The mining of asbestos has been ongoing for about four thousand years, but massive production began just before the 20th Century. At the time, it seemed to be the best option. The primary reason for this was its alluring properties both as a fireproof material and as an insulator. In recent years, though, studies have shown that the use of asbestos is by far more harmful and detrimental to both the engineer and the end user than it is beneficial.
For a very long time, particularly since the 1980s, the usage of asbestos as a domestic building material has generally been stopped. However, there was no legal enforcement behind the stoppage in Australia until the 31st of December 2003, when a ban was placed on the use of asbestos by the Australian government. This ban made the importation, exportation, wholesaling or retailing, storing and reprocessing of asbestos an illegal act in Australia.
What is Asbestos?
The word "asbestos" is of Greek etymology and is written in Greek as ἄσβεστος meaning unquenchable. Asbestos is a compound material, meaning that it doesn’t exist in isolation. Scientifically, asbestos can be referred to as a group of six silica or silicate minerals which exist naturally and are found in the same asbestiform habitat. The asbestiform habitat is a lengthy and tiny fibrous crystal comprising of millions of fibrils which are microscopic in nature.
In building and construction engineering, the term "asbestos" is used in reference to materials which contain many fibrous minerals of magnesium silicate. These minerals include actinolite, tremolite, crocidolite, amosite, anthophyllite, and chrysotile. They are used for making different things such as roofing sheets, fireproof gloves, plumbing materials, electrical materials, linings of brakes, etc.
Types of Asbestos?
Prior to the modern day system of classification, there were basically three types of asbestos. The three types of asbestos were blue asbestos, white asbestos and brown asbestos. However, the new system of classification groups the material into two major classes.
1. The Serpentine Class of Asbestos which comprises of chrysotile.
2. The Amphibole Class of Asbestos, which comprises of actinolite, tremolite, crocidolite, amosite and anthophyllite.
This is also called white fiber because of its whitish appearance when viewed with a microscope. Chrysotile is gotten from serpentine rocks. The uniqueness of chrysotile is its flexibility. This flexibility allows it to be used in various ways. Chrysotile has been the most widely used type of asbestos in Australia, comprising more than 50 per cent of all asbestos used. It has been mostly used for roofing, panels of ceilings, walls, and floors. It was also used in the construction of garages and warehouses.
In appearance, actinolites are naturally dark. They are light fibers and dynamic fibers. Sometimes they are compact, sometimes they are brittle and sometimes they are dense. They are elastic in nature.
Tremolite fibers are fragile fibers. They can be woven into different shapes. They occur in multiple colors but are mostly green, grey or white.
Crocidolite is also known as blue asbestos. It is the fibrous form of riebeckite amphibole. Crocidolite is readily found in Australia. It is also common in the southern axis of Africa.
Amosite is also called brown asbestos though it is seen as a greyish white fiber under a microscope. Amosite is the collective name for the amphiboles that fall under cummingtonite-grunerite solids.
Anthophyllite are greyish brown in appearance. They are used for flirting and talcum powders. Research has shown that the adverse effect of using anthophyllite is milder in comparison with the others. Nevertheless, it is still harmful.
It is important to note that all six mineral types in the Amphibole Class of Asbestos are human carcinogens.
Asbestos Cladding and Ceiling Batts
Asbestos cladding is simply the covering of the outer parts of walls, roofs, floors, etc with an asbestos coating. Asbestos cladding was a popular trend in the architecture of old structures. Then, construction engineers made use of asbestos to clad roofing sheets. Local asbestos cement sheets were used because they were easy to install.
Asbestos was also used as ceiling batts. A ceiling batt, or insulation batt, is a type of bulk insulation that is designed to fit between joists, rafters or studs. They fit very snugly into these without leaving gaps that can compromise the efficiency of the insulation. Ceiling batts have millions of tiny pockets that trap air, and this helps to reduce the transfer of heat so that it is warmer in the winter and cooler in the summer. They can also help to reduce the passage of sound, so they can be used as acoustic insulation in some cases as well. The downside of using asbestos for ceiling batts is that it makes its removal very dangerous when it wears out.
