How to cut asbestos cement
Since asbestos dust is a dangerous carcinogen, cutting asbestos cement should be avoided wherever possible. If you have no other choice, avoid using power tools of any kind and wear a respirator equipped with a high-efficiency particulate air (HEPA) filter when doing so.
Soak the material thoroughly, and then keep a running hose on the area during the cut. Vacuum thoroughly with a wet/dry shop vacuum equipped with a HEPA filter after finishing.
Mark the line to be cut on asbestos cement sheeting, using a pencil and straightedge.
Wet the line down and score a deep groove into the surface with a sharp utility knife and straightedge.
Place the sheet on a solid surface, such as a work bench or a table, with the score lined up with the side and the waste protruding over the edge. Place a thick plank on the cut line and clamp it to the table with a pair of C clamps. Apply sudden forceful downward pressure to snap the sheet.
Cut asbestos cement corrugated roofing material with a pair of heavy dolphin-nosed tin snips. Mark the cut line with a pencil and straightedge. Wet the surface down and use the tin snips to cut and break off small sections at a time. Smooth off jagged edges with a sharp carpenter's rasp to keep asbestos particle sizes as large as possible. Have a helper wet the area down while you're using the rasp.
Saw through a cut line in asbestos cement pipe with a hacksaw fitted with a coarse blade. Use slow deliberate strokes with the saw under water trickling from a hose pipe.
Cut a 45 degree bevel onto the edge joint of asbestos cement siding with a large carpenter's rasp. Have a helper move a running hose to follow the rasp while cutting. Use slow deliberate strokes to keep dust down.
Make roofing bolt holes in corrugated asbestos sheeting by punching holes out rather than drilling. Mark the holes to be punched out with a pencil. Use a bench grinder to shape the end of a short piece of 1-inch-diameter steel pipe to fit the profile of the corrugations; this will act as a support for the punch.
Clamp the pipe in a vice and have an assistant help manoeuvre the sheet into position over the pipe. Wet the surface down and place a punch over the premarked point. Deliver a sharp blow to the end of the punch with a hammer.
Drill smooth holes through asbestos cement with a hand drill fitted with a sharp drill bit if punching is impractical. Keep the area wet with a low pressure hose while drilling and crank the drill slowly. This method will reduce dust and keep the shavings as large as possible.
- Wear disposable paper overalls when cutting asbestos cement. Discard used overalls in a sealed plastic bag after use.
- Take a shower after work and shampoo your hair to get rid of dust particles.
- Use a respirator fitted with a HEPA filter, eye protection and heavy work gloves when working with asbestos cement.