Asbestos Roof Removal Services WA 2026 - Get Quotes

Identifying an Asbestos Roof

The starting point is the age of the building, not what the sheeting looks like. Asbestos cement products were used extensively in Australian construction until the 1980s and were not fully banned nationally until the end of 2003, so any cement sheet roof on a building constructed or re-roofed before about 1990 should be presumed to contain asbestos until a laboratory says otherwise. That presumption is not alarmism, it is simply the safe working assumption every licensed removalist starts from. The asbestos removal guide for WA covers the broader range of asbestos work in this state. Starting from the build date rather than the appearance avoids most of the confusion in this area. If the building predates 1990 and has cement sheeting on it, assume the worst until testing says otherwise.

The most recognisable roofing product is large profile corrugated cement sheet, widely used on sheds, garages, patios, carports, farm buildings and a great many houses across Perth and regional Western Australia. It is grey when unpainted, noticeably heavier and more rigid than modern metal, and it develops a characteristically weathered, slightly chalky surface with age. Flat and low profile cement sheet also appears on some roofs and on eaves, and both may contain asbestos. None of that is diagnostic on its own, which is the point. Plenty of modern fibre cement sheeting looks broadly similar to the untrained eye, and some older roofs have been overclad or repaired in more than one material.

Nobody can confirm asbestos by eye, including experienced tradespeople, because modern fibre cement looks broadly similar and the difference is in the fibre. The only reliable answer comes from a sample analysed by an accredited laboratory, which costs $80 to $250 and takes a few days. Samples must be taken safely rather than by snapping off a corner, which is why an asbestos testing and inspection service is the sensible route. Breaking a piece off a weathered sheet is exactly the sort of disturbance that releases fibres, and doing it on a ladder makes it worse. On a roof in particular, the sampling itself is work at height on a brittle surface.

Western Australia has a particular history with this material that is worth knowing. Crocidolite, the blue asbestos considered the most hazardous form, was mined at Wittenoom in the Pilbara until 1966, and the state has carried the consequences ever since. The site was eventually degazetted and the town closed, and the legacy remains part of why asbestos is taken so seriously in Western Australia. Asbestos cement building products were manufactured and used widely here, and the housing stock reflects that. A large share of Perth homes built between the 1950s and the early 1980s contain the material somewhere, most often in the outbuildings, the eaves or on a patio roof. It is one of the reasons WA regulators and health authorities treat the material with the seriousness they do. It also means the state has more experienced licensed removalists per capita than most, which works in an owner's favour when getting quotes. Competent operators are not hard to find here.

Where you find it on a property often extends beyond the main roof, and it is worth walking the whole block before getting quotes. Patio and carport roofing, garden shed roofs, the eaves and gable infills, fences, the sheeting behind a fuel stove and flue casings can all contain asbestos on a pre-1990 property. A removalist quoting the house roof should be asked to look at the outbuildings while they are there, because mobilising once is considerably cheaper than twice. Setup, notification and disposal runs all get shared across a larger scope. Many WA properties have more square metres of it on the shed than on the house.

A building or asbestos inspection produces a written record of what is present and where, which is genuinely useful beyond the immediate job. It supports quoting, it tells future trades what to avoid, and it matters at sale time when a buyer's inspector raises the question. Where a property is being purchased, a building inspection will usually flag suspected asbestos materials for further investigation. That flag is a prompt to test rather than a reason to walk away, since a great many perfectly good WA homes contain some. Having the report in hand puts you in a much stronger position on price and timing.

Why Roofs Are Treated Differently

Asbestos containing materials are classified as either non friable or friable, and the distinction drives everything about how they are handled. Non friable material has the fibres bound in a matrix, typically cement, so they are not readily released while the product is intact, which is the category the corrugated sheeting sold in this country as Super Six falls into. Friable material can be crumbled by hand pressure and releases fibres easily, which requires a higher licence class, stricter controls and air monitoring. Intact cement sheet is non friable, which is why an undamaged wall sheet is a low risk item while left alone. A roof, however, does not stay intact indefinitely. Time and weather do the damage that a person would otherwise have to do deliberately.

A roof is the harshest environment on any building and that changes the classification over time. Decades of ultraviolet exposure, thermal cycling, wind driven sand and, along the WA coast, salt all erode the cement binder at the surface, leaving the fibres progressively less bound. The surface becomes chalky, the sheet becomes brittle, and material that began as clearly non friable can deteriorate to the point where it is treated as friable. That is a matter of assessment rather than assumption, and a competent removalist will make a judgement on site. Coastal properties across Perth generally show that deterioration sooner than inland ones.

