Asbestos siding was commonly used on homes and buildings from the 1930s through the 1970s for its durability and fire-resistant properties. While intact and sealed asbestos siding poses little risk, deterioration over time can lead to exposure. Painting asbestos siding is an effective way to seal and protect it, preventing the release of harmful asbestos fibers. However, special care must be taken when preparing and painting asbestos siding to avoid disturbing the material.
Can You Paint Asbestos Siding?
Yes, you can safely paint asbestos cement siding as long as proper safety precautions are taken to prevent releasing asbestos fibers. The keys are using safe preparation techniques and high quality exterior paint.
Painting asbestos siding has several benefits:
- Seals and encapsulates asbestos fibers to prevent deterioration
- Restores appearance and provides aesthetic improvement
- Helps prevent damage from moisture, wind, debris, etc.
- Extends lifespan of siding by protecting from weathering
- Eliminates health risks associated with damaged asbestos materials
It’s best to hire an experienced asbestos abatement company for removing asbestos siding. However, painting can provide an affordable alternative to safely seal the siding and eliminate hazards.
If your asbestos siding is severely damaged, crumbling, or breaking apart, it’s recommended to have it removed and replaced. For siding in good condition, paint encapsulation is a safe option. Always inspect the area thoroughly and perform test patches before starting.
Preparing Asbestos Siding for Painting
Proper surface preparation is crucial before painting asbestos siding. The goal is to thoroughly clean the siding without damaging it or releasing asbestos fibers. Here are some recommended tips for safe prep work:
Cleaning the Surface
- Use a pressure washer on a low setting to gently clean and rinse the siding. Don’t use high pressure.
- Scrub with a long-handled nylon brush and detergent or TSP cleaner solution. Avoid abrasive brushes.
- Rinse thoroughly with the pressure washer and let the surface fully dry.
- Carefully scrape off any loose paint with a plastic scraper. Do not sand or scrape aggressively.
- Clean out any cracks, holes, or gaps in the siding using wet methods and vacuum with a HEPA filter.
Repairing Minor Damage
- Use exterior grade wood or cement filler to carefully patch small holes or cracks. Allow repairs to fully cure before painting.
- For larger damaged areas, cut away broken siding and replace with new fiber cement board. Avoid cutting asbestos siding.
- Seal any open seam gaps with silicone caulk. Tool smoothly to create a proper paint surface.
Priming the Surface
- Prime cleaned asbestos siding with a high quality oil-based primer like Kilz. This helps further seal and encapsulate the surface.
- If using latex paint, tint the primer close to your finish coat color for better coverage.
- Two coats of primer may be needed for optimal sealing, especially on bare or porous areas. Allow proper drying time between coats.
Proper prep removes surface contaminants, seals damage spots, and creates an optimal base for painting. Always wear proper PPE during any asbestos disturbance.
Asbestos Paint Encapsulation Methods
The key to safely painting asbestos siding is using proper encapsulation methods to seal in hazardous fibers. Two standard techniques are used:
Bridging Encapsulation
This method covers the surface with a thick film coating that creates a durable seal over the asbestos material. High build paints and coatings are applied to bridge over cracks, pores, and surface imperfections. The coating forms a solid barrier to prevent fiber release.
Penetrating Encapsulation
Penetrating sealants are applied first to soak into the asbestos matrix and bind fibers together. This prevents loose fibers from becoming airborne. A thick topcoat is then applied for additional protection. Sealers like Crown 250 Sealant are ideal for penetration on textured surfaces.
Combining both methods provides maximum encapsulation. An oil-based penetrating primer seals the surface, while high quality acrylic latex paint provides a thick bridging topcoat. This “belt and suspenders” approach helps ensure a durable fiber seal.
Choosing the Best Paint for Asbestos Siding
The right paint is critical for durably encapsulating asbestos siding. 100% acrylic latex exterior paint is highly recommended by asbestos control experts. Avoid paints with biocides or solvents that could degrade asbestos materials over time.
Here are the key qualities to look for in paint for asbestos siding encapsulation:
- 100% acrylic latex binder for flexibility and durability
- High build formula to fully seal the textured surface
- Vapor permeable to allow siding to breathe and prevent moisture damage
- Excellent adhesion and blocking resistance
- Soap and water cleanup without hazardous solvents
- Retention of color and gloss over time
- Meets ASTM D-16 Standard for encapsulant paints
Top quality acrylic latex paint brands like Sherwin-Williams Duration or Benjamin Moore Aura are ideal for durably encapsulating asbestos siding. An elastomeric paint provides maximum elasticity to bridge cracks and expand/contract with the siding.
Oil-based paint can also effectively seal asbestos siding. Alkyd enamels provide a hard, glossy finish that resists weathering. Select mold/mildew-resistant paint if the area is prone to frequent moisture.
Painting Techniques for Asbestos Siding
Follow these safe application techniques when painting asbestos siding:
- Use airless spray painting whenever possible for the smoothest finish. Keep the gun 12-15 inches from the surface and overlap strokes.
- If spraying isn’t practical, use good quality brushing or rolling techniques. Work methodically and gently.
- Apply paint generously to create a thick sealing coat that fully encapsulates the surface.
- Work in small sections and maintain a wet edge to prevent lap marks and uneven coverage.
- Allow proper drying time between coats as specified by the paint manufacturer.
