The Australian construction industry started to use asbestos materials in the 1920s, and homes built up until 1990 often include asbestos. When scientists discovered the link between asbestos and several life-threatening diseases, the government eventually banned the material in residential properties, but renovators must now deal with the legacy of this dangerous substance across Australia. Learn more about asbestos roofing, and find out what you need to do if you want to replace this material with something safer.
About bonded asbestos
You'll find bonded asbestos in many Australian homes. Manufacturers once mixed bonding materials like cement with asbestos to create products that they could easily make into sheets. Other common names for bonded asbestos include fibro, non-friable asbestos, asbestos sheeting and AC sheeting.
Homebuilders commonly used bonded asbestos for roofing. Asbestos roofs can include large sections of AC sheeting or multiple asbestos shingles. Guttering, gables, eaves and water pipes in homes built before 1990 are also more likely to have asbestos in them.
Bonded asbestos products don't generally include more than 10 to 15 percent asbestos. When asbestos products are in good condition, they don't pose a high risk to health because the asbestos fibres can't easily get into the air. If these products start to weather or become damaged they may start to release asbestos fibres. In this state, bonded asbestos can become dangerous.
Spotting an asbestos roof
You cannot accurately tell if you have an asbestos roof just by looking at it. For absolute certainty, you should contact an asbestos removal company and ask them to test the roof material. That aside, this process is often time-consuming and expensive, so it's useful to look for obvious signs of asbestos.
These signs include:
- Corrugated roof sheeting that is not made from tin or aluminium. This material will nearly always have asbestos in it.
- A material that resembles compressed cardboard. This roofing will also often have indents on both sides.
- Asbestos markings. Some later products carried a message to tell consumers about the asbestos content.
- Known brands. Some websites give you information about brands that contained asbestos, and the dates the manufacturers phased out these dangerous products.
If you are uncertain if you have an asbestos roof, you should always assume that you are working with the dangerous material. If you follow all the relevant safety precautions, you will protect yourself (and anyone else working on the roof) from asbestos exposure.
Who the law permits to remove an asbestos roof
If an asbestos roof is in good condition, it's often easier to leave the area alone. That aside, over time, the surface is likely to weather and deteriorate, and you will eventually need to replace the material. In the meantime, you should consider a roof sealant that can help bond the asbestos fibres together. Avoid cleaning the roof too vigorously before you apply the sealant, as you may release dangerous fibres.
Under Australian law, you can remove an asbestos roof without specialist help as long as you are only dealing with non-friable (bonded) asbestos. Even then, you must follow all legal precautions, and you can only do the work yourself if the amount of asbestos is low. You cannot remove asbestos from an area that exceeds ten square metres, and you cannot do the work if it will take longer than one hour in any seven-day period.
In many cases, these restrictions will stop home renovators dealing with asbestos roofs without professional help.
Removing asbestos yourself
Asbestos roofing often becomes brittle with age, so you need to consider how you will get access to the area. For example, you should never walk on asbestos surfaces. Other safe working practices that will cut the risk of harmful asbestos exposure while you remove the roof include:
- Avoid working in windy weather
- Close all windows and doors to the house
- Don't break up the sheets into smaller pieces
- Don't drop sheets to the floor from a height
- Do not slide the roof sheets across other sheets
- Spray the asbestos roof with diluted PVA glue and allow the material to dry before removing
Research safe asbestos removal practices before starting work to make sure you conform to legal safety requirements. If you aren't comfortable dealing with the asbestos on your own, contact a re-roofing professional.
Builders no longer use asbestos in Australian homes, but many properties still have asbestos roofs. If you want to replace your roof, carefully consider the risks that asbestos can present, and take the right precautions to avoid harmful exposure to this dangerous material.