The practical consequence for an owner is cost and process. Friable removal requires a Class A licensed removalist, an exclusion zone with more rigorous controls, and air monitoring by an independent licensed asbestos assessor, all of which costs more than non friable work. The controls are proportionate to the fact that fibres are more readily released once the binder has broken down. That is not a contractor inflating the job, it is the classification driving the requirements. A removalist who explains why they have assessed a roof as they have is doing the job properly.

Weathering is also why certain activities are absolutely prohibited on these roofs. High pressure cleaning blasts the degraded surface layer off and disperses fibres across the property and the neighbours, which is why roof cleaning and roof painting contractors must establish what a pre-1990 roof is made of before touching it. Power tools, grinders, sanding, wire brushing and dry sweeping of debris are equally out, because every one of them generates airborne dust from a material that should never be made dusty. Even a domestic vacuum cleaner is the wrong tool, since standard filters pass the fibres straight through. The roof cleaning page is worth reading alongside this if a clean was what you originally had in mind. The same applies to roof painting, since a coating job on an untested pre-1990 roof is not something to proceed with.

Physical fragility is the other roof specific issue and it kills people independently of any fibre risk. Cement sheet roofing will not reliably carry a person's weight, particularly once weathered, and falls through brittle roofing remain a recurring cause of serious injury and death in Australian construction. Licensed removalists work from above using roof ladders, crawl boards, harness systems or elevated work platforms so nobody puts weight on the sheets. Spreading load across purlins rather than onto the sheeting itself is the basic technique, and it is not something to improvise. This is a second and entirely separate reason that a homeowner should not be up there. Falls through brittle roofing are not survivable as often as people assume. It remains one of the recurring causes of death in Australian construction.

Storm damage creates the urgent version of this problem and WA gets its share. A sheet cracked or lifted by wind, or debris strewn across a yard after a storm, means broken edges and exposed fibres in an uncontrolled situation. The right response is to keep people and animals away, avoid walking on or sweeping up the pieces, and call a licensed removalist promptly. Wetting the material lightly with a fine spray reduces fibre release while you wait, and the roof repairs page covers making the building weathertight afterwards. Do not attempt to gather the pieces yourself, however tempting it is to tidy up.

Licensing and the Western Australian Rules

Asbestos removal work in Western Australia is regulated under the state's work health and safety framework, administered by WorkSafe WA. Removal licences come in two classes, with Class B covering non friable material and Class A covering friable material as well. A licensed removalist must be engaged for anything beyond the small quantity threshold, and the licence is held by the business with competent supervisors and workers under it. Asking for the licence number and checking it is entirely normal practice.

The quantity threshold is the rule owners most often ask about. Unlicensed removal of non friable asbestos is limited to small quantities, commonly expressed as ten square metres, and every roof exceeds that many times over. A single garden shed roof is typically well beyond it, let alone a house. The relevant regulations can be read through Western Australian Legislation, and the practical answer for any roof is that licensed removal applies. There is no realistic reading of the rules under which a homeowner may take off their own roof.

Licensed removal carries a notification requirement. The removalist must notify the regulator before work begins, typically several days in advance, which is one reason a legitimate operator cannot start tomorrow morning on a whim. That notice period is a useful signal in itself, since an operator offering to turn up immediately and take a roof off may not be going through the process. Emergency situations are handled differently, but a planned removal follows the notification path.

Residential properties sit within a slightly different framework from workplaces, and the Department of Health along with local government both have roles alongside WorkSafe. Local governments in Western Australia deal with asbestos issues on residential land, illegal dumping and public health complaints, and they are the first point of contact where a neighbour's deteriorating roof is a concern. The state government publishes information on where different responsibilities sit. In practice, for a homeowner engaging a licensed removalist, the removalist manages the regulatory side.

National guidance underpins the state rules and is worth knowing about. Safe Work Australia develops the model work health and safety laws and the codes of practice for asbestos removal that the states adopt, and those codes set out the control measures a removalist should be following. The Asbestos and Silica Safety and Eradication Agency publishes public information on identifying and managing asbestos in homes. Between them they explain what good practice looks like without requiring an owner to read the regulations. Reading a little before quoting makes the conversations considerably more productive. You do not need technical knowledge, only enough to ask the right questions.

