During the height of its popularity from the 1920s through the 1980s, asbestos cement siding was used on millions of homes across America. This type of siding contains anywhere from 10 to 15 percent asbestos fibers mixed with Portland cement.
The most common forms of asbestos siding include:
- Shingles with a wavy, layered look
- Overlapping flat panels about 3 feet long and 6 inches wide
- Boards resembling wood clapboard siding
Asbestos siding was so prevalent because it had several desirable properties:
- Fire resistance – The asbestos fibers prevent the cement boards from melting and spreading flames. This improves fire safety.
- Durability – Properly sealed and painted asbestos siding holds up well to weather, moisture, and impact without rotting, warping, or denting. It can last 50 years or longer.
- Affordability – Asbestos cement products provided an inexpensive alternative to wood siding.
- Low maintenance – Unlike wood, asbestos siding doesn’t require regular repainting or staining. Its cement material provides natural weather resistance.
However, asbestos also poses well-known health risks when the fibers become airborne. Breathing in these microscopic particles can cause lung diseases like asbestosis, lung cancer, and mesothelioma.
That’s why it’s important to take precautions when dealing with asbestos siding during painting or removal. We’ll cover specific safety tips throughout this article.
Now let’s dive into the big question…
Should You Paint or Replace Asbestos Siding?
If your asbestos siding is still in good structural condition without any cracks, rot, or breakdown of the material, you may be able to simply paint over it instead of replacing it.
Here are some pros of painting over asbestos versus removing the siding:
It’s much more affordable. Asbestos abatement followed by new siding installation is extremely costly, often running over $10,000. Painting can refresh the look of your home for less than $2,000.
It doesn’t disturb the asbestos. Removing siding can release asbestos fibers into the air, creating a hazard. Painting encapsulates the panels so fibers can’t escape.
Paint adheres exceptionally well. The porous, textured surface of asbestos cement provides excellent adhesion for paint. It resists chipping and lasts a long time.
No need to dispose of hazardous waste. Asbestos siding must be disposed of at designated landfills. Painting allows you to avoid this headache.
However, if your siding is badly damaged with deteriorating cement, cracking, or missing sections, it may be time for replacement. Paint will not properly adhere to crumbling panels.
Replacement also allows you to increase energy efficiency. Asbestos has very low R-value insulation properties. New siding with added insulation can reduce heating and cooling costs.
In the end, inspect the current state of your asbestos cement boards to determine if painting is an option or if replacement is the better solution.
Assuming your siding just needs some cosmetic rejuvenation, read on to learn how to prep it for painting.
How to Properly Prepare Asbestos Siding for Painting
Painting asbestos siding isn’t much different from painting wood or vinyl. But there are some unique precautions to take during surface prep to keep asbestos fibers contained. Let’s look at the key steps:
1. Inspect for Existing Lead Paint
If your home was built prior to 1978, the asbestos siding likely has layers of lead-based paint on top from past repainting jobs. You’ll need to take precautions to avoid lead exposure when removing the old paint.
Start by using a lead testing kit or sending paint chip samples to a lab for analysis to confirm lead content.
Then thoroughly wet the siding and carefully scrape away all loose, flaking lead paint using hand scrapers, keeping the surface wet to minimize dust.
Be sure to wear safety goggles, gloves, and a respirator mask rated N95 or higher during this process. Dispose of paint debris properly at a hazardous waste facility.
Only remove paint to the lowest layer above the asbestos. Do not scrape down to the bare asbestos, as this risks releasing asbestos fibers.
2. Clean the Siding
Your asbestos siding needs to be free of dirt, mildew and chalky paint remnants before applying fresh paint.
Never use abrasive methods like power washing, dry scraping, or sanding, as these can damage the siding and release asbestos particles.
Instead, use a soft bristle brush and bucket of warm, soapy water to gently scrub the asbestos cement panels. Work in small sections, rinsing frequently before the soap dries.
If needed, apply a liquid siding cleaner formulated for asbestos and follow product directions.
Rinse thoroughly and allow the asbestos to fully dry for 2-3 days before painting. The surface needs to be clean and free of moisture that could prevent paint from properly adhering.
3. Address Any Cracks and Holes
Inspect the asbestos siding and use asbestos-rated caulk to seal any small cracks and openings. Larger holes and missing sections will need to be patched with new asbestos cement boards.
If the damage is extensive, replacement may be a better option than patching.
4. Wear Proper Safety Gear
Even with gentle cleaning methods, you’ll want to take precautions against asbestos exposure when prepping the siding:
- Disposable coveralls
- Rubber gloves
- N95 respirator mask
Work slowly and carefully. If you’re unsure about safely handling asbestos, it’s best to hire certified asbestos abatement professionals for the prep work.
Okay, once your siding is prepped, you’re ready to paint!
