the joint it accelerates corrosion, all of which converts a maintenance item into a repair. Joints beside a pool or a wet area deserve particular attention. They are wet more often and degrade faster.

Isolation joints against buildings are the ones most often neglected. The joint between a slab and a house wall is doing important work in letting the two move independently, and where it has been filled with mortar, paved over or simply never formed, cracking at that line is the predictable result. Where water at that junction is affecting the building, see rising damp assessment and repairs.

Slab Levelling by Injection

Where a slab has settled but is otherwise sound, lifting it back toward level is often better value than replacing it. Small holes are drilled through the slab, expanding polyurethane resin or a cementitious grout is injected beneath it to fill voids and raise the slab, and the holes are patched. A typical residential job runs $1,500 to $6,000 depending on area and void volume.

It suits specific situations rather than being a general answer. A settled but intact driveway panel, a path that has dropped at a service trench, a garage floor with a void beneath it, or a slab sitting over poorly compacted fill are all good candidates, while a slab that has broken into pieces, has significant reinforcement corrosion or sits on ground that is still moving is not. The slab has to be strong enough to be lifted as a unit. A slab that flexes or breaks under the lift is not a candidate.

The advantages over replacement are speed and disruption. Injection is usually a single day, the surface is trafficable almost immediately, there is no demolition, no cartage and no new concrete to cure, and the existing finish is retained rather than replaced with something that will not match. On a driveway that would otherwise be out of action for a week, that matters. It also avoids the colour mismatch a replacement panel brings.

Ask what happens if the void refills. Injection fills the void that exists on the day, and where the cause of that void is ongoing, such as water eroding fill or a leaking service, the settlement will resume unless the cause is fixed. A contractor who asks about drainage before quoting a lift is thinking correctly. One who does not has priced a symptom. Drainage scope is priced at drainage.

Cutting Out and Replacing

Sometimes the honest answer is that a section has had its day. Where an area has broken into multiple pieces, where the reinforcement is badly corroded through, where the slab is too thin for what now uses it, or where movement has left displacement too large to repair, cutting out and replacing that section at $180 to $350 a square metre is the durable answer.

Cutting to a joint line is what makes a replacement look intentional. Saw cutting along an existing control joint or a pattern line means the new work meets the old at a line that was always there, whereas a rectangular patch cut in the middle of a panel will read as a patch for the life of the slab. On a jointed driveway, replacing whole panels is usually both neater and barely more expensive. The saw cutting is already happening either way.

The new section has to be tied in properly or the joint between old and new becomes the next crack. Dowels drilled and epoxied into the existing slab, or a properly formed keyed joint, transfer load across the junction and stop the two sections moving independently, and a new pour simply butted against an old one without connection will separate. Ask how the tie in will be done. The answer should mention dowels or a keyed joint rather than nothing.

Colour will not match and it is better to accept that up front. New concrete is lighter than weathered concrete and takes years to approach the same tone, so a replaced panel will be visible for a long time, and on a coloured or decorative surface it may never match at all. Where the whole area is tired, replacing more of it produces a better result. Half a driveway in two tones rarely satisfies anyone. Removal and disposal are priced at demolition services and skip bin hire.

Underlying Causes

Repairing without understanding the cause is how people end up paying twice. The common underlying causes in Western Australia are uncompacted or eroded fill beneath the slab, reactive clay movement on Hills and eastern suburbs sites, tree roots, water going somewhere it should not, inadequate slab thickness or reinforcement for the load, and inadequate cover over the steel in coastal exposure.

Original construction explains more failures than people expect. A slab poured too thin, with mesh lying on the sand rather than supported on chairs, over a base tipped rather than compacted, or without adequate jointing will crack regardless of what happens afterwards, and no repair changes those facts. Where a slab is only a few years old and already failing, the construction is the first place to look. That may also have implications for any warranty on the original work.

