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In the 20th century, asbestos sheets were the solution to all builders for simple sliding and roofing projects. While they were less costly to manufacture or buy, their hidden cost emerged years later in the form of illnesses. Why did builders choose asbestos for construction?
• It is durable
• It is a suitable fire resistor
• It is an excellent chemical resistor
• It is malleable
• It can resist harsh weather conditions
• It is a convenient heat resistor
• It provides strength when mixed with other materials
• It has excellent insulation properties
Before the world knew of its harmful nature, asbestos was so abused to the extent that it will take decades to completely rid the world of it.
What is Asbestos?
Asbestos is a naturally occurring mineral product that is resistant to thermal and chemical degradation. There are two types of asbestos: serpentine (white asbestos) and amphiboles (brown asbestos).
The amphiboles are further categorised into three types; anthophyllite, tremolite, and actinolite. The three subcategories are not used commercially; therefore, they are rarely mined. Amphiboles are unsafe, unlike serpentine, because of their formation and shape. With that said, it would be best if you treated all asbestos with caution and ensure that all protocols are followed when handling them.
Examples of building materials that contain asbestos are:
• Roof tiles
• Asbestos cement
• Floor tiles
• Ceiling tiles
• Textured coating
• Insulating boards
• Loose insulation
• Fire blankets
• Sprayed coatings
• Pipe lagging
• Rainwater structures
• Window sills
• Sink pads
• Electrical panels
Uses of Asbestos Cement Sheets
Asbestos cement products make up around 90% of asbestos production. The majority of which make asbestos roofing sheets. In Australia alone, they were manufactured in the 1920s and used in construction up to around the 1980s. You could be wondering if your home has asbestos. Well, most houses built before 1990 are likely to have asbestos cement sheets.
How to Identify Asbestos Sheeting
All cement-based products contained asbestos to improve the durability and strength of the material. Due to this, they were used widely in sheeting for roofs. Over time, they may have been replaced with asbestos-free materials, but you can never compare the quality. If they look weathered and old, chances are they contain asbestos.
You can identify asbestos sheeting by determining when the sheeting was installed and whether or not it was replaced. Having an asbestos test can give you conclusive results on whether the sheeting has asbestos.
Types of Asbestos Cement Sheets
Asbestos cement sheets are durable, heat-insulating, and weatherproof. All the qualities mentioned above are ideal for construction materials.
Corrugated Asbestos Sheets
Corrugated asbestos sheets were mainly used in attic roofs, furnace curtains, and agricultural buildings. Fibrous cement was affordable and created an alternative for metal panels that rust over time.
Asbestos Flat Sheets
Since drywalls are not as water-resistant as fibrous cement, fibrous cement was preferred in building underlayment for flooring and walls and in businesses and homes.
These are also known as asbestos millboards or cement wallboards. They were produced in sheets and used as fireproofing around wood stoves, heaters, and boilers, as well as washers and gaskets in electrical appliances.
Painting Asbestos Sheets
Can you paint your asbestos sheet? Yes, you can. However, it would help if you took great care not to loosen any fibres or dust. In fact, by painting the asbestos sheet, you keep it safer by sealing the surface. Additionally, use quality paint to avoid repainting often.
Safety Measures when Repainting Asbestos Cement Sheets
When painting your asbestos sheets, you should minimise the risks of releasing harmful fibres. To protect yourself and those around you, there are some rules you should follow:
• Make sure the sheets are in good condition. If the surface is broken, consult the experts.
• If the surface is dirty, do not scrape, sand, wire brush, or power wash it.
• Loose dirt and moss should be wiped with water and left to dry.
• Use a low-pressure spray to apply the paint.
• Avoid working in high places without a ladder.
• After the first paint, you can repaint if need be.
Asbestos Cement Sheet Removal
If the asbestos sheet is not in good condition (if the fibres are exposed), the best course of action would be to remove the sheet and replace it with a modern roofing solution.
In cases where there is no damage to the sheets, the best solution will be to clad the roof. By doing this, you contain the asbestos cement, therefore, curbing any internal and external threats while offering a cost-effective solution.
Safety Precautions when Removing Asbestos Sheets
The following advice only applies to asbestos cement sheets and not to asbestos materials as they are more dangerous:
• Try to remove the sheets as a whole and avoid breaking them.
• Dampen the sheets before you start removing them.
• Never use hand saws or power tools when removing the asbestos sheets.
• Always hand down the sheets to someone else instead of dropping them.
• Wear P3 dust masks at all times during the asbestos removal process.