Nowadays, the trend of using asbestos in ceiling batts is ancient and very frowned up, if not illegal, especially in jurisdictions such as the United Kingdom, Australia, and the United States which have prohibited the use of asbestos. In addition to the fact that asbestos usage is considered criminal, it poses a serious health threat. When the surface of asbestos materials corrode they can cause the release of toxic fibers into the air. Asbestos has also be traced to be a root cause of some life-threatening diseases like lung cancer, cancer of the abdomen and asbestosis.
Statistics of Asbestos in Australia
For many years preceding the mid-1980s, Australia recorded the highest number of asbestos users in the world. About one of every four houses in Australia contain asbestos materials, and if a house was built in the 1990s, the likelihood of it containing asbestos material is more. Up until 1984 Australia mined asbestos. From 1930 to 1983 about 1.5million tonnes were imported. The Australian Asbestos Safety and Eradication Agency stipulated in a report that homes built before the 1980s have a high content of asbestos materials while those built between mid-1980s and 1990 contain some asbestos materials and those built after 1990 have little or no asbestos materials.
Australia is rated the second country in the world with the highest recorded mesothelioma death rate. Every year in Australia at least six hundred people are diagnosed with mesothelioma caused by asbestos materials. The statistics of mesothelioma patients in Australia are similar to that of other parts of the world. In 2014, the Australian Mesothelioma Registry recorded 641 deaths in Australia (80% of them were men, and 20% were women, and they were about 70-79 years old). New South Wales had the highest production of asbestos in Australia and has recorded the highest number of deaths resulting from mesothelioma. The frequency of death doubled between 1987 and 2006 in New South Wales. Other states like Tasmania, Western Australia, Queensland, Victoria, and South Australia also have high rates of mesothelioma deaths.
In 2003, Australia placed a ban on asbestos materials. Regardless, residents are still threatened by mesothelioma and other asbestos-related diseases because, and despite the bans, residents remain at risk for mesothelioma because of the residue and remnants of the old materials which were used in buildings. Cancer experts predict that about 6,800 people in Australia may die from asbestos-related cancer in the next decade.
A Brief Description of Asbestos Usage and Its Effects in Australia
In Australia, it is the non-friable asbestos that is mostly found – and this is very dangerous. The cases of health hazards and deaths caused by asbestos skyrocketed in 2004. The unprecedented amount of deaths caused by the negligence of the renowned James Hardie Industries led to the largest personal injury settlement in Australia. This case was referred to as the ‘first wave of the asbestos saga’ which comprised of many victims and their loved ones who lived in homes and worked in commercial buildings containing asbestos. The second wave consisted of people who worked with asbestos, that mined, bought or sold asbestos materials. This second wave of people were the next to feel the adverse effects of the harmful material. A few years ago, an Australian Television network reported that the third wave would be people who wish to renovate their homes or take out the asbestos material. According to Professor Nick Van Wijk, the issue is not a thing of the past; it is as serious issue which is very present in our current lives.
Importance of Reporting Asbestos
1. Health Danger
Breathing in asbestos can be extremely harmful and dangerous for your health. As innocent as it looks, it can be very detrimental to your health causing diseases like lung cancer, asbestosis and mesothelioma. Currently, asbestos has been seen as the cause behind an estimated two hundred and fifty thousand deaths annually. Every fibre of asbestos, no matter how small, possesses a health threat and if you do nothing about it, you're taking a huge risk. Some people have said that the material itself doesn’t do any harm if it is left untouched, but that has been proven to be a false statement. Research has shown that when water washes the outer layers of the asbestos, it carries along with it some dangerous particles.
Carol Klintfall told her story on Australian National Television. She is a victim of mesothelioma. She contracted the disease from inhaling particles of asbestos which were dispersed into the air. According to her, the health threats of asbestos should not be taken lightly. The disease has no respect for the old or young, it doesn't discriminate, and anyone can be a victim. She emphasized the need for the government of Australia and private individuals to address the issue with all sense of seriousness.
2. Legal Implication
By law, the Australian government has prohibited the importation, sale, retention, storage, and use of asbestos. The Work, Health, Safety and Environmental Laws in all States and Territories in Australia have taken the enactment and enforced the same in their jurisdictions. The only exception to this legal provision is if permission is granted pursuant to Regulation 4C of the Customs (Prohibited Imports) Regulations 1956, or in a case of a lawful exception pursuant to Regulation 4, and Part 1 of Schedule 1 of the Customs (Prohibited Exports) Regulations 1958.
