Meta description: Learn what asphalt roll roofing material is, where it works best, how it compares with shingles, and what to know about installation, cost, and maintenance.
Asphalt roll roofing material offers a practical way to cover sheds, garages, porches, and other buildings with low-slope roofs. It comes in wide rolls, installs with fewer seams than many small roofing pieces, and typically costs less upfront than asphalt shingles. However, roll roofing is not right for every roof: slope, drainage, product instructions, and local building rules all matter. Knowing the differences among roll roofing products can help property owners choose a system that fits the building and avoid common installation problems.
What Is Asphalt Roll Roofing Material?
Asphalt roll roofing is a flexible roofing product supplied in rolls rather than individual shingles. Most products use a felt or fiberglass base saturated or coated with asphalt, with a mineral-granule surface on exposed areas. The asphalt helps resist water, while the reinforcement provides strength and the granules protect the surface from sunlight and wear.
Product construction varies. Some rolls are intended as exposed, finished roofing; others are underlayment or base sheets that must be covered by another roofing layer. A product described as “roll roofing” is not automatically suitable as a finished roof. Buyers should check the package label, technical data sheet, and installation instructions before purchase.
In everyday use, “rolled roofing” often refers to mineral-surfaced asphalt products for sheds and utility buildings. It is different from many commercial modified bitumen systems, which may use multiple layers, specialized membranes, or heat-welded seams. The names can overlap in retail listings, so product specifications are more reliable than broad category labels.
Common Types Of Asphalt Roll Roofing
Mineral-Surfaced Roll Roofing
This is the familiar exposed-surface product for small or simple roofs. Mineral granules cover the top face, and a smoother underside is secured to the roof deck with approved fasteners or roofing cement, depending on the product. It is often chosen for sheds, detached garages, and similar structures where cost and straightforward coverage are priorities.
Smooth-Surface Roll Roofing
Smooth-surface rolls are generally used as a base or interply sheet in a roofing assembly, rather than as a finished exposed roof. Their suitability depends on the specific product and system. A homeowner should not assume that a smooth roll can be left uncovered; doing so may expose it to weather and ultraviolet damage it was not designed to withstand.
Self-Adhered And Modified Bitumen Rolls
Some low-slope roofing membranes use asphalt modified with polymers to improve flexibility or performance. They may be self-adhered, cold-applied, or installed with specialized equipment. These products differ from basic mineral-surfaced roll roofing in materials, installation methods, and intended assemblies. Follow the manufacturer’s system instructions, including requirements for primers, laps, and compatible substrates.
Where Roll Roofing Works Best
Asphalt roll roofing is typically considered for simple roofs with limited complexity. It can suit a shed, workshop, porch, or detached garage when the roof slope and deck meet the product’s requirements. Broad, uninterrupted roof planes are easier to cover than roofs with many valleys, dormers, vents, and intersecting surfaces, which require careful detailing.
Roof slope is a key consideration. Many roll roofing products are intended for low-slope applications, but the minimum permitted slope varies by product and installation method. A roof that is too flat may hold water; one with a steeper pitch may require a different installation approach or material. Use the slope range stated in the product instructions and confirm that it meets local code.
Roll roofing is not a universal substitute for shingles. Asphalt shingles are designed for sloped roofs and have overlapping individual units, while roll roofing covers larger areas with continuous sheets and fewer field seams. Neither system is appropriate for every building, and local code may limit where particular products can be used.
Advantages And Limitations
| Feature | Potential benefit | Important limitation |
|---|---|---|
| Upfront material cost | Often lower than many alternatives | Price depends on product, region, and accessories |
| Roll format | Covers broad areas quickly | Seams and edges still need precise detailing |
| Installation | Can be simpler than shingle work on a plain roof | Manufacturer instructions and safe roof access are essential |
| Roof geometry | Works well on uncomplicated surfaces | Complex roofs may be difficult to flash and seal reliably |
| Service life | Can protect suitable utility buildings | Often shorter-lived than higher-grade roofing systems |
The main attraction is economy: the material is sold in broad rolls, and a simple roof can require less cutting and placement than one covered with individual shingles. Roll roofing can also be relatively lightweight, which may matter on certain small structures, though the roof framing and deck still need to be sound.
The trade-offs include a more utilitarian appearance and generally more limited durability than many premium roofing choices. Heat, ultraviolet exposure, standing water, poor ventilation, loose fasteners, and weak seam work can shorten service life. Roll roofing should not be treated as a way to conceal a deteriorated roof deck or unresolved drainage problem.