• Wear hooded disposable overalls and rubber boots.
• Ensure your ladder is in good condition to avoid accidents.
Removal and Disposal of Asbestos Roof Sheeting
The following is a detailed procedure on how to safely remove and dispose of asbestos roof sheeting:
Step 1: Ensure that the area is free from any danger, and you can easily access the site. It will allow ease of movement when cleaning.
Step 2: Remove any item that can trap dust, such as carpets, furniture, light fittings and curtains. Sweep the room to reduce dust.
Step 3: Seal the room with duct tape and a plastic sheet to prevent dust from going to other rooms in your house.
Step 4: Place trestles, ladders or scaffolds that you will need to access the roof and sheet fixings in the room.
Step 5: Place the crawling boards in place as asbestos is brittle and accidents are common.
Step 6: Choose a safe and secure place away from the house that you will store the asbestos sheets.
Step 7: At this stage, make a thorough inspection of the site to ensure that everything is ready for the work to start.
Step 8: Make sure that all workers are in full PPE gear before they start their designated duty. During the work, the supervisor should also check for compliance.
Step 9: Spray the roofing sheet with water and keep it damp to reduce dust. If the weather is hot, keep spraying the roof at regular intervals.
Step 10: The roof sheeting should be unscrewed or cut off with bolt cutters to avoid producing dust when it breaks.
Step 11: Carry the sheets and lower them to the ground carefully. Workers should not carry more than 20kgs. You should get help from another person to hold the sheets.
Step 12: Double wrap the sheets and seal them. Fix a warning label between the layers.
Step 13: Stack all the sheets together and count them to make sure you have stored all of them there.
Step 14: After removing all the sheets, clean the exposed room and site, paying attention to beams, rafters, wall pledges and any other area where dust is trapped.
Step 15: Use a Type H vacuum cleaner to avoid creating dust.
Step 16: Once your room and the whole site is clean, inspect it, then remove the seals.
Step 17: Empty the vacuum cleaner and seal all debris in bags.
Step 18: Transport the sealed bags of debris and asbestos waste to a landfill site. Account for all sheets and debris.
Step 19: All the workers should remove all PPEs and seal them in a bag, then place them with the asbestos waste to be buried.
Step 20: Keep a copy of the weigh-bridge note as proof of delivery to the landfill.
Diseases Caused by Asbestos Cement Sheets
Working with asbestos cement sheets can expose you to many health risks. The workers involved in the manufacturing process endure the highest level of asbestos exposure. The good properties of asbestos that make it suitable for construction materials are hazardous to human health. Even though asbestos was banned in Australia, people still die of asbestos-related diseases. Why?
• One reason is that the symptoms of asbestos exposure may take decades to develop. Asbestos-related diseases are slow and painful. Those suffering were probably exposed in the 80s or 90s.
• The other reason is that people are still exposed. Many seemingly safe buildings can have products containing asbestos. However, you cannot know by looking at them as asbestos fibres are tiny and cannot be seen as you inhale them.
Such exposure to asbestos can cause several asbestos-related diseases such as:
• Lung cancer
• Ovarian cancer
• Benign pleural plaques and pleuritis
• Laryngeal cancer
• Pharyngeal cancer
• Stomach cancer
• Colorectal cancer
People who have worked with asbestos should monitor their health for signs such as abdominal distension or difficulty in breathing. If you are diagnosed with an asbestos-related disease, you should seek a specialist's opinion. Who is at a high risk of exposure from asbestos sheets?
• Demolition crews
• Construction workers
• Military personnel
• Factory workers involved in the manufacturing of asbestos sheets
• DIY renovators
Compensation for Asbestos-Related Diseases
If you are diagnosed with an asbestos-related disease, you are eligible for compensation from the product's manufacturing company. After all, the manufacturer was aware of its harm to people but still chose to use asbestos. What compensation can the manufacturers pay you?
• The wages you lose from an asbestos-related disease.
• Treatment for the disease.
• Anything else they agree on.
The Future of Asbestos
Asbestos is still an essential part of the manufacturing of products. Although it was banned entirely in Australia in 2003, there are limited exceptions where permission is granted to import or export goods containing asbestos. These strict asbestos regulations put in place are expected to eradicate health problems related to asbestos.
For instance, you have to ensure that all your imports or exports do not contain asbestos before they arrive or leave Australia, regardless of whether your client has indicated that the goods are free from asbestos. The Australian Border Force is mandated by Australian law to regulate all importation and exportation of goods at the border.