Asbestos is a form of silicate with fibres that can be breathed into the lungs.
Decades later, people can become sick and die. Asbestos causes some horrendous lung diseases: lung cancer, mesothelioma and asbestosis. The first wave of deaths from asbestos occurred among the people who were the miners, trans-shippers, manufacturers, and builders who did not take precautions to protect themselves. There is now a new round with people who have been involved in its demolition and removal.
In the 1950s, asbestos was seen as a miracle ingredient, due to its strength, durability and fireproof nature and was added to many building products. Generally, in New Zealand houses, 5 to 15% of white asbestos, Chrysotile, was added to the sand and cement as reinforcement to give additional tensile strength, similar to rebar in concrete.
A James Hardie factory opened in Auckland in 1938 to manufacture sheet wall linings and water pipes. A second plant owned by Fletchers operated in Christchurch from 1943 to 1974 to produce building materials. The James Hardie plant stopped production of sheet products in 1983, but continued using asbestos in pipes until 1987.
Asbestos isn’t as immense an issue in New Zealand as it is in, say, Australia or the United States of America, where asbestos-based products were commonly used in the sheet lining of kitchens and laundries, or in insulating heating pipes in those countries. Here in New Zealand, houses built in a similar period generally used Masonite, which is a product essentially consisting of pine sawdust, bonded using only heat and pressure. We do not have many domestic furnaces used commonly in the colder parts of the USA. Asbestos was not generally used in bulk household wall or ceiling insulation.
But it is possible that New Zealand houses built before 1988 may contain some asbestos-based building products.
Common asbestos examples in New Zealand:
Fibrolite was used as wall or eaves lining. This is fibre cement sheeting with asbestos as the binding fibre that was used in residential construction until around 1988. In the early years, it was mostly used for eaves lining, or the sheet cladding to garages. Fibre cement has not contained asbestos since then. It contains the less durable cellulose from wood pulp instead. Fibrolite can be recognised as having a dimpled back surface. It looks like flyscreen mesh, rather than the smoother wavy rear surface of a cellulose-based product that replaced it.
Coverlite was a similar, slightly corrugated exterior wall lining. Often used in gable ends.
Super Six corrugated roofing was sometimes used on industrial buildings and rarely with homes.
Asbestos cement roof or wall shingles.
Textured or sprayed ceiling finishes such as Vermiculite may contain asbestos. It is best to treat as if it does until a sample can be tested by a laboratory.
Vinyl floor tiles and their underlay, installed prior to about 1990. These tiles are a danger to strip, particularly if subsequently sanding the floor, where the fibres are released to the air.
Fusebox backing boards, etc.
Any asbestos should be removed in full accordance with WorkSafe NZ (Health and Safety at Work (Asbestos) Regulations 2016)
Using full-face masks and disposable protective clothing.
Soaking the affected area in soapy water to reduce fibre release, avoiding fragmentation of the material.
Extracting fixings cleanly so the panels remain intact and unbroken.
Double bagging all material, ie, in two layers of 200 µm thick polythene sheet with pressure-sensitive taped joints.
Disposal in approved landfill areas.
The good news is that asbestos is actually relatively stable, and can remain inert for many years, particularly if covered in paint. Just avoid drilling, sanding or otherwise releasing the fibres into the atmosphere. Any health issues arise only when the asbestos-containing product is disturbed.
Homeowners are legally permitted to remove up to ten square metres of intact sheet asbestos on their own property using strict safety precautions. Anything larger, or any damaged or crumbling asbestos, must legally be handled by a licensed removal specialist under WorkSafe NZ regulations.