There are no risks associated with pressed metal roof tiles containing asbestos if they remain in good condition and are left undisturbed.
Asbestos roof tiles nz.
Chrysotile asbestos is the type usually present in asbestos containing materials in new zealand houses.
You will find that existing asbestos roofs have probably been in place for many years and in the case of the new zealand naval dockyards the material had weathered and protected their facilities for close on 65 years right on the coast in the most severe environment with no corrosion or breakdown of the substrate.
That s not surprising as asbestos has so far been identified in around 3800 different building products used in new zealand homes and commercial buildings from lino flooring to roofing tiles to.
Mastic or bitumen was the most common material used to adhere the stone chip to the pressed metal at that time.
Examples of asbestos in homes.
Asbestos was used in vinyl wallpaper from the 1920s and in the vinyl floor tiles and sheet flooring that rose to prominence in the 1950s.
However a health risk arises when asbestos fibres become airborne and can be breathed into the lungs.
But other types of roof tiles containing asbestos also exist.
Review of the scientific evidence of non occupational risks.
Some roofing and siding shingles are made of asbestos cement.
Asbestos exposure in new zealand.
Decramastic tiles asbestos asbestos in early pressed metal stone coated roofing tiles prior to early 1980s some versions of mastic or bitumen based pressed metal roof tiles produced prior to the early 1980s contain asbestos.
Any asbestos cement roofing that shows evidence of damage such as broken roofing or noticeable surface weathering may need to be replaced.
They do not need to be removed solely because of the presence of asbestos.
Chrysotile fibres tend to break across the fibre so become shorter and remain thicker than the crocidolite and amosite fibres.
Asbestos cement materials will typically last about 50 60 years.
Asbestos is found in some vinyl floor tiles and linoleum and as backing on vinyl sheet flooring and adhesives.
All mastic or bitumen based pressed metal roof tiles should be suspected of containing asbestos.
However if the roof is in good condition it may not need to be disturbed so long as it is properly and regularly maintained.
Asbestos contaminated roof tiles are regularly arriving at new zealand scrap metal yards when they should be safely sent to landfills according to the scrap metal recycling association of new.