Penalties for doing this incorrectly are substantial and they apply to owners as well as contractors. Unlicensed removal beyond the threshold, improper disposal and illegal dumping all attract significant fines in Western Australia, and dumping asbestos waste is treated seriously by both local government and the state. There is no version of this where saving money on disposal works out. A legitimate quote includes tracked disposal to a licensed facility, and the paperwork proves it.

How a Removal Runs

A licensed roof removal follows a defined sequence and it is worth knowing what to expect. The removalist inspects and assesses the material, prepares a removal control plan, notifies the regulator, sets up the site with signage and an exclusion zone, removes the sheeting whole wherever possible, decontaminates the area and equipment, wraps and loads the waste, arranges a clearance inspection and provides the documentation. On a typical shed or house roof the on site work runs one to three days. Weather delays it, since removal in high wind is not done.

Site preparation is more involved than most owners expect. Ground sheeting is laid beneath the work area to catch debris, exclusion zones are established with signage and barriers, windows and vents on the building are closed and sometimes sealed, and neighbouring properties are considered in the setup. Evaporative air conditioners in particular should be switched off, since they draw outside air straight into the house. Outdoor furniture, vehicles, play equipment, pet enclosures, vegetable gardens and swimming pools all need protecting or clearing. A removalist who walks the property and discusses all of this before the day is running a proper job. It also gives you time to move what needs moving, instead of doing it in a hurry on the morning.

The removal itself relies on keeping sheets intact. Fixings are removed rather than sheets being broken free, the material is lowered rather than dropped, and the surface is kept damp with a fine water spray or treated with a sealant to suppress fibre release. Breaking sheets is avoided because every fracture creates fresh exposed edges. Whole sheet removal is slower than demolition and that difference in method is a large part of what you are paying for. Anyone proposing to simply pull the roof off quickly has misunderstood the job.

What sits under the roof frequently becomes part of the job. Dust and debris accumulate in the roof space over decades and where a cement sheet roof has been deteriorating, that debris may be contaminated, along with any ceiling insulation. Removing contaminated insulation is a separate scope with its own cost, typically $1,200 to $4,800, and it is one of the more common variations on this work. Where the ceiling space is being cleared anyway, new ceiling insulation afterwards is an obvious pairing. Older Perth homes are frequently under insulated, so the upgrade is worth taking while the access exists.

Decontamination closes out the removal stage. Tools, equipment and protective clothing are decontaminated or disposed of as asbestos waste, the work area is cleaned using wet methods and specialised vacuums rather than sweeping or domestic vacuum cleaners, and the ground sheeting is wrapped and disposed of with the sheets. This stage is easy to skimp on and difficult for an owner to assess. It is one reason the clearance inspection by an independent party matters. Nobody should be signing off on their own work at this stage. Independence is the entire value of the clearance.

Waste handling has its own requirements from the moment a sheet comes off. Material is wrapped in heavy duty plastic, sealed and labelled, loaded without breaking and transported to a facility licensed to accept asbestos. Not every landfill takes it, and in regional Western Australia the nearest accepting facility can be a considerable distance away, which is why regional quotes carry higher disposal costs. Cartage is often the single largest component of a country job. Ask which facility the waste is going to and expect a straight answer in writing.

Weatherproofing between removal and replacement needs to be planned in advance. Once the old roof is off, the building is open, and in a Perth winter that is not a position to be in for long. The usual approach is to remove and re-roof in a coordinated sequence, often with the roofing contractor following immediately behind the removalist, or with temporary cover in place. On a house this is more than a scheduling preference, since furniture, ceilings and wiring are all exposed while the roof is off. Agreeing who is responsible for the building being watertight overnight is a question worth asking explicitly. It is the single most common gap where two separate contractors are involved.

Clearance and Disposal

A clearance inspection is the independent check that the area is safe to reoccupy, and it should be carried out by someone independent of the removalist. For non friable removal that generally means an independent competent person inspecting visually and issuing a clearance certificate. For friable removal a licensed asbestos assessor is required, and air monitoring forms part of the process. The certificate is the document that says the job was completed properly, and it typically costs $350 to $850.

Keeping the clearance certificate matters more than owners realise at the time. It is the evidence that removal was carried out by a licensed operator and verified afterwards, and it answers the question a buyer's building inspector will eventually ask. It also supports any insurance position and demonstrates due diligence if a question ever arises about how the material was handled. Store it with the property documents where it will be found again, and keep a digital copy as well.