Loading changes are a quieter cause. A path built for foot traffic that now takes a trailer, a driveway designed for cars that now carries a caravan, or a slab that has a shed or a spa placed on it are all being asked to do something they were not designed for, and cracking is the predictable result. Slab design for a given load sits at concrete slab costs.

Adjacent work is worth considering where cracking appears suddenly. Excavation on a neighbouring property, a new pool nearby, service trenching across the frontage or a retaining wall built close by can all change how the ground behaves under an existing slab. Timing is the clue, and where the cracking began within months of nearby works, that is worth documenting. Photographs with dates carry weight in that conversation.

Tree Roots

Trees damage concrete in two distinct ways and the difference matters for the fix. Roots growing beneath a slab lift it directly, producing localised heave, a trip hazard and cracking radiating from the raised point, while on reactive clay a large tree draws moisture from the soil and causes shrinkage settlement in the opposite direction. Lifting and settlement can occur on the same property from the same tree. Which one you get depends on the soil rather than the species.

Root pruning is a specialist decision rather than a DIY one. Cutting major structural roots on one side of a mature tree can destabilise it and eventually kill it, which turns a concrete problem into a tree problem and a potential safety issue, so an arborist should assess before any roots are cut. Arborist services are listed at tree lopping and arborist services.

Root barriers are the preventative measure and they work best installed before damage occurs. A physical barrier set vertically in a trench between the tree and the slab redirects root growth downward rather than under the concrete, and installing one at the same time as a repair prevents the repair from being undone. Retrofitting is more disruptive but still worthwhile where the tree is staying. It is far cheaper than repeating a concrete repair every few years.

Where the tree is coming out, the stump and root system are part of the job. Leaving a large stump in place beneath a new slab means the void created as it decays will eventually cause settlement, which is why removal rather than grinding at surface level is preferable under anything being concreted. Stump work is priced at stump grinding and removal. Street trees on the verge are council assets and have their own rules. Removing or pruning one without approval carries penalties.

Water and Drainage

Water is behind more concrete failure in Western Australia than any other single factor, and it is usually the cheapest thing to fix. Free draining Perth sand carries water readily, which is helpful when it goes where it should and destructive when it does not, since water running repeatedly under a slab edge erodes the fill supporting it and produces the void that leads to settlement.

The usual sources are obvious once you look. A downpipe discharging onto the ground beside a slab, a soakwell that has silted up or was undersized, reticulation spraying against an edge, a leaking service, or ground that falls toward the house rather than away from it will each undermine a slab over a few seasons. Watch the property during the first serious downpour of winter and the answer is generally visible. Take photographs while it is happening, because it is not visible in January. Rain photographs are the most persuasive evidence you can bring to a contractor.

Fixing drainage is almost always cheaper than repeating a concrete repair. Extending a downpipe, adding or cleaning a soakwell, correcting a fall, or intercepting surface water with a grate costs hundreds where a settled slab costs thousands, and it is the step most often skipped in the rush to make the crack disappear. Soakwell capacity and sizing is covered at soakwell installation costs.

Western Australian local governments generally require stormwater to be disposed of on site rather than discharged to the street, so the drainage fix has to work within that framework rather than simply moving water somewhere else. Adding hardstand also adds catchment that an existing system may not have been sized for. A new patio or driveway can push an adequate soakwell past its duty. Wider stormwater scope sits at stormwater drainage plumbing.

When to Get an Engineer

Most driveway and path cracking does not need an engineer, and paying for one on a shrinkage crack is money wasted. Engineering advice earns its cost where the cracking involves a structural element, where movement is continuing, where the cause is genuinely unclear, or where the repair cost is large enough that getting it wrong hurts. Below that threshold it is an unnecessary expense.

The clear triggers are worth knowing. Cracking in footings, walls, beams, columns or suspended slabs, cracking accompanied by doors and windows binding or by visible distortion in the building, cracks wider than a few millimetres that are still growing, spalling with significant section loss in the steel, and any element carrying load overhead all warrant assessment before repair rather than after.