How to Safely Paint Asbestos Siding
With the surface ready, the actual painting process is straight forward. Here are some tips:
- Paint small sections at a time to avoid drips and runs. Work top to bottom.
- Use high quality primer rated for exterior cement board and masonry. This seals the surface.
- Apply two finish coats for complete coverage and protection.
- Use airless sprayers for the fastest, most consistent results. Adjust pressure to avoid damaging soft asbestos.
- Consider hiring a painting pro if you don’t have the proper respirators and protective gear. Professionals have specialized training for safely handling asbestos.
- Work slowly and cautiously. Do not scrape or sand the asbestos, and avoid excessive brushing or roller pressure.
- Follow manufacturer drying times between coats. 1-2 hours is typical for latex paints.
- Dispose of painting tools or wash thoroughly after use if also used for non-asbestos projects to prevent contamination.
And remember – you’ll need to take the same protective measures as when prepping the siding. Wear disposable coveralls, gloves, goggles, and an approved respirator when spray painting or brushing close to the asbestos.
Now let’s look at the best types of paint for asbestos siding.
Choosing the Right Exterior Paint for Asbestos
You don’t necessarily need special asbestos paint. But you do need paint formulated for exterior concrete and masonry surfaces. The best options are:
1. Encapsulant Paint
These specialty coatings are designed to seal in lead-based paints, and they also work well to encapsulate and protect asbestos cement boards.
The thick encapsulant paint prevents cracks and seals the surface so fibers cannot be released. Top it with a 100% acrylic latex paint for protection from the elements.
2. 100% Acrylic Latex Paint
A high-quality latex formulated for exterior concrete substrates will also adhere well to asbestos. The acrylic provides flexibility and protection against cracking.
Latex allows moisture to escape from the siding instead of trapping it like oil-based paints can. This prevents bubbling and peeling.
Be sure to use exterior grade paint. Interior latex won’t withstand sun, rain, temperature extremes and outdoor exposure.
3. Elastomeric Paint
If your asbestos siding is experiencing movement or cracking from temperature changes, an elastomeric paint can help cover hairline cracks while providing a flexible coating that resists chipping and peeling.
4. Avoid Oil-Based Paints
Oil-based paints don’t allow moisture to pass through the siding, which can cause paint failure. They become brittle over time. For asbestos, stick with high quality 100% acrylic latex paint.
Whatever product you choose, be sure to follow manufacturer instructions for proper surface prep, priming, application and drying times when painting asbestos siding.
And don’t forget your PPE!
Paint Color Recommendations for Asbestos Siding
When selecting a color for your asbestos panels, keep these tips in mind:
- Stick with light or bright colors to freshen things up. Bold dark hues can make the dated siding look even older.
- If your window and door trim is in good shape, choose a color that coordinates well with the existing trim.
- Take inspiration from other homes in your neighborhood. You want your color scheme to complement the overall aesthetics.
- Factor in your home’s architectural style. Certain classic colors like forest green suit a craftsman bungalow best.
- Neutral shades of gray, brown, tan, or white never go out of style. They blend into landscaping.
- Don’t be afraid to have some fun with color! Paint your entry door a bright complementary hue as an accent.
Pro tip: Use the existing paint color as a base coat before painting the finish color. This will provide better coverage on old asbestos cement boards.
Signs It’s Time to Replace Asbestos Siding
While paint can buy you many extra years, there comes a point when asbestos siding replacement provides a smarter long-term solution.
Here are signs your asbestos panels may need replacement instead of repainting:
- Visible cracks, crumbling sections, and missing pieces of siding
- Paint is no longer adhering to the asbestos surface
- Evidence of moss, mold, and moisture damage behind siding
- Storm damage that has disturbed the siding
- Planning extensive renovations that require removing siding
- Health concerns about aging, deteriorating asbestos material
- Desire for improved insulation and energy efficiency
Replacing asbestos siding can be expensive – most homeowners spend $10,000 to $25,000. But new fiber cement panels provide increased durability and insulation without asbestos risks.
Trust the Asbestos Siding Painting Pros
If all this asbestos talk has you nervous about DIY painting, don’t worry! Professional painters specially trained in safely handling asbestos can take care of the job.
Certified asbestos abatement specialists can remove old lead paint and properly prep the siding to paint. Licensed contractors have the right safety gear and equipment as well.
This ensures a high quality result you can enjoy for years without worrying about asbestos exposure for you or your family.
You can absolutely paint over asbestos siding safely with the right precautions during prep work and painting. Just monitor your asbestos cement boards for any deterioration and damage. When the panels start showing their age, replacement provides the best solution.
With a fresh coat of paint on your asbestos siding and some beautiful new exterior home colors, you can upgrade your home’s appearance and protect your siding for years to come!