Replacement Asbestos Siding
Replacement asbestos siding refers to modern, safe, non-asbestos building materials engineered specifically to match, repair, or completely substitute for vintage asbestos-cement exterior cladding shingles. Installed on millions of North American homes between 1920 and the late 1970s, rigid transite shingles frequently suffer localized damage from storms, fallen tree limbs, or home additions, requiring specialized replacement options that preserve architectural aesthetics without introducing toxic mineral hazards.
The Challenge: Sourcing Non-Asbestos Shingle Matches
Vintage asbestos-cement siding shingles—manufactured under historic brand names like Transite, Keasbey & Mattison, Carey, and Flintkote—were constructed by combining Portland cement with fifteen to twenty-five percent chrysotile fibers. Pressed with intricate surface textures like striated wood grain, wavy edges, or straight-cut cedar shakes, these rigid, fireproof shingles offered unmatched durability. However, because asbestos manufacturing was phased out in the 1970s and 1980s, finding exact replacement tiles presents significant architectural challenges.
Homeowners facing a few broken, cracked, or missing asbestos siding tiles cannot simply visit a home improvement store and buy asbestos shingles. Fortunately, building material manufacturers developed modern fiber cement replacement shingles—most notably GAF WeatherSide—that combine Portland cement with safe organic cellulose wood fibers. These non-hazardous replacement tiles replicate vintage transite dimensions, hole punch locations, and surface wood-grain striations almost identically.
Compare vintage asbestos siding with modern non-asbestos fiber cement replacement shingles:
| Material Specification | Vintage Asbestos Siding Shingle | Modern Fiber Cement Replacement | Structural Compatibility | Environmental Safety |
|---|---|---|---|---|
| Core Reinforcing Fiber | 15% to 25% Chrysotile Asbestos | Cellulose wood fiber pulp | Identical rigidity & weight | Modern shingle contains 0% asbestos |
| Surface Texture & Style | Deep striated faux wood grain | Matching striated embossed grain | Seamless visual aesthetic match | Non-hazardous modern composite |
| Edge Profile Formats | Straight-edge, wavy, thatched edge | Straight, wavy, thatched available | Direct drop-in replacement | Pre-primed for custom painting |
| Standard Dimensions | 12" x 24" (typical thickness 5/32") | 12" x 24" (exact metric match) | Aligns with existing coursing lines | Fasteners match vintage holes |
| Fire Rating Class | Non-combustible Class A fire rated | Non-combustible Class A fire rated | Maintains exterior fire resistance | Safe to handle and cut |
Repair Techniques: Replacing Individual Damaged Siding Tiles
Replacing isolated broken asbestos siding shingles requires careful, non-destructive carpentry techniques designed to avoid cracking adjacent brittle tiles. The procedure begins by slipping a specialized flat shingle ripper tool beneath the overlapping tile above the damaged piece to cut or hook the hidden mounting nails. Technicians avoid using heavy hammers or pry bars directly against neighboring tiles, as the shock easily fractures aged, brittle cement shingles.
Once the fasteners are severed, the damaged shingle fragments are carefully extracted under wet misting conditions to prevent any dust from aerosolizing. A modern fiber cement replacement tile (such as GAF WeatherSide) is slid into place, aligned with the existing horizontal coursing, and fastened through pre-drilled holes using non-corrosive galvanized or stainless steel siding nails. Technicians seal the joints with high-grade exterior elastomeric caulk and apply matching paint.
