“Asphalt tar roofing sheets” can refer to several products, from asphalt-saturated roofing felt to mineral-surfaced rolled roofing and asphalt shingles. These materials are not interchangeable, and roofing “tar” is not necessarily the same thing as asphalt. Knowing the differences helps homeowners choose a roof covering that fits the roof’s slope, local weather, budget, and building code. This guide explains common asphalt roofing sheets, how they are installed, what they may cost, and how to maintain them.
What Are Asphalt Roofing Sheets?
Asphalt roofing sheets are flexible roofing products made with asphalt or asphalt-based compounds. Depending on the product, the material may include a fiberglass or organic reinforcement, a protective mineral surface, or a smooth coating. Some products are supplied in rolls; asphalt shingles are supplied as smaller overlapping pieces rather than continuous sheets.
The phrase asphalt tar roofing sheets is common in searches, but asphalt and coal tar are different materials. Modern residential roofing products are generally asphalt-based. Coal-tar pitch is a separate material used in some specialized roofing systems, particularly certain low-slope applications. Product labels, technical data sheets, and the roof specification should identify the material accurately.
“Roofing felt” can also be confusing. Traditional felt is commonly asphalt-saturated, while newer underlayments may be synthetic. Underlayment is installed beneath the roof covering and is not automatically a finished, weatherproof roof on its own. A roll of mineral-surfaced cap sheet, by contrast, may be designed as an exposed roof covering when installed as part of an approved system.
Common Types Of Asphalt Roofing Sheets
Asphalt-Saturated Roofing Felt
Roofing felt is a water-resisting layer installed between the roof deck and the outer covering, such as asphalt shingles. It can provide temporary protection during installation and help manage moisture that gets beneath the covering. It is usually underlayment, not the roof’s primary exposed surface. Product type, roof slope, local code, and the chosen roof covering affect which underlayment is appropriate.
Mineral-Surfaced Roll Roofing
Roll roofing is a flexible, asphalt-based sheet with a mineral-granule surface. It is commonly used on sheds, garages, porches, and other buildings where a low-cost roof covering is suitable. Some products are installed with exposed fasteners, while others use adhesive or a combination of methods. Installation requirements vary, so the manufacturer’s instructions are essential.
Roll roofing is often considered for low-slope roofs, but “low-slope” does not mean “flat.” A product may have a minimum slope requirement and may need specific lap widths, underlayment, or fastening patterns. Water that ponds on a roof can cause problems even when the material is designed for low-slope use.
Modified Bitumen Sheets
Modified bitumen roofing is an asphalt-based membrane enhanced with polymers. It is commonly supplied in rolls and used on low-slope roofs. Depending on the system, sheets may be installed using self-adhesive backing, cold-applied adhesive, mechanical fasteners, or heat welding. Torch-applied systems require specialized training and careful fire controls; open-flame work should not be treated as a routine do-it-yourself task.
Modified bitumen is generally installed as a roof system, which may include a base sheet and one or more additional layers. The correct assembly depends on the product approval, deck, insulation, drainage, and building requirements. A single roll of membrane does not necessarily provide all components needed for a code-compliant roof.
Asphalt Shingles
Asphalt shingles are not sheets in the roll-roofing sense, but they are a major asphalt roofing category. Common types include three-tab and architectural (laminated) shingles. They are designed for sloped roofs and installed in overlapping courses over underlayment. Shingles are usually not the right direct substitute for a low-slope membrane; minimum slope and special underlayment requirements must be checked for the specific product.
Asphalt Roofing Sheets Compared
| Product | Typical role | Roof form | Key consideration |
|---|---|---|---|
| Asphalt-saturated felt | Underlayment | Usually beneath shingles or another covering | Not normally a finished exposed roof |
| Mineral-surfaced roll roofing | Exposed roof covering | Some low-slope or accessory roofs | Follow minimum slope and lap details |
| Modified bitumen | Low-slope membrane system | Low-slope roofs | Installation method and assembly matter |
| Asphalt shingles | Exposed roof covering | Sloped roofs | Use within the product’s slope and fastening limits |
Advantages And Limitations
Affordability and availability are important reasons asphalt roofing products are common in the United States. Many contractors know how to install them, and products are sold in a range of grades and formats. Some roll products can cover a roof quickly, while shingles offer a familiar appearance and broad color selection.
Asphalt-based materials can also be repaired or replaced in sections in some circumstances. However, a repair must match the existing roof system and address the cause of damage, such as failed flashing, poor drainage, or movement in the deck. Covering a leak with a patch without fixing its source can leave hidden moisture damage in place.
Limitations include sensitivity to installation quality, heat, ultraviolet exposure, and standing water, depending on the product. Lightweight roll roofing may have a shorter useful life than a properly installed, higher-grade roof system. Asphalt products can also be vulnerable to wind uplift, impact, and temperature-related aging. No material guarantees that a roof will withstand every storm.