Australia's ban on the use of asbestos is comprehensive and covers all types of asbestos. Even goods which are termed "asbestos free" are rarely allowed in Australia, or only on very rare occasions.
In consideration of the illegality involved in using asbestos, it is of utmost importance that you report its use to the relevant agencies.
3. Asbestos register
If you manage or control a workplace, it’s your responsibility to ensure an asbestos register is prepared, maintained and kept at the workplace.
An asbestos register is a document that lists all identified—or assumed—asbestos in a workplace.
The asbestos register must:
• record any asbestos that has been identified or is assumed to be present at the workplace
• record the date when the asbestos was identified
• record the location, type and condition of the asbestos
• be maintained to ensure up-to-date information
• be given to the employer or business (or other PCBU) when there is a change of management or controller of the workplace.
An asbestos register may also contain information such as:
• details about asbestos that is assumed to be present at the workplace
• analysis results confirming whether asbestos is at the workplace
• details of inaccessible areas.
Where possible asbestos must be labelled. For example, a label can be placed in the electrical meter box indicating that the building contains asbestos and the location of the register.
Photographs or drawings are useful for showing the location of asbestos in the workplace.
An asbestos register is not required for a workplace if:
• it was a building constructed after 31 December 2003
• no asbestos has been identified in the workplace
• no asbestos is likely to be present at the workplace from time-to-time.
* Information on the Asbestos Register has been obtained from Safe Work Australia.
4. Social Welfare
The general well-being of society at large must be our main priority. We owe it to future generations to ensure that the environment is free from as many health hazards as we can prevent. The wellness of the environment translates into the wellness of the individual.
Why You Need Us
It is recommended that you use a licensed asbestos removalist to remove asbestos from your home or workplace. However, in NSW as long as you take the appropriate safety precautions, you are permitted to remove a maximum of 10 square metres of bonded asbestos. If you are removing more than 10 square metres, you MUST either hire a qualified asbestos removalist or obtain a NSW SafeWork bonded asbestos removal licence which requires you to attend an appropriate training course run by TAFE or a registered training organisation. Any loose or friable asbestos must be removed by a qualified asbestos removalist and cannot be removed by the homeowner.
The last thing you want whilst getting rid of asbestos is to risk exposure to these dangerous particles. Removal of asbestos is no easy work. It requires time, safety equipment and expert skills.
If you would like your property inspected for asbestos, or believe you have asbestos in your commercial or residential property, contact BeSafe Property Inspections to discuss how we can assist you.
Understanding the cause requires consideration of a large number of factors, and is the first step in making any assessment as to the seriousness and cost of repairing wall cracks.
Some of the most common causes of cracking are:
The impact of foundation soils
Some level of soil excavation is usually required when a home is first built. Depending on the type of home you have, will determine how much excavation work needs to be carried out. Some types of homes require more disruption to the soil than others in the course of their construction.
Disturbed soil will compact and settle with time, which can cause a wall to crack. This process can take months or even years to occur. Natural settling will often cause narrow vertical cracks as opposed to big jagged cracks.
Minor settling is a normal process that occurs over time. However, significant downward motion in the soil under a wall may create more serious structural faults. Significant faults can occur when soil is washed away (an example is sudden flooding or slowly over time during a gradual leak), when soil compacts too much or collapses. A powerful example of this is sink holes.
A reactive soil is a type of soil that contracts when it is dry and dramatically expands when moist. A good example of a reactive soil is clay. Examples of non-reactive soil types include bedrock, gravel and sand. To assist in identifying whether the soil on your property is reactive and could be a contributing factor to cracking, soil testing should be undertaken.
Changes occurred by nature and the environment
Intense climate and seasonal changes, such as flood and drought, can cause dramatic contraction and expansion of the soil. Wall cracking can also occur when the water table changes deep below a property.
While earthquakes and earth tremors are infrequent events in Australia, these can also contribute to wall cracks appearing.
Construction and excavation work in your area
If you live in an area where there is a lot of construction work happening, such as a new housing estate, or if you live in close proximity to a quarry then this can be the cause of wall cracking.
The vibration of heavy machinery, excessive mechanical compaction of the soil or blasting (the use of explosives to excavate) can all cause your walls to crack.
If the wall cracking appears during or following construction in your area, you should seek an urgent assessment of the cracks and legal advice.
Design or extension work
If your property was poorly designed (whether it is the initial construction or an extension which has been added), this can cause wall cracking.
