A particular type of non-wood siding product popular from about 1940 to 1960 made use of asbestos fibers blended with cement to create hard panels that were both strong and fireproof. Though sometimes known simply as "asbestos siding," these products are more accurately described as "asbestos-cement." By the early 1960s, as it became clear that asbestos fibers posed health risks when inhaled or ingested, the use of asbestos in siding and other building products was gradually phased out and other types of fibers were used to reinforce cementitious siding products. But millions of homes were sided with this siding containing asbestos during these years, and today's homeowners and siding companies are faced with the problem of how to handle this hazardous material as homes are updated with new siding.
You might think that asbestos-cement siding must be removed, but in fact, removal may be unnecessary. Asbestos siding never needs to be removed simply because it is asbestos. As long as the siding remains intact, it can stay in place, where it remains harmless. Asbestos is really only an issue when it is disturbed in a manner that frees the asbestos fibers to travel through the air or into soil or water supplies. In fact, you may be able to install new siding on top of the asbestos-cement siding without removing it at all. This is often the approach used by siding replacement companies who may install new vinyl siding or other appropriate materials directly over asbestos-impregnated siding, thereby safely sealing and confining it.
However, if the old siding material is flaking, cracking, sloughing, or otherwise badly damaged, then removal is usually warranted. You have two options: You can either hire an asbestos abatement company (or a siding company that works in partnership with abatement specialists) or you can do it yourself.
Before You Begin
In many municipalities, there are no laws requiring that you hire an asbestos company. Laws on the books often pertain to the disposal, not removal, of asbestos siding. Removing asbestos siding, then, can be a do-it-yourself project, though you need to make sure that you do the job safely and completely. If you are not cutting, sanding, drilling, or otherwise creating dust from the siding, the hazards are greatly reduced. Merely removing a nail and taking down a siding shingle usually will not place you in danger.
There are many types of cementitious siding products, so before you worry about special removal and disposal techniques, you need to determine if you indeed have siding that's impregnated with asbestos fibers. Some likely signals that you are dealing with potentially hazardous siding include:
- A hard-surfaced (non-wood) siding shingle installed before 1979 is likely to include asbestos. After this point, most cementitious sidings made use of other types of fiber.
- Siding planks or shingles containing asbestos often have grooves or a faux wood grain pressed into them. The bottom of the shingle often has a wavy pattern.
- If you can remove a single panel, the backside of an asbestos-siding product generally does not have a manufacturing code stamped onto it. If this stamp is present, you are probably looking at a non-asbestos product.
- Most asbestos-containing siding products are 12 x 24-inch shingles, similar in size to roofing shakes and shingles.
Even though you are removing the siding yourself, the costs you incur might surprise you. You will likely need to buy a proper HEPA respirator, disposable hazards suits, extra-strength disposal bags, and possibly some other demolition tools. The most expensive components, however, might be the work permits and disposal fees. This can vary quite a lot by region, but in urban areas, the permitting and hazardous waste disposal fees might well cost several hundred dollars. But this will probably still be many thousands less than the cost of having the work done by a professional remediation company.
There is no need to panic merely because you identify your siding as a product that contains asbestos. Asbestos siding products made by blending fibers with Portland cement are among the most stable (non-friable) of all building materials containing asbestos, especially when compared to the insulation materials that contain asbestos. The asbestos in siding materials is bound together very tightly with hardened cement, The primary danger posed by asbestos comes when tiny fibers become airborne where they can be inhaled into the lungs. Unless siding materials are shattered, drilled, sanded, or weathered so badly that the surfaces have begun to fray and splinter, you are probably not in any danger simply because this type of siding covers your home.
But you will need to take some special precautions if you choose to remove asbestos-cement siding yourself. The process of pulling nails and prying off siding shingles will inevitably cause some breakage, and it's important to do this work carefully so as to avoid directly inhaling fibers or dust, or distributing asbestos fibers around where they can create an ongoing hazard.
