How to identify asbestos in your home.

Here I talk about how to identify asbestos.  You will need to be able to do this if you have a house that was built prior to or around 1980, then there is a good chance that somewhere in the building there will be products that contain asbestos.  So how to identify asbestos? 

The only sure way to identify asbestos.

The only positive way to detect the presence of asbestos in a product or substance is inspection by a trained technician using a scientific microscope

Contact a licenced asbestos removalist in your area and have samples of the material tested at a registered testing laboratory.
For commercial properties have a full asbestos audit done on the property which includes labs tests of all suspect materials.

A visual inspection, sometimes may identify asbestos if you know what to look for.

Assuming that the house is in the right age group, 1920's to 1990's then a visual inspection alone may help a prospective purchaser or intending renovator to decide that the house has asbestos problems.  As stated above there is only one sure way, by lab tests, to truly determine that it does not have asbestos problems.  However unless the house purchase is about to go ahead, nobody wants to spend a lot of money on expensive tests, so below are a few pointers that may help you to identify asbestos containing products in a property.
  • A couple of light raps with the end of say a screwdriver and the sound it makes usually can tell you if you are looking at painted drywall, Masonite, solid masonry plastered, or some sort of cement based sheets.  If this doesn't help, scratch or poke it with the tip of a fine screwdriver. AC sheets are hard, brittle and sound drummy, not solid when rapped.
  • Any smooth sort of sheeting, inside and out, on the walls, ceilings and as lining under the eaves that has the the 8mm thick batten covering the joints is immediately suspicious.  Add to these the use of the moulded "L" shaped external corner moulding and you can be fairly sure that you have identified asbestos cement sheeting.  The presence of shear point nails will also confirm suspicions.
  • Because AC siding is brittle compared to other more modern sheets it is common to see pieces chipped off near the edges of sheets. The cover battens are often split or broken off near the bottom or top right at the last nail.
  • As mention before, AC sheeting in the thinner sizes has a slight ripple effect on the face.  You may have to get your eye close and look along the surface to see it.
  • If there are any broken, non painted edges then sometimes it is possible to see small fibres exposed.
  • Brick houses are usually free of problems, but check any eaves lining which is where you are most likely to identify asbestos in these houses.
  • If you rap on what appears to be painted brickwork on a brick veneer home and it sounds drummy the look further, it could be the asbestos containing fake brickwork.
  • In an old Fibro clad house, if a previous owner has taken off the old AC cover battens and corner moulds, and bogged the joints up, and say put aluminium angles on the external corners it should be fairly easy to pick.  Given that we had 40mm wide cover battens to play with and that we used that fairly imprecise tool the Fibro cutter to cut the sheets then the joints between the sheets were less that perfect, and also, given the quality of the timber frames then some of the sheets were not level with their neighbors, making it almost imposable to mask the joints.  Attempts to cover it all up with texture paint also fails to cover the joints between sheets.
  • Harder to find, and sometimes impossible to see are the jobs where new cladding or new siding has been fixed on top of existing Fibro.  On high level houses it is sometimes possible to see the old material from underneath.

Check out my other pages in this series for photographs which will also help you to identify asbestos products with a visual inspection.

An old AC sheet or Fibro cutter
identify asbestos- My old Fibro cutter.

The Fibro cutter on the right was in effect just a pair of shears.  With a lot of care it was possible to get a reasonably straight cut but more often than not they left a fairly crude jagged edge.  As a result the cut edges were nothing like as straight and the joints less precise, than on later more modern sheets reinforced with cellulose fibres that replaced Fibro.  Fibro cutters hardly work on moderns sheets as they are not as brittle as the old asbestos sheets were.

Other more invasive methods that may identify asbestos containing products.

Once again, a word of caution, suitable precautions should be taken when removing even the smallest pieces 

  • For a few years before it was banned totally it was possible to identify asbestos products by the fact that they sometimes had a warning label or stamp on the back of the sheets saying that "this product contains asbestos"
  • Conversely you may see "this product does not contain asbestos" stamp on them.
  • So by gently prising off a suspect sheet you may be able to see one of these labels.
  • It has been said, though I have never tried it that if a cigarette lighter is applied to a broken edge of AC sheet with fibres exposed then these fibres will not burn, whereas the fibres in other similar looking material will burn.  Hardly scientific.

There are now on the market Asbestos Testing Kits of various types.  Basically what happens is that the company sends you a kit with instructions of how to safely take a couple of samples.  These samples are then sent back to the company and their approved testing laboratory test them and you get your result back in a couple of weeks.

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Asbestos - Disclaimer.

This is a highly complex and stringently regulated field.   I am not a scientist, I am not a government spokesperson or anyone with any authority to talk or give professional advice on the subject in your area.

What I am is a retired builder with a large amount of practical experience fixing fibrous asbestos cement products and then later removing them.

In 1995 I was issued an asbestos removal licence (43133) by the Northern Territory Work Health Authority, and did many asbestos removal jobs, complying with Australian Work Health (OH&S) Regulations and the NOHSC National Code Of Practice For The Safe Removal Of Asbestos.

I hope you get something of value out of these pages, but a word of caution, at the last count I get visitors from 132 different countries, there is no way that I can give specific advice that would comply with the regulations in your country, state, district or local area.

In other words, the onus is on YOU to check out the regulations where you live, and comply with them.   If you have any doubts get advice from a licensed person IN YOUR AREA.



Please Note! The information on this site is offered as a guide only!  When we are talking about areas where building regulations or safety regulations could exist,the information here could be wrong for your area.  It could be out of date!  Regulations breed faster than rabbits!
You must check your own local conditions.
Copyright © Bill Bradley 2007-2012. All rights reserved.
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