What you get for $400 to $1,500 is a diagnosis and a specification. An engineer identifies the mechanism, states whether the element remains adequate, specifies the repair method and materials, and gives you something a contractor can price against, which converts a set of differing opinions into a single scope that quotes can be compared on. That alone frequently saves more than the fee. It also removes the guesswork from comparing quotes.

Where building work follows, the regulatory framework applies as normal. Structural work generally requires a building permit under the Building Act 2011 and Building Regulations 2012, with the national framework administered through abcb.gov.au and Western Australian legislation published at legislation.wa.gov.au.

Colour and Appearance After Repair

Every concrete repair is visible and setting expectations honestly is part of a good contractor's job. New material against weathered material differs in colour, texture and reflectance regardless of how carefully it is matched, and the difference is most obvious in the first year before the repair has weathered at all.

Placement decides how much it bothers you. A repair cut to a joint line, a pattern line or a panel edge reads as a deliberate module, while a rectangular patch in the middle of an open area announces itself permanently, so the extra saw cutting to reach a logical line is almost always worth the small additional cost. Discuss where the cut will be before work starts. It is a five minute conversation with a lasting visual consequence.

On decorative surfaces the limitation is more severe. Exposed aggregate, stamped, coloured and liquid limestone finishes all depend on effects that cannot be replicated on a small patch by hand, so repairs to those surfaces are visible for years and sometimes permanently. Owners sometimes choose to accept a crack rather than trade it for an obvious patch. That is a legitimate decision rather than neglect.

Where appearance matters more than the crack does, resurfacing the whole area is an alternative worth pricing. A coating or overlay across a sound slab gives a uniform surface and hides a repaired crack far better than a patch ever will, provided the crack is dormant and the slab is stable. That decision is set out at concrete resurfacing costs.

Repair or Replace

The decision comes down to three questions asked in order. Is the slab structurally sound beneath the visible problem, is the underlying cause fixed or fixable, and is the cost of repair a sensible fraction of replacement. Where all three answers are yes, repair is the right call, and where any is no, money spent on repair buys a delay rather than a solution. Work through them in order rather than starting with price.

A useful rule of thumb is proportion. Where repairs approach roughly half the cost of replacing the area, replacement usually wins on a whole of life basis, because a new slab starts a fresh service life with no history and no patches, while a heavily repaired slab remains a heavily repaired slab. That calculation shifts if the existing finish is decorative and expensive to reproduce. Matching an old exposed aggregate is close to impossible.

Age and remaining life matter too. Repairing a forty year old driveway that is thin, unreinforced and cracking in several places is postponing an inevitable decision, whereas repairing an eight year old slab with one shrinkage crack is straightforwardly sensible. Ask how much of the area is affected rather than looking only at the worst spot. Three cracks in a driveway tell a different story from one.

Where replacement is the answer, it is the moment to fix what caused the failure. Correcting drainage, improving the base, increasing thickness for the actual load, and setting a proper joint layout are all cheap while the area is open and impossible afterwards. New driveway options are set out at concrete driveway costs. Getting the thickness right for the actual vehicles is the main upgrade worth paying for.

Preventing the Next One

Most of what causes concrete failure is decided before the concrete arrives, so prevention is mainly about specification. A properly compacted base, mesh supported on chairs at the correct height, adequate thickness for the actual load, a considered joint layout and a managed cure between them prevent the majority of what people later pay to repair.

Curing is the step most often rushed and the one that matters most in Perth. A hot day with a strong easterly pulls water out of a fresh slab faster than the concrete can use it, and protecting the surface with curing compound, water or covers for the first days develops the strength and durability that resist cracking for decades. A crew that pours at midday in February without a curing plan is creating future repair work. Ask what the curing plan is before the pour rather than after the cracks.