How To Estimate Material Needs
Start by measuring each roof plane, then calculate its area. For a rectangular section, multiply its length by its width. Add the areas of separate planes and account for eaves, rakes, valleys, and other details according to the product’s layout requirements.
Roll dimensions and coverage vary by product. The stated roll area may not equal the usable installed coverage because overlaps and end laps consume material. Check the manufacturer’s coverage figure, and allow for cuts and waste. Roofs with several edges or penetrations generally need more material than a plain rectangle of the same area.
Accessories can include underlayment, roofing cement, approved fasteners, drip edge, flashing, and replacement decking. The correct list depends on the roof assembly and local requirements. A supplier or roofing contractor can help check the estimate, but the product instructions remain the controlling reference for compatible materials and overlap dimensions.
Installation Basics And Safety
Installation details differ among products, so the instructions for the exact roll are essential. In general, a successful installation starts with a dry, clean, sound deck and appropriate edge and penetration details. The roof should be checked for rot, loose sheathing, protruding fasteners, and areas that could trap water before new material is installed.
- Confirm suitability. Verify the product’s approved roof slope, deck type, underlayment requirements, and local code acceptance.
- Prepare the surface. Repair damaged decking and install specified edges, underlayment, or other components in the required sequence.
- Plan the layout. Position courses so water flows over laps rather than into them, and follow the maker’s instructions for side laps and end joints.
- Secure the roofing. Use only the specified fasteners, adhesive, or combination, with the required spacing and placement.
- Detail vulnerable areas. Carefully handle eaves, rakes, walls, vents, and other penetrations using compatible flashing and approved methods.
Roofing work carries a serious fall risk. Ladders, roof edges, slippery surfaces, wind, heat, and overhead hazards require planning and appropriate fall protection. Work should stop in unsafe weather. A professional roofer is a sensible choice when the roof is steep, elevated, damaged, or complex, or when the installer is uncertain about flashing or code requirements.
Cost Factors And Comparison With Shingles
Asphalt roll roofing is often marketed as a budget-friendly option, but the total project cost is more than the price per roll. Estimates may include labor, tear-off and disposal, deck repairs, underlayment, flashing, edge metal, fasteners, sealants, and access equipment. Regional labor rates and roof complexity can make two similar-sized projects cost very different amounts.
Compared with asphalt shingles, roll roofing can reduce material and installation expenses on a basic roof. Shingles, however, are available in a wider range of styles and are commonly selected for homes and other prominent buildings. Their performance also depends on correct installation, ventilation, flashing, and product quality. A fair comparison considers the complete roof system and expected maintenance—not just the initial material price.
To compare bids, ask contractors to identify the exact product, roof preparation, underlayment, flashing work, disposal, warranty coverage, and any exclusions. A low quote that omits deck repairs or critical edge details may not represent the lowest long-term cost.
Expected Lifespan And Maintenance
There is no single service-life number for all asphalt roll roofing. Longevity depends on product quality, climate, roof slope, drainage, exposure, installation, and maintenance. Basic roll roofing generally has a more limited service life than many higher-end roof systems, so it is often selected for buildings where lower initial cost is more important than maximum longevity or appearance.
Inspect the roof periodically and after major storms. Look for lifted or split seams, exposed fasteners, loose edges, missing granules, blisters, punctures, and signs of water intrusion inside the building. Keep gutters and drainage paths clear. Promptly address small defects using repairs compatible with the roofing product; an incompatible patch can fail or damage the surface.
Repairs are not a substitute for replacing a roof that has widespread deterioration, repeated leaks, or a compromised deck. If water is entering, the source may be flashing or drainage rather than the visible spot directly above the stain. A qualified roofer can assess the full assembly and distinguish a localized repair from a larger problem.
Building Codes, Warranties, And Product Labels
Local building codes and adopted standards determine what roofing materials and assemblies are allowed. Requirements can vary by jurisdiction and may address slope, fire classification, underlayment, wind resistance, and installation. The International Residential Code and International Building Code are widely used model codes, but local authorities adopt and amend codes separately. Check with the local building department before starting work.
Product labels and technical documents should identify intended use, required slope, coverage, installation method, and any limitations. Warranty terms may require installation by specified methods, use of compatible components, or maintenance. A warranty does not guarