If you're looking to install a new garage, you may need to work out how to deal with the old one first. Demolishing a brick garage may seem like a relatively easy task, but if the original builders used an asbestos roof, the job could become much more complex. Asbestos is a dangerous material that can cause serious human health problems. Learn more about the dangers of asbestos, and what you need to do to safely dispose of an asbestos garage roof.

Why builders used asbestos

For many years, asbestos was one of the most commonly used materials in the Australian construction industry. Australia had the highest per capita use in the world from the 1950s through to the 1980s.

Between World War II and 1954, builders constructed 70,000 new homes in New South Wales using asbestos cement, and you will find the material throughout the country. Indeed, experts estimate that 98 percent of Australian homes built before 1976 contained some asbestos products.

Builders favoured asbestos because it was cheap, durable and had natural insulating properties. Construction companies commonly used asbestos for flat, patterned and corrugated wall and roof sheeting, roof guttering and brick cladding on homes and garages.

Health risks from asbestos

Builders stopped using asbestos in the 1980s, after doctors discovered that the material could cause serious health conditions. People exposed to asbestos fibres (during construction or around asbestos buildings) can inhale tiny particles. These particles can then cause several life-threatening conditions, including:

• Mesothelioma (cancer of the lining of the lungs)
• Lung cancer
• Asbestosis (scarring of the lungs)
• Pleural thickening (a problem where the lung lining thickens and swells)

These illnesses are deadly. To make matters worse, doctors cannot normally detect the symptoms of these diseases until the condition is at an advanced stage. As a result of these risks, Australia finally banned asbestos in construction in 2003. That aside, anybody who wants to renovate an older building (including garages, sheds and outhouses) must carefully consider the risks of asbestos.

Spotting asbestos products

It's not always easy to tell if part of your home has asbestos in it with a visual inspection. If builders installed your existing garage before 1980, it's likely that they may have used asbestos materials. These materials pose no risk if you leave them intact. It is only during removal when the risk increases, as you may release the particles and fibres.

Residential homes generally used one of two types of asbestos. Non-friable/bonded asbestos materials contain the mineral mixed in with cement, and the asbestos content can range from 10 to 40 percent. Loosely bound asbestos is not commonly found in residential properties. Builders normally used this material for insulation and fireproofing in commercial buildings. The asbestos content is much higher (up to 100 percent) and loosely bound asbestos is more dangerous.

It's quite likely that a builder used non-friable asbestos in a pre-1980 garage roof. Check some of the brand names that builders used in this period, all of which contained asbestos. Ultimately, you cannot confirm that your roof has asbestos in it without a laboratory test. If you're uncertain, you should contact a specialist company for more advice.

Removing non-friable asbestos

If you need to remove more than ten square metres of asbestos, you need to get a special licence from the local authority. For smaller quantities of non-friable asbestos, you can do the work yourself, but you must still carry out the work according to the Code of Practice for Safe Removal of Asbestos. Things to consider include:

• You cannot work with asbestos at heights without a licence 
• You need to make sure the work area and people working on the asbestos don't get too hot
• You must use wet and dry methods to minimise the risk of releasing particles
• You can't use tools that create dust (including brooms and brushes)
• You must use personal protective equipment

Safe asbestos removal isn't easy, particularly when you are getting rid of a roof. The height sometimes increases the risk that you may drop the material, and you will often need to work in an enclosed space. It's also difficult to avoid contaminating nearby areas. For example, you may need your neighbour's permission and help if you have adjoining garages.

You'll also need to safely dispose of the asbestos. You can't just take asbestos to a landfill site. Only certain sites have the facilities to deal with the material. As such, most people hire a specialist company to get rid of the material. 

Leaving the roof intact

Some homeowners decide to leave an asbestos roof intact. If the roof is watertight and in good condition, it's often easier to leave the garage alone. Indeed, you can drink rainwater safely off an asbestos roof. That aside, a damaged roof may pose health risks, particularly where you can see loose particles from the roof material

Getting rid of an asbestos garage roof is seldom easy. Asbestos poses a serious risk to human health, so it's important to think carefully about how to renovate this part of your home.