The potential health problems caused by asbestos are very real, including asbestosis, pleural disease, lung cancer, and mesothelioma. Just as important as your demolition technique is the process you use to dispose of the asbestos-impregnated siding materials. Asbestos removal requires that you apply for a permit to do the work, and the local permits office will give you specific requirements for how to bag up the demolition materials and where to dispose of them. Under no circumstances should you violate these requirements, as asbestos discarded improperly in standard landfills can cause contamination to water supplies.
Asbestos-laden debris is usually handled by recycling companies who transform the materials through heat treatment materials into safe ceramics or aggregates used in road construction. Any other method of disposal is probably illegal. NEVER try to dispose of these materials at standard landfill sites.
Equipment / Tools
- Safety goggles
- A pry bar for lifting nails
- A nail puller or nail-head cutter
- Utility knife or scissors
- HEPA purple color-coded respirator
- Debris containers
- Garden hose with a water source and spray nozzle
- Spray bottle or garden pump sprayer
- Ladders (as needed)
- 6-mil polyethylene plastic sheeting
- Disposable paper coveralls, rubber boots and rubber gloves
- Asbestos waste disposal bags and duct tape
- Liquid dishwashing detergent
Obtain a Permit
Apply for an asbestos removal permit. Your local building permit office may issue these. Or, they can direct you to the agency that does. Without a doubt, your area will require a permit of some type.
The cost of the permit may be based on an estimate of the volume of debris your removal will generate. It may range from less than $50 to several hundred dollars depending on where you live and the nature of your removal project. The permitting process may also involve notification to the state department of health.
Prepare the Site
Post signs warning any “drop-in” friends, family, and other visitors, of the work taking place. Lay a 6-foot-wide strip of 6-mil sheet plastic along the side of the house where removal is to occur. Try to work in the shade so the wet siding will remain wet. Create an entrance/exit “transition” zone to the work area by laying down an additional 6 x 6-foot piece of sheet plastic in a convenient location next to the plastic strip along the wall. Keep a plastic disposal bag at this location.
Suit up with your disposable coveralls. Also put on gloves, goggles, boots, and respirators equipped with HEPA filters.
Keep the Asbestos-Cement Siding Wet
Hose down about 10 square feet of siding. Mix approximately 1 teaspoon of liquid dish-washing detergent with water in the pint-size spray bottle or about one-half cup of detergent in a garden pump sprayer. As you work, spray down the siding with this solution to keep dust from becoming airborne.
Start Siding Removal
Remove pieces of siding by pulling nails or cutting nail heads so as to minimize breakage. If necessary, carefully lift siding pieces with a pry tool to expose nail heads. If siding should begin to crack or crumble, immediately wet the cracked or broken areas with the pint-size spray bottle or garden pump sprayer. Breakage can potentially release asbestos fibers. Wet the back of each piece of siding as it is removed. Lower removed siding to the ground. Do not throw or drop it. Keep all debris on the plastic strip and keep on wetting it.
Remove Siding Pieces
Load wet debris and other contaminated materials into sturdy containers, such as cardboard boxes or burlap sacks. If cardboard boxes are used, line each box with 6-mil polyethylene and leave enough excess plastic to cover the debris and seal the plastic-covered debris with duct tape. Boxes should then be wrapped in one or more layers of 6-mil plastic or inserted into a single pre-marked asbestos waste disposal bag.
Double-Bag the Asbestos
Double bag or wrap filled containers in pre-marked 6-mil asbestos waste disposal bags. Twist the top of each filled bag, bend the twisted part in half, and seal it with duct tape. If containers are to be wrapped rather than bagged, use 6-mil polyethylene plastic and ensure all seams are sealed with duct tape. Affix an asbestos warning label to each sealed package.
Clean the Work Area
Re-wet any debris on the strip of plastic next to the wall. While continuing to stand on the plastic strip next to the wall where the removal is being done, double bag or wrap all debris as described above. Then wrap or roll up the strip of plastic along the wall, working your way back to the entrance/exit “transition zone” strip of plastic. Step onto the transition zone plastic and double bag or wrap the last of the strip plastic.