Review replacement options for addressing damaged or failing asbestos siding:
| Remediation Approach | Operational Method | Cost Impact | Aesthetic Outcome | Asbestos Abatement Mandate |
|---|---|---|---|---|
| Spot Tile Replacement | Replace broken tiles with fiber cement | Low ($15 to $35 per tile) | Excellent; seamless color match | Non-abatement repair protocol |
| Full Fiber Cement Siding | Full tear-off and James Hardie siding | High ($12,000 to $25,000+) | Brand new modern exterior | Mandatory certified full abatement |
| Vinyl Siding Layover | Wrap over intact siding with foam & vinyl | Moderate ($8,000 to $16,000) | Modern maintenance-free finish | Avoids abatement; entombs tiles |
| Elastomeric Coating | Clean & paint existing sound shingles | Low ($3,000 to $7,000) | Refreshes vintage historic look | Preserves existing sound siding |
| Engineered Wood Siding | Full tear-off and LP SmartSide siding | High ($10,000 to $22,000) | Durable contemporary appearance | Mandatory certified full abatement |
Full House Siding Options: Vinyl Wrap vs. Complete Abatement
When a home's exterior asbestos siding is extensively cracked, weathered, or failing across multiple elevations, homeowners must choose between full siding layover and complete certified abatement. The most popular and economical whole-house solution is wrapping over the existing asbestos siding. Siding contractors install rigid fanfold extruded polystyrene insulation board directly over the intact asbestos shingles, followed by new insulated vinyl or composite siding, safely encapsulating the asbestos behind modern cladding.
If the homeowner chooses complete removal—often necessary for historic district compliance or deep energy retrofits—the work must be executed by a licensed asbestos abatement contractor. Technicians mist the shingles with surfactant water, gently back out fasteners, and unhook intact tiles without breaking them. Solid transite debris is palletized, wrapped in double layers of six-mil poly sheeting, and transported to a permitted construction asbestos landfill.
How to Safely Replace a Broken Asbestos Siding Shingle
Follow these five carpentry steps to replace a damaged asbestos siding tile with modern fiber cement.
Mist Damaged Tile with Soapy Water
Spray the damaged shingle and surrounding tiles thoroughly with surfactant water to keep any loose fibers grounded.
Sever Fasteners Using a Shingle Ripper
Slide a flat shingle ripper tool beneath the overlapping tile above to cut or dislodge the hidden fasteners.
Carefully Extract Broken Shingle Pieces
Manually remove the broken asbestos pieces without snapping them, sealing the wet debris directly into a heavy plastic bag.
Slide In Modern Fiber Cement Replacement
Slide a matching GAF WeatherSide fiber cement shingle into the coursing, aligning pre-punched mounting holes.
Secure with Galvanized Nails and Caulk
Fasten the new shingle with hot-dipped galvanized nails, caulk the nail heads and seams, and paint to match the home.
Frequently Asked Questions (8 Questions Answered)
Q1: Can you still buy asbestos siding today?
No, asbestos siding manufacturing was permanently discontinued in the late 1970s and 1980s due to severe health hazards.
Q2: What is the modern replacement for asbestos siding?
Modern fiber cement shingles (such as GAF WeatherSide) match vintage dimensions and textures perfectly using safe cellulose fibers.
Q3: Can you side over existing asbestos siding?
Yes, installing rigid foam insulation board and new vinyl or composite siding directly over intact asbestos shingles is widely approved.
Q4: Can you paint asbestos siding?
Yes, painting asbestos siding with high-quality exterior acrylic latex or elastomeric paint is an approved, effective encapsulation method.
Q5: Can you power wash asbestos siding before painting?
No, pressure washing asbestos siding is illegal in many jurisdictions because it blasts toxic fibers into the ambient air and soil.
Q6: How much does it cost to replace a few asbestos shingles?
Replacement fiber cement shingles cost about $15 to $25 per tile, with professional labor averaging $50 to $100 per tile repair.
Q7: Is removing asbestos siding considered hazardous?
Yes, while intact shingles are non-friable, snapping, breaking, or dropping them releases regulated hazardous asbestos dust.
Q8: What nails should be used for replacement fiber cement siding?
Use hot-dipped galvanized or stainless steel ring-shank siding nails to prevent rust streaking on the new shingles.
Final Thoughts & Key Takeaways
In conclusion, understanding replacement asbestos siding provides essential clarity, practical strategies, and actionable advice. By incorporating these foundational insights, adhering to verified safety guidelines, and following structured best practices, you ensure reliable, long-term outcomes while preventing common mistakes. Stay informed, consult certified professionals when needed, and maintain consistent quality care.