- Apply at least two finish coats for complete protection, using vertical strokes to seal board edges.
- Caulk all seams, cracks, and openings after painting for an additional barrier.
- Avoid disturbing or damaging the siding when painting. Do not scrape, sand, or scrub hard.
Proper paint application techniques ensure even coverage and prevent releasing asbestos fibers during the painting process. Using the right tools and methods makes a big difference.
Asbestos Painting Safety Precautions
Painting asbestos siding requires strict safety precautions to prevent asbestos exposure. Here are some key guidelines:
- Wear an OSHA-approved respirator mask with proper cartridges while disturbing asbestos.
- Use disposable coveralls, gloves, and head covering during prep and painting.
- Follow wet work methods like damp sponging versus dry sanding or scraping.
- Use thick bead of caulk when filling holes to avoid dust. Wipe up excess with a wet cloth.
- Keep pets, children, and bystanders away from the work area.
- Work in calm weather to avoid stirring up dust. Mist surfaces with water as needed.
- Double bag all asbestos waste immediately in 6 mil plastic and dispose of properly.
- Clean up well after working using wet rags and a HEPA vacuum.
- Shower immediately after finishing and launder clothes separately.
- Use precautions when spraying paint including eye/face protection, respirator, and drop cloths. Stand upwind when spraying.
- Purchase asbestos liability insurance in case of property damage or personal injury claims.
- Consider hiring a certified asbestos control professional if the siding is severely damaged or you are unable to take proper safety precautions.
Asbestos was once considered a “miracle material” but is now known to be extremely hazardous when fibers become airborne. Take every precaution necessary to encapsulate the asbestos siding and prevent fiber release during painting.
Cost to Paint Asbestos Siding
Painting asbestos siding costs an average of $1.50 to $3 per square foot. Factors like your location, contractor rates, number of coats needed, and surface prep work will impact the total cost.
For a typical 1500 square foot home, expect to pay $2,250 to $4,500 to paint all asbestos siding surfaces. Here’s a breakdown of average costs:
- Surface cleaning and prep: $0.25 – $0.75 per sq.ft
- Primer coat: $0.75 – $1.25 per sq.ft
- Two finish coats: $1.25 – $2 per sq.ft
- Paint materials: $100 – $500
- Equipment rental: $50 – $200
- Asbestos disposal fees: $100 – $300
- Labor for prep & painting: $1000 – $3000
Professional asbestos abatement contractors typically charge around $5 per square foot to fully encapsulate and paint asbestos siding. DIY costs can be under $2 per square foot with proper prep and application work.
Proper maintenance helps extend the life of encapsulated asbestos siding. Expect to repaint every 7-10 years as needed to maintain the protective seal. The initial prep work makes re-coating much simpler.
Always account for the cost of proper asbestos safety gear like respirators, disposable coveralls, HEPA vacuums, and 6 mil plastic sheeting in your painting budget. Proper PPE will allow you to work safely.
Maintaining Painted Asbestos Siding
Here are some tips for properly maintaining painted asbestos siding:
- Inspect encapsulated siding each year for any cracks, damage, or deterioration. Make spot repairs as needed.
- Plan to re-coat every 7-10 years or when paint film starts looking worn. Follow original surface prep and painting steps.
- Clean siding annually with low pressure rinse. Re-apply caulk if gaps appear.
- Avoid disturbing siding through pressure washing, planting gardens near the foundation, or attaching fixtures through the boards.
- Keep trees and bushes trimmed back from the siding to prevent damage from branches.
- If siding shows severe cracking, crumbling, or separation, have it assessed by an asbestos abatement pro.
- Properly repair or replace damaged sections of encapsulated siding using asbestos-safe methods.
- Dispose of any asbestos debris like old caulk or broken sections in sealed plastic bags.
Ongoing maintenance preserves the protective paint film and prevents hazardous fiber release from damaged asbestos siding. Monitor your encapsulated siding and make repairs promptly.
Removal and Disposal of Asbestos Siding
While painting is an option for sealing intact asbestos siding, removal is recommended if the siding is severely damaged, deteriorated, or you plan to reside the home. Do not attempt to remove asbestos siding yourself. Hire trained, licensed asbestos abatement contractors to safely remove and dispose of the hazardous material.
The average cost to remove asbestos siding is $5 to $9 per square foot, or $7,500 to $13,500 for a 1500 sq.ft. home. Abatement pros use specialized tools, containment procedures, personal protective equipment, and hazardous waste disposal best practices.
Removing asbestos siding requires extensive safety protocols like:
- Plastic containment around work area to control fiber release
- Negative air system with HEPA filtration
- Worker decontamination station
- Water spray to keep materials wet
- Approved asbestos disposal at regulated landfills
Replacement siding like vinyl, fiber cement, wood, or composite boards offer attractive and safe alternatives to deteriorated asbestos siding. Consult local codes – some areas require asbestos siding to be removed prior to residing a home.
Conclusion
Asbestos siding was used for decades without knowledge of the severe health risks it poses. While intact, sealed asbestos siding is considered non-friable and relatively safe, deterioration can lead to hazardous asbestos dust. Painting using proper encapsulation techniques provides an affordable way to seal, restore, and safely maintain asbestos siding. With the right prep work, paint materials, application techniques, safety gear, and ongoing maintenance, asbestos siding can be effectively and safely encapsulated. Always use proper precautions when dealing with this dangerous material.