Air monitoring is worth understanding even where it is not mandatory. It involves sampling the air during and after the work to confirm fibre levels are within acceptable limits, and it provides objective evidence instead of a visual opinion. On friable work it is required, and on larger non friable jobs, or where occupants are particularly concerned, it can be arranged voluntarily. Where children are in the house or a neighbour is anxious, it is often worth the additional cost for the reassurance alone.

Disposal is tracked and the documentation should come back to you. Asbestos waste in Western Australia must go to a landfill specifically licensed to receive it, transport is subject to controls, and the receiving facility issues a receipt. A legitimate removalist provides evidence of disposal as part of the job. If a quote is markedly cheaper than others, disposal is one of the places that saving typically comes from, and the material ends up somewhere it should not be. Landfill charges for asbestos are substantial and cannot simply be absorbed.

Illegal dumping is a genuine problem in Western Australia and it is prosecuted. Asbestos dumped on verges, in bushland, on vacant lots or mixed into general waste creates a hazard and a clean up cost that falls on the community, and the penalties reflect that. The Environmental Protection Authority and local governments both have roles in environmental regulation and enforcement in this state. As the property owner, engaging a licensed operator and keeping the disposal evidence is your protection.

Small quantities from an owner's own residential property are handled differently and rules vary by local government. Most Perth councils have arrangements for householders to dispose of small quantities of securely wrapped asbestos at specific facilities, sometimes by appointment and sometimes with a fee. Those arrangements exist because small amounts turn up during ordinary renovations rather than to enable larger work. Those arrangements apply to genuinely small amounts, not to a roof. Check with your own council before assuming, since the requirements and the accepting sites differ between districts.

Replacing the Roof

Removal and replacement are usually planned together, and coordinating the two trades properly is the main project management task. Most households remove an asbestos roof because they are re-roofing anyway, or because deterioration has forced the issue, and the sensible approach is to have the roofing contractor ready to follow the removalist. Some businesses offer both under one contract, which simplifies responsibility considerably. Where one party is accountable for the whole program, the handover gap disappears. Where two separate contractors are involved, agree in writing who covers the building between stages. A day of rain into an open roof space costs more than the coordination would have.

Colorbond steel is the usual replacement across Western Australia and it suits the conditions well, with Lysaght and Stramit the profiles most commonly rolled for the local market. It is light, it handles the UV load, coastal grades are available for salt exposure, and it goes on quickly once the old roof is off. Installed cost commonly runs $75 to $150 a square metre depending on profile, insulation, access and the condition of the roof structure beneath. The roofing services page covers the options and the associated metalwork sits on the roof and gutter plumbing page. Coastal grades matter within a few hundred metres of the water.

The frame underneath needs checking once it is exposed and this is where variations arise. Purlins, battens and rafters on a building old enough to have an asbestos roof are often forty or fifty years old, and rust, termite damage or sagging may be found. Cement sheet is heavier than Colorbond, so a structure that carried it will generally carry the replacement, but the reverse consideration applies if anything heavier is proposed. Budget a contingency for structural repairs so one does not derail the job.

Insulation and ventilation are worth addressing while the roof is off, because the access will never be better. Sarking or a reflective foil layer under a new metal roof makes a substantial difference to summer heat and to condensation, ceiling insulation can be replaced properly rather than worked around, and roof ventilation can be fitted at the same time. The roof ventilation and whirlybird installation page covers that last part. On a hot Perth roof space these measures are more valuable than they sound. Ceiling cavity temperatures here climb well above ambient on a February afternoon. Insulation and ventilation together make a noticeable difference to how the house feels.

Gutters, downpipes and flashings are almost always replaced at the same time. They are the same age as the roof, they are accessible only while the work is underway, and old gutters look conspicuously tired against a new roof. The gutter replacement page covers the choices. Where the new roof changes the runoff arrangement, stormwater disposal may need revisiting as well, since soakwell capacity is calculated from roof area.

Outbuildings deserve a decision at the same time as the house roof. A shed, patio or carport roof of the same vintage will need the same treatment eventually, and mobilising a licensed removalist twice costs considerably more than doing everything in one visit. Where a patio roof is being replaced, the patio and verandah installation page covers the structure side, and the shed and garage construction page covers outbuildings more generally. Many owners take the opportunity to replace an aging patio frame at the same time. Getting all of it quoted together usually produces a better overall price. It also means one set of notifications, one clearance process and one disposal run instead of three of each.