Ongoing maintenance is undemanding but not zero. Keeping joints sealed, keeping water away from slab edges, clearing soakwells, watching what trees are doing and resealing decorative surfaces on schedule together cost very little and prevent most of the expensive outcomes. Put joint inspection on the same cycle as gutter cleaning. Both are autumn jobs and both prevent winter problems.

Where an extension, a shed or new hardstand is planned, think about how it interacts with existing concrete. New slabs poured against old ones need isolation joints, new roof area needs drainage capacity, and new loads need appropriate thickness, all of which are easy at design stage. Extension planning is covered at home extensions.

Contractors and Your Rights

Concrete repair is carried out by general concreters, specialist repair contractors, and in the case of structural remediation by contractors working to an engineer's specification. There is no separate licence for concreting in Western Australia, so the practical checks matter. Ask how they determined the cause, what method they propose and why, what product they will use, and what they expect the repair to achieve and for how long.

The diagnosis question is the one that separates them. A contractor who looks at a crack, runs a straight edge across it, asks when it appeared and asks about drainage before quoting is working properly, while one who quotes a filling price without any of that has priced a task rather than solved a problem. Vagueness about cause is the warning sign. So is a quote produced without anyone visiting the site.

Cutting and grinding concrete generates respirable crystalline silica, which is a serious health hazard, and the contractor carries duties around controlling it. Dust control obligations including water suppression and on tool extraction are set out in codes of practice published through safeworkaustralia.gov.au, with enforcement in Western Australia by worksafe.wa.gov.au under the Work Health and Safety Act 2020.

Consumer guarantees under the Australian Consumer Law apply and cannot be contracted out of. Services must be provided with due care and skill, be fit for the purpose you made known and be delivered within a reasonable time, with the framework administered through accc.gov.au. A repair that fails because the contractor filled a moving crack without saying so is a different matter from one that fails because a tree kept growing. Which of those it is usually comes down to what was written in the quote.

Perth Metro Costs

Rates across the Perth metropolitan area are fairly consistent, and what varies is the diagnosis rather than the labour. Two contractors looking at the same crack can propose repairs differing by a factor of ten, which is why understanding the cause yourself before you collect quotes is more valuable on this job than on almost any other. Ten minutes with a straight edge changes the conversation.

Growth corridor suburbs mostly present shrinkage cracking on relatively young slabs, which is the cheapest category of repair. Slabs there are ten to twenty years old, laid on sand with reasonable base work, and the cracks are generally dormant and straightforward to route and fill. The main thing to check is whether jointing was adequate in the first place. Cracks appearing midway between widely spaced joints are the giveaway.

The coastal western suburbs skew toward spalling rather than cracking, and the cost profile changes accordingly. Salt exposure, older structures, balconies and suspended elements, and inadequate cover on work from earlier decades all push jobs into the repair mortar and steel treatment category, which is priced by area and involves considerably more labour. Assessment is more often warranted there. A cover meter survey before repairing is money well spent on a coastal balcony. It tells you whether you are repairing a defect or starting a programme.

Perth Hills and the eastern suburbs bring reactive clay movement into the picture. Cracks there are more likely to be seasonal, more likely to require monitoring before repair, and more likely to need the drainage addressed rather than just the crack filled. Access and slope add to the cost as well. Getting equipment to a rear yard on a Hills block is rarely simple. Where retaining is involved, see retaining wall costs.

Regional WA Costs

Country repairs price above the metropolitan figure and the driver is mobilisation rather than materials. Crack repair is a small value job by nature, so travelling an hour each way to route and fill six metres of crack is uneconomic, and regional contractors price accordingly or decline the work entirely.

Batching a small quantity of repair mortar or concrete is a regional constraint in its own right. Where a replacement section needs ready mixed concrete, the minimum load charge on a small pour can exceed the value of the concrete several times over, which pushes contractors toward bagged product mixed on site for small work. Ask which approach is proposed. Bagged product mixed on site is perfectly appropriate for small repairs.