While standing on this last piece of plastic sheeting, spray yourself (or each other) with water to wet down any asbestos debris/fibers on the outside of your respirator and disposable coveralls.
Remove boots. Then remove your disposable gloves and coveralls by peeling them off and turning them inside out as you remove them. Leave these contaminated items on the transition zone plastic for disposal. Step off the last plastic sheet.
Take off respirators and remove their filters for disposal. Then wash off and wipe down the tools used in removal, along with your respirators, goggles, and boots. Move each item off the plastic as it is cleaned.
Remove Debris From Area
Double bag remaining debris, transition zone plastic, and disposable items in properly labeled asbestos disposal bags or double wrap them in 6-mil plastic sheets. Seal each bag or package tightly with duct tape. Use wet rags for any further clean-up. Take a shower to rinse off any stray fibers that might still be clinging to you.
Asbestos debris from an asbestos project must be disposed of at disposal sites or transfer stations licensed to receive such waste. You will probably be charged a fee to handle this material.
All debris must be sealed in two layers of 6-mil polyethylene plastic. Remember, siding pieces have sharp edges that can perforate this plastic material unless the siding is first loaded into sturdy containers. Packaged debris in punctured plastic will not be accepted by waste disposal sites. You must write your last name, address, and date of removal on each container. Check with the disposal site for any additional requirements.
Never attempt to vacuum or sweep up asbestos debris. This will cause any fibers present to become airborne.
When to Hire a Professional
The process for removing asbestos-cement siding is not technically difficult. But because the mineral asbestos fibers can be dangerous when airborne, removing this type of siding requires some special handling techniques—a process overseen by government regulation. In most communities, homeowners are entirely allowed to do this work themselves, but for many people the mere thought of handling potentially carcinogenic materials makes it very attractive to hire a professional abatement company to do this work.
If you want to remove asbestos siding with the help of a company, it will be expensive because that one word—asbestos—changes the rules dramatically. No longer are you merely hiring a general contractor who strips the siding and tosses it in a roll-off container. Now you'll also be paying for a regulated specialty contractor who needs to meet state licensing requirements. Among other requirements, asbestos abatement company workers suit up, wear respirators, shield the area, and use liberal amounts of water to hold down the dust.
Professional remediation costs for asbestos-cement siding is usually based on the square footage of the wall areas to be removed. One national contractor networking service lists the national average for asbestos-cement siding remediation at $8 per square foot. This means that even a small house can easily cost several thousand dollars to have the siding safely removed.
You can find a list by searching for certified asbestos removal companies," and then narrowing it down to a local county, city, or state website (often designated with a .gov domain suffix).
Another option is to hire a siding replacement company that is familiar with collaborating with abatement specialists. In this way, you can coordinate with a single general contractor who will work with the abatement specialist as a subcontractor. But be prepared for a bigger project cost, as the siding contractor will certainly pass along the abatement costs to you.
The Encapsulation Option
Because asbestos-cement siding is a relatively stable building material—and because professional removal is so expensive—the better option is often to encapsulate it. This can be done by simply installing the new siding material, such as vinyl lap siding over the old siding—a job that should be performed by an installation team familiar with working around asbestos. Another form of incapsulation involves a professional team coating your siding with a latex masonry primer followed by a high-quality latex paint that will prevent the release of asbestos fibers. This form of encapsulation costs from $2 to $6 per square foot.
Asbestos Laws and Regulations. U.S. Environmental Protection Agency.
Asbestos - Hazards. U.S. Department of Labor, Occupational Safety and Health Administration.
Asbestos Cement Siding or Asbestos Cement Shingles. Inspectopedia
Health Effects of Asbestos. Agency for Toxic Substances and Disease Registry, Division of CDC.
Job-Site Controls for Work Involving Asbestos-Containing Material (ACM). U.S. Environmental Protection Agency.
Asbestos - Hazards. U.S. Department of Labor
How Much Does Asbestos Siding Removal Cost? The Asbestos Institute