The cracking can occur because of too much weight on a load-bearing wall, inferior or faulty building materials, or under-engineered footing design.
Surrounding the property
Blocked or leaking pipes, garden sprinklers or blocked gutters can all cause wall cracks as they can have the effect of saturating or even washing away soil.
Trees can also have invasive root structures that can contribute to wall cracking. It is best to only have small bushes or shrubs in close proximity to your walls. Apart from destructive roots, trees can also contribute to wall cracking by removing water from the soil and affecting the soil’s moisture content.
If you remove a large tree from an area in close proximity to your walls, this can also cause cracking as it can destabilise the soil in the space previously occupied by the root system. It can also lead to changes in the moisture levels of the soil or settling over time.
Nothing lasts forever, and building materials are no exception. Weathering, gravity, poor maintenance or rotting can all take their toll on building materials.
When building material starts to age, its structural integrity might be undermined causing it to succumb to gravity. This can cause wall cracks to appear. If steel reinforcements in concrete starts to rust and degrade following exposure to moisture and salt, this can also cause cracking.
Don’t be complacent. Take photos and document wall cracks. We recommend including a ruler in the frame of the photo so you can easily compare and track the progress of any cracks over time.
According to QBCC Standards & Tolerances Guide 2016 and Australian Standard AS2870, cracks in concrete slabs 2mm or greater and those in masonry or plasterboard walls 5mm or greater (3mm or greater when in groups) may be deemed to be defects.
If the cracks in your walls are the sizes mentioned above, or if you have any concerns about smaller cracks, we recommend that you contact a qualified building inspector for an assessment of the possible cause and severity of the cracks in your walls. They will be able to provide you with a plan of attack and estimate the possible costs of repairs.
Protecting your family’s safety and your financial investment is paramount, and it is important that you take their advice seriously and follow through within the recommended timeframes.
Need to identify the cracks in your wall? Read our article on “Cracks in Buildings. How Serious Are They?”
Concerned about cracks in your walls? Contact BeSafe Property Inspections to discuss your wall crack concerns on(02) 9410 3740 or via our website.
The sight of cracking can set off alarm bells in anyone considering purchasing a property, although, most properties will exhibit cracking at some point in their lives. As materials age and settle to accommodate changes in the building's environment, cracks can appear if the builder has not allowed for this environmental change by installing control or expansion joints.
While cracking is often not a great cause for alarm, affecting only the appearance, some cracking can also be a sign of a serious problem, such as the stability of the building being under threat.
Because of this, all cracking, insignificant or otherwise, should be considered seriously and checked by an expert.
What To Look Out For
Wall cracks fall into three main categories:
- Interior wall cracks which occur in plasterboard or gyprock;
- Exterior wall cracks such as cracks in the surface, brickwork, or in the rendering of external walls;
- Cracks in foundation walls.
All three can be serious and signs of structural failure.
In order to assess how serious the problem really is, you need to look at the location, the type of crack, and whether there is a separation in the materials used to construct the wall or if a separation has appeared between the wall and the framework.
Cracks should also be monitored over time to see if they are smaller or bigger, or staying the same size. A crack that starts off small in size may change into a larger crack, being an indication of more significant movement to the building’s structure that will require remediation.
Shapes Of Cracks
The form and size of the crack can sometimes indicate the underlying problem. Cracking can be horizontal, vertical, stepped, cogged or a combination of all these. When assessing cracks, the width of the crack is often more important than the length of the crack.
Stepped cracks tend to follow the lines of horizontal and vertical joints in buildings, such as beds of mortar between bricks or blocks and may indicate structural movement.
Vertical cracks may indicate that structural components such as bricks or blocks have failed and so can be a sign of significant stresses within the building structure.
Cracks that are wider at the top or at the bottom may indicate that there has been foundation movement, with the direction of the widening giving an indication of the likely direction of the movement.
Horizontal cracks may indicate that an element such as a wall is failing and this may present a safety concern.