Combining work is the reliable saving. Getting the cracks routed, the joints resealed and any other concrete attention done in one visit rather than three spreads the mobilisation across the whole scope, and country contractors will generally price a combined job noticeably better. Walk the property and list everything before you ring anyone. One visit doing five things always beats five visits doing one.

Coastal regional centres carry the same spalling profile as coastal Perth and sometimes worse. Geraldton, Albany, Esperance, Karratha and Port Hedland all sit in aggressive marine environments, and reinforced concrete there deteriorates faster than inland equivalents of the same age. Protective treatment before spalling starts is worth more there than almost anywhere. By the time the concrete is falling off, the cheap option has passed.

What to Look Out For

Run a straight edge across the crack before you do anything else. A crack where both sides remain level is shrinkage and has a cheap permanent fix, while a crack with a vertical step means the ground has moved and filling it buys a season at best. This thirty second test is the single most valuable thing on this page. Do it before you ring anyone.

Be wary of any quote that does not identify a cause. A contractor who prices filling without asking when the crack appeared, checking the falls, looking at the downpipes or running a straight edge across it has priced a task rather than diagnosed a problem, and the repair is being sold on hope. Ask directly what they think caused it. An honest 'I would want to monitor it first' is a better answer than a confident guess.

Check that routing is included rather than just filling. Smearing compound into an uncut crack gives it nothing to bond to and no depth to flex within, so it fails within a year and often falls out in pieces, and the cutting step is what makes the repair last. If the quote does not mention cutting or routing, ask why.

Question injection where a routed repair would do. Injection at $60 to $180 a lineal metre is the right answer far less often than it is proposed. Epoxy and polyurethane injection at $60 to $180 a lineal metre is the right answer for through cracks needing structural bonding or water sealing, and the wrong answer for a dormant surface crack on a domestic driveway. Ask what the injection achieves that routing would not.

On spalling, confirm the steel will be cleaned and treated rather than patched over. Repair mortar applied over rusted reinforcement traps the corrosion and the patch fails within a couple of years, so the sequence of removing unsound concrete, cleaning the steel back to bright metal and treating it before rebuilding is what makes the repair permanent. Expect the repair area to be larger than the visible damage. Concrete around a corroding bar is compromised even where it still looks sound.

Fix the water before you fix the concrete. A downpipe discharging beside a slab, a silted soakwell, reticulation spraying an edge or ground falling toward the house will undermine any repair, and correcting drainage costs hundreds where a settled slab costs thousands. Watch the property during the first serious downpour of winter. Ten minutes standing outside answers most drainage questions.

What to Look for in a Quote in WA

A concrete repair quote should state the diagnosed cause, the repair method and why it suits that cause, the lineal metres or area involved, whether routing or cutting is included, the product to be used by name, how the finished repair will be terminated and finished, and what the contractor expects it to achieve. Any recommended drainage or ground work wants its own line. A quote without a stated cause is not comparable to one that has one. Ask for it in writing rather than as a passing remark on site.

Brief every contractor identically or the comparison is meaningless. Tell them when the cracking appeared, whether it has grown, what the slab is used for, its approximate age, whether anything nearby has changed, and what you have observed during rain. Send photographs with a ruler in frame and a straight edge across the crack, since that image answers half their questions before they arrive. It also tends to produce a more serious response.

Expect the quotes to differ in method rather than only in price, and treat that as information. Where one contractor proposes routing and filling at a few hundred dollars and another proposes injection at several thousand, they are describing different diagnoses, and the useful next step is asking each to justify theirs rather than simply taking the cheaper. That conversation often reveals which one has actually looked.

Settle the cause, the method, the drainage and the expectations before work starts. Confirm what is driving the crack, agree the repair suits it, fix whatever water is contributing, and get a realistic statement of what the repair will look like and how long it should last. With those four resolved, most concrete repairs are good value. Where the assessment says the slab has had its day, the replacement path starts at concreting services.