Neighbours, Insurance and Records

Telling the neighbours before work starts is both courteous and practical, and on a narrow Perth block it is close to essential. Asbestos removal involves visible signage, exclusion zones and people in protective suits, and a neighbour who has not been warned will reasonably be alarmed. A short conversation beforehand explaining that the work is licensed, when it is happening and that their property is being considered in the setup prevents most complaints. Suggesting they bring washing in and close windows on the day is a sensible courtesy.

Where a neighbour's roof is the problem rather than your own, the local government is the right first contact. Councils deal with asbestos on residential land as a public health matter and can act where deteriorating material presents a risk. Approaching the neighbour directly and in good faith is usually the better first step, since many owners simply do not realise the condition their shed roof is in. Escalating to the council is available where that does not work, and they are used to dealing with it.

Insurance treats asbestos in a way worth checking before you need to. Home policies typically cover damage from an insured event such as a storm, but the cost of removing and disposing of asbestos safely can be subject to limits or exclusions, and policies differ considerably. Where a storm damages an asbestos roof, contact the insurer before arranging anything and get the position in writing. Photograph the damage thoroughly from a safe distance before anyone touches it. Do not have the material removed and then seek reimbursement without checking first. Claims are considerably harder to argue after the evidence has gone to landfill.

Contractors doing any work on your property should be asked about asbestos awareness, not just removalists. Electricians running cables through a roof space, plumbers installing a hot water system, air conditioning installers and solar panel installers all work in and around materials that may contain asbestos on an older WA home. Telling them what the property contains, and providing any report you have, protects them and you. The solar panel installation page is a relevant example, since panels are frequently fitted to older roofs.

Consumer protections apply to this work as to any other service. The Australian Consumer Law provides guarantees that services will be performed with due care and skill, overseen by the ACCC, and those guarantees sit alongside the regulatory obligations rather than replacing them. Get the scope, the licence details, the disposal arrangements and the clearance process in writing before work starts. A written scope is also what makes comparing quotes possible on a job where the visible outcome looks identical either way.

Keep a complete record afterwards because it has lasting value. The laboratory test results, the removalist's licence details, the removal control plan, the clearance certificate, air monitoring results where applicable, disposal evidence and photographs of the completed work all belong in one file. At sale time this file answers the buyer's questions immediately and leaves no room for doubt or a price adjustment. A property with documented asbestos removal is a materially easier sale than one where nobody can say what happened. Buyers price uncertainty into their offers, and asbestos is one of the things they price most heavily.

Costs in Detail

Laboratory testing of a sample runs $80 to $250 and is the cheapest step in the whole process. A full asbestos inspection and written report covering the property runs $280 to $650 and is worth having where there may be multiple materials or where you are planning staged work. Both are money well spent before committing to a removal, since they establish exactly what is present. Collecting the sample safely is part of what the inspection service provides, which matters when the material is on a roof.

Roof sheeting removal is commonly priced per square metre, running $55 to $115 in the Perth metropolitan area. The spread reflects sheet condition, roof pitch and height, access for equipment and waste handling, and whether the material is assessed as non friable or has deteriorated to the point of requiring Class A controls. Difficult access, two storey work and heavily weathered sheeting all push toward the upper end. Sites where a truck cannot get close enough to load waste directly add handling time as well. Single storey sheds with good access sit at the lower end of the range.

In whole job terms, a shed, patio or carport roof typically runs $1,800 to $4,500 and a house roof $7,500 to $19,000 for removal alone. Those figures include the licensed removal, site setup, waste wrapping and disposal, but the clearance certificate at $350 to $850 is sometimes quoted separately. Contaminated ceiling insulation removal adds $1,200 to $4,800 where it is required. Larger rural properties with multiple outbuildings are quoted as a package across the whole site.

Replacement roofing is a separate budget again. New Colorbond installed runs $75 to $150 a square metre depending on profile, sarking, insulation and access, and structural repairs discovered once the old roof is off are additional. Gutters, downpipes, flashings and any roof ventilation are quoted on top. For a typical Perth house, removal plus a new roof and guttering frequently lands somewhere between $18,000 and $40,000 all up. That is a substantial project, which is why it is usually done once and done properly.

