Asphalt and Tar Roofing Materials: A Comprehensive Guide

The roofing market in the United States relies heavily on asphalt and tar-based materials for durability, cost efficiency, and ease of installation. This guide compares asphalt roofing materials with tar-based options, explains where each excels, and outlines installation, performance, maintenance, and environmental considerations. Readers will gain a clear understanding of how asphalt shingles, built-up roofing, and tar products fit into modern roofing strategies and how to choose the right material for a specific project.

Understanding Asphalt Roofing Materials

Asphalt roofing materials are primarily water-resistant and designed to protect structures from weather while offering strong value. The most common form is asphalt shingles, which use a fiberglass or organic base coated with asphalt and mineral granules. These shingles come in various profiles, including 3-tab, architectural, and premium styles, with color options tailored to regional aesthetics and architectural codes. Asphalt shingles are known for quick installation, moderate cost, and broad availability.

Key characteristics include a relatively high strength-to-weight ratio, good wind resistance for most standard installations, and a service life typically ranging from 15 to 30 years depending on climate, underlayment, and roofing design. Maintenance is generally straightforward, with inspections focusing on curling edges, lifted tabs, and granule loss. From an environmental perspective, asphalt shingles are widely recyclable at end of life, and many systems incorporate recycled content in the shingle mat or granules.

Tar Roofing: Built-Up and Bitumen Systems

Tar roofing refers to older and some specialized systems that rely on tar or bitumen as the primary waterproofing layer. Built-up roofing (BUR) is the most common tar-based system, consisting of alternating layers of bitumen (asphalt or coal tar), reinforcing fabrics, and a protective surface layer such as gravel or a cap sheet. These roofs are favored for flat or low-slope applications and provide excellent waterproofing when properly installed. Modern BUR often uses modified bitumen sheets for improved performance and installation efficiency.

Tar-based roofs offer strong moisture resistance, proven track records on commercial and industrial buildings, and excellent durability in multiple pore-structure environments. However, they can be heavier and require more skilled labor during installation. They may also involve more intensive maintenance in terms of seam integrity and surface protection. Environmental considerations include heating requirements for installation and potential VOC emissions during application, though newer products strive to minimize these impacts.

Choosing Between Asphalt and Tar Roofing Materials

The decision between asphalt and tar roofing materials depends on roof geometry, climate, budget, and project goals. Asphalt shingles are typically ideal for sloped residential roofs, offering quick installation, a wide selection of colors, and favorable warranty options. Tar-based BUR systems are well-suited for flat or low-slope commercial roofs, where superior waterproofing and long-term resilience are valuable, though they may involve higher upfront labor costs and more complex maintenance.

Consider these decision factors:

• Slope and Geometry: Asphalt shingles require a minimum slope for proper drainage, while BUR performs well on flat or near-flat surfaces.
• Weight and Structure: Tar systems are heavier; structural assessments may be needed where old roofs are replaced.
• Durability: BUR can offer extended waterproofing life in certain climates but may require more frequent inspection of seams and surfacing.
• Maintenance: Shingles typically demand less specialized maintenance, whereas tar systems need professional inspection for membrane integrity.
• Cost: Initial costs often favor asphalt shingles; long-term costs may favor tar systems in appropriate settings due to life cycles and warranty terms.

Performance and Longevity

Performance hinges on climate, roof design, and installation quality. Asphalt shingles resist wind uplift well in many regions and provide a good balance of cost and lifespan. High-wind areas may require architectural shingles or specialty options with enhanced wind resistance. Proper attic ventilation and underlayment contribute to shingle longevity by reducing heat buildup and moisture accumulation.

Tar-based BUR systems deliver robust waterproofing and can handle standing water on low-slope roofs when properly installed. They are often preferred for roofs where drainage is poor or where a longer track record of exposure resistance is desired. The longevity of BUR systems is influenced by the number of plies, the quality of bitumen, and the performance of the surface ballast, which shields membranes from UV damage.

Installation Considerations

Choosing the right installation approach is essential for maximizing performance. Asphalt shingles require a stable, dry substrate, appropriate nailing patterns, and compatible underlayment. Fasteners, tab alignment, and correct venting contribute to wind resistance and leak protection. For tar-based BUR, crews must manage asphalt temperatures, supervise the layering sequence, and ensure surface protection to prevent surface cracking and punctures. Proper ventilation and edge detailing help prevent moisture buildup and heat-related damage in both systems.

Professional installation ensures compliance with local building codes and manufacturer warranties. Homeowners should verify contractor credentials, prior project history, and material warranties before committing to an asphalt or tar-based system. A detailed inspection plan, including drainage assessment and structural compatibility checks, supports a durable roof that meets expected performance.

Maintenance and Repairs

Maintenance strategies differ between asphalt and tar roofing. Asphalt shingles benefit from periodic cleaning of debris, inspections for curling or missing granules, and prompt replacement of damaged sections. Regular inspections after major weather events help identify wind uplift or hail damage before it progresses. For tar-based BUR, maintenance focuses on seam integrity, surface ballast condition, and any exposed asphalt surfaces. Weatherproof repairs may involve resealing seams or applying protective coatings as recommended by the manufacturer.

Both systems benefit from annual inspections, prompt handling of leaks, and proactive ventilation checks. Prolonged neglect can lead to accelerated degradation, higher repair costs, and reduced roof life. Modern asphalt shingles often include warranty protections that cover manufacturing defects and gradual degradation, while BUR warranties emphasize waterproofing performance and system integrity over time.

Environmental and Sustainability Considerations

Environmental impact is a major consideration in choosing roofing materials. Asphalt shingles frequently incorporate recycled content in mats and granules, and many recycling programs accept old shingles for repurposing into pavement materials. Tar-based systems, while durable, may involve more energy-intensive manufacturing processes and higher VOC emissions during installation, though newer products aim to reduce emissions and improve recyclability. Both systems can be selected with energy-efficient underlayments and reflective or cool roofing options to improve building efficiency and indoor comfort.

End-of-life options include recycling, repurposing, or proper disposal in accordance with local regulations. Contractors can provide guidance on updated recycling avenues and manufacturer programs to minimize environmental impact while preserving roof performance.

Cost Considerations and Value

Cost is a critical factor in selecting roofing materials. Asphalt shingles typically offer the lowest initial cost per square foot, rapid installation, and broad availability of colors and styles. Over the life of the roof, maintenance and potential replacement costs influence total cost of ownership. Tar-based BUR systems usually incur higher upfront costs due to material complexity and labor demands but may deliver longer-term resilience in certain climates and roof configurations.

Value should be assessed through a total-cost-of-ownership lens, incorporating expected service life, warranty terms, energy savings from reflective surfaces, and potential maintenance expenditures. In residential contexts, asphalt shingles remain the most common choice for cost-conscious homeowners, while commercial projects may justify BUR or modified bitumen routes for flat or low-slope roofs.

What to Ask Prospective Roofing Contractors

Before selecting a material, homeowners and facility managers should consult with qualified roofing professionals. Questions to ask include:

• What is the expected service life for the chosen material in the local climate?
• What warranty terms are available, and what do they cover?
• How will ventilation, insulation, and underlayment affect performance?
• What maintenance schedule do you recommend after installation?
• What recycling or disposal options are offered at end of life?

Clear communication helps ensure the selected asphalt or tar roofing system delivers the best balance of protection, value, and long-term performance for the building.