Environmental considerations matter, too. Asphalt roofing creates construction and replacement waste. Recycling options vary by location and product, so homeowners can ask local waste authorities or contractors about disposal and recycling. A roof’s energy performance depends on the entire assembly, including color, ventilation, insulation, and attic conditions—not just the surface material.
Cost Of Asphalt Roofing Sheets
Roofing costs vary widely by region, roof size, slope, access, tear-off needs, labor, and the condition of the deck. Roll roofing materials generally cost less per square foot than many more elaborate roof systems, but the installed price includes preparation, underlayment or base sheets, flashing, fasteners or adhesives, disposal, and labor. Modified bitumen systems and complicated low-slope details can cost considerably more than the roll material alone suggests.
Contractor estimates are usually based on roof area, but roofers often measure in “squares”: one roofing square equals 100 square feet. A quote should state the product and system, number of layers, tear-off and disposal charges, deck repairs, flashing details, ventilation work, and warranty terms. Compare complete installed estimates, not just the price of a roll or bundle.
For a useful comparison, request written bids that identify the manufacturer and product name, installation method, required underlayment, minimum slope, and any accessories. Ask whether the quote includes permits and inspection fees where required. A low bid that omits flashing replacement or deck repairs may not represent the final project cost.
How Long Do Asphalt Roofing Sheets Last?
There is no single lifespan for asphalt roofing sheets. Roofing felt is a concealed layer whose service life depends on the covering above it and the roof assembly. Mineral-surfaced roll roofing and modified bitumen have different performance expectations, while shingles vary by product, climate, installation, and maintenance. Manufacturer warranty periods are not the same as a guaranteed service life.
Heat, intense sun, freeze-thaw cycles, wind, hail, poor drainage, and inadequate ventilation can affect roof aging. So can installation errors, such as incorrect laps, exposed or misplaced fasteners, and poorly detailed edges. The roof deck and flashing may fail before the field material does. A qualified inspection can distinguish surface wear from problems requiring repair or replacement.
Installation And Building-Code Considerations
Start by confirming the roof’s slope, deck type, drainage, and intended use. The chosen product must be approved for that application and installed according to its current instructions. Local building codes may specify underlayment, fastening, wind resistance, fire classification, and inspection requirements. The International Residential Code and local amendments provide requirements for residential roofing, but the locally adopted code is what governs a specific project.
Key installation details include:
- Deck preparation: The roof deck should be sound, clean, and suitable for the specified system. Damaged sheathing may need replacement.
- Underlayment and base layers: Use only the layers and overlaps required by the product instructions and code.
- Weather and drainage: Install in suitable conditions, maintain positive drainage, and address gutters, valleys, and roof penetrations.
- Fasteners and seams: Follow the specified fastener type, spacing, location, and seam overlap. Small deviations can compromise performance.
- Flashing: Detail chimneys, walls, vents, edges, and drains as part of the roofing system, not as afterthoughts.
Homeowners considering do-it-yourself work should also account for fall hazards, ladder safety, and the risk of fire during heat-applied installation. Many roofing projects require permits or inspections. The local building department can explain applicable rules, and a licensed, insured roofing contractor can confirm the system’s suitability.
Maintenance And Common Problems
Periodic visual checks can reveal lifted edges, missing granules, cracked or blistered areas, loose fasteners, damaged flashing, and debris blocking drainage. Inspections are especially useful after severe weather, but walking on a roof can damage the material or cause a fall. Ground-level viewing or a professional inspection is safer for many homeowners.
Common problems include water entering at seams, edges, valleys, and penetrations; blistering or cracking; wind-lifted material; and leaks caused by clogged drains or ponding water. The visible stain on an interior ceiling may not sit directly below the roof opening because water can travel along the deck or framing. A roofer should trace the leak rather than simply seal the nearest visible spot.
Keep gutters and roof drains clear, trim branches that rub against the roof, and avoid pressure washing or harsh chemicals unless the manufacturer specifically permits them. Repairs should use compatible materials and follow the system’s details. If widespread deterioration, repeated leaks, or soft decking is present, a professional assessment can determine whether a repair or full replacement is more appropriate.
How To Choose The Right Asphalt Roofing Product
The best choice depends on the roof, not only on the material’s price. A steep residential roof may be suited to asphalt shingles, while a low-slope garage roof may require a roll product or membrane specifically approved for that slope. A shed with limited service-life expectations may have different priorities from a primary home where durability, appearance, and warranty support are important.
Before buying, verify the product’s intended use, minimum slope, installation method, fire classification, wind rating, and warranty exclusions. Check whether the warranty requires a particular underlayment, ventilation arrangement, or certified installer. For a home sale, insurance claim, or major remodel, retain the product documentation, permit records, invoices, and photographs of concealed layers.
Reliable product information is available from manufacturers’ installation instructions and technical data sheets, local building departments, and roofing trade organizations such as the National Roofing Contractors Association. The International Code Council publishes model codes that jurisdictions may adopt or amend. Those sources help clarify whether a material is suitable for a specific roof and which installation details apply.