Regional Western Australia is where the disposal component really bites. The nearest landfill licensed to accept asbestos can be hundreds of kilometres from a property in the Wheatbelt, the Goldfields, the Mid West or the Pilbara, and cartage is charged accordingly. Removalist travel and accommodation add further, and on remote sites the mobilisation can approach the cost of the removal itself. Grouping properties or coordinating with neighbours in the same district is common practice and genuinely reduces the cost per property. In farming districts, whole runs of sheds are often done in one mobilisation, which is the only way the economics work.

Be realistic about why one quote might be much cheaper than others. Licensed removal has fixed costs in notification, controls, protective equipment, decontamination, tracked transport and licensed disposal, and none of those are optional. A quote well below the range usually means one of them is being skipped, most often the disposal. That is a risk transferred to you as the property owner rather than a saving, and it is not one worth taking. On a job of this kind the middle of three quotes is very often the sensible choice.

What to Look Out For

Verify the licence before anything else. Asbestos removal in Western Australia requires a licence held by the business, and the class must suit the material, with Class A required for friable work. Ask for the licence number and the class, then check it against the register instead of accepting a laminated card at face value. WorkSafe maintains the register and a short search confirms whether a business currently holds what it claims. Any operator who is vague or defensive about this should not be on the property, whatever else they are offering.

Be very wary of anyone offering to start immediately. Licensed removal requires notification to the regulator before work begins, so a legitimate operator generally cannot begin the next morning on a planned job. An offer to come straight over and take the roof off is a strong indication that the process is not being followed. The exception is genuine emergency work, which is handled differently and will be explained as such by anyone operating properly.

Check that disposal is specified and evidenced. Asbestos waste must be wrapped, labelled, transported under controls and taken to a facility licensed to accept it, and the removalist should be able to name that facility and provide disposal evidence afterwards. A quote that is silent on disposal, or markedly cheaper than others, is the one to question. Illegal dumping is prosecuted and the trail can lead back to the property it came from, which is a genuinely unpleasant position to be in.

Make sure the clearance inspection is independent. The person confirming the area is safe to reoccupy should not be the same party that carried out the removal, since the whole value of the clearance lies in its independence. Ask who will perform it, what their qualification is and when you will receive the certificate. A removalist who arranges an independent clearance as standard is running a proper operation. It is also the document you will be asked for years later, so it needs to exist.

Finally, never let anyone pressure clean, walk on, drill, cut or grind a suspected asbestos roof, including contractors who are on the property for something else entirely. Roof painters, solar installers, antenna technicians and air conditioning installers all end up on older roofs, and the sheeting is both a fibre hazard and a fall hazard. Tell every contractor what the property contains. That one conversation is the most useful protective measure available to an owner, and it takes thirty seconds.

How to Get Comparable Quotes

Start with the facts a removalist needs. The approximate roof area, what the building is, how many storeys, the age of the structure, the apparent condition of the sheeting, whether there is ceiling insulation, what access is available for a vehicle and whether any test results already exist. Photographs from the ground help considerably. If you have had a sample tested, provide the laboratory report with your enquiry, since it removes the main uncertainty from the pricing. Removalists quoting without a result have to allow for the possibility that it comes back friable.

Give every operator the same written list of questions. Licence number and class, how they have assessed the material and why, whether notification to the regulator is included, the site setup and exclusion zone arrangements, how neighbouring properties will be protected, whether contaminated insulation is included or excluded, who performs the clearance inspection and when the certificate is issued, which licensed facility the waste goes to, whether disposal evidence is provided, and how the building is kept watertight before the new roof goes on.

Get the replacement roof quoted at the same time, since pricing it afterwards removes your leverage. Removal and re-roofing are most efficient as one coordinated program, and quoting them together lets you see the full cost and settle responsibility for the building between the two stages. Where one business offers both, ask how the two crews are sequenced. Where they are separate, ask each how they intend to work with the other and who carries the risk in between.

Compare the process rather than only the price on this job more than any other. The cost differences between quotes usually reflect whether disposal, clearance and decontamination are being done properly, and those are precisely the parts you cannot see from the ground afterwards. A quote well below the others is not a bargain on this kind of work. Ask the cheaper operator directly which steps their price includes, and compare the answer against what the others have specified.

Keep everything once the job is done. The test results, licence details, clearance certificate, air monitoring results where relevant, disposal evidence and photographs form a record that has real value at resale and genuine reassurance value in the meantime. Removing an asbestos roof properly is one of the more substantial improvements an owner can make to an older Western Australian property. Being able to prove it was done correctly is most of the benefit, and the paperwork costs nothing to keep.