As a general rule, the following sizes and descriptions apply:
Damage to Walls caused by movement of Slabs and Footings, and other Causes*
|Crack Width Limit||Typical Description and Repair|
|< 0.1 mm||Hairline cracks|
|< 1 mm||Fine cracks that do not need repair|
|< 5 mm||Cracks noticeable but easily filled. Doors and windows stick slightly.|
|5 mm to 15 mm (or a number of cracks 3 mm or more in one group)||Cracks can be repaired and possibly a small amount of wall will need to be replaced. Doors and windows stick. Service pipes can fracture. Weather tightness often impaired.|
|15 mm to 25 mm but also depends on number of cracks||Extensive repair work involving breaking-out and replacing sections but also depends on walls, especially over doors and windows. Window and door frames distort. Walls lean or bulge noticeably, some loss of bearing in beams. Service pipes disrupted.|
* Guide to Standards & Tolerances 2015, Building Commission
Cause And Action
Cracks fall into 3 main categories.
Category 1: Small (Minor) Cracks - includes hairline cracks <.1 mm and fine cracks <1 mm including cornice cracks
The most common cracks you will find in buildings are hairline cracks, particularly in plaster, which is prone to shrink and is very sensitive to movement.
The main cause is often settlement of the walls onto the foundations or movement in the building associated with changes in moisture and/or temperature.
Most of the time small cracks don’t require any specific repair, as the issue is likely to only be cosmetic.
If required, you can engage a contractor to do the job but most hairline cracks can be resolved with a DIY job.
It might seem counter-productive, but first you should create a deeper hairline crack (using a screwdriver, scraper or utility knife) before starting the repair work. This “opens up” the crack so that you can clean out the loose paint, debris, concrete or old filler (using a dry brush, cloth or vacuum) before mending. This also helps the filling solution to properly fill the insides of the crack.
After cleaning the crack, fill it with filling solution/joint compound. Make sure the filler covers the entire crack.
Even out the surface with your scraper and let the filling dry out for a day. Don’t rush the process!
Once the surface has dried, sand it down so the surface is completely smooth and even.
Then apply paint. If you are applying two coats, always make sure the first coat has properly dried before applying the second coat.
Category 2: Medium Cracks – includes cracks from 1 mm to 5 mm
Whilst aesthetically concerning, cracks up to 5mm can generally be patched and painted. In newer homes the cracking almost inevitably relates to settlement and or vibratory action from within or adjacent properties. With older properties it can be the onset of one of the key contributing factors associated with Category 3 cracking (see below).
In addition, one of the major contributors to wall cracking is when downpipes are not connected to soak wells, the concentration of water around the footings at the downpipe positions can lead to subsidence of the footings and cracking of the house walls.
The key issue with category 2 cracks is to determine significant changes over a relatively short period of time, say 6 – 12 months (or even shorter). If the cracking gets worse, preventative action should be taken sooner rather than.
If there are any significant contributory causes to the cracking, like rusting lintels or significant cracking to concrete which is facilitating water ingress, preventative action should be taken immediately. While the cracking may only be minor now, unless the underlying issue is addressed it will only get worse. Taking care of the cause is more important than fixing the crack itself.
It is also very important to monitor any changes in the crack over time. Once you become aware of a crack, your eyes will constantly be drawn to it and it can often seem like the crack is getting bigger. Photography can greatly assist with monitoring cracks. By using your smart phone or digital camera (ensuring the date stamp is turned on), you can take regular pictures of the cracking and monitor changes. It is a good idea to place a coin or ruler next to the crack as a point of reference to properly determine whether the crack is growing.
Category 3: Large (Moderate to Severe) – includes cracks from 5 mm to 25 mm
Category 3 cracks are important to address immediately as there could be a significant safety issue. There can be a range of issues which can cause severe cracking, such as:
- Issues with footings and or concrete pads (subsidence)
- Water ingress, moisture/damp in the walls
- Concrete cancer and rusting lintels
- Impact damage
- Issues associated with the roof frame or other load bearing problems
- Concentration of water around the footings
As a general rule, cracks within this category shouldn’t be ignored and left untreated. At the smaller end of the scale, the crack needs to be filled to avoid any potential water ingress, particularly if it is an external wall. At the other end of the scale, the wall may need to be inspected by a structural engineer to determine what remediation work is required. There is a possibility that a section of a wall needs to be rebuilt.
At the very least, an inspection by a professional and a plan of action needs to be determined – and acted upon as soon as possible.
Do you want to better understand what causing cracking? Read our article on “The Cause Of Wall Cracks”.
Concerned about cracks in your walls? Contact BeSafe Property Inspections to discuss your wall crack concerns on (02) 9410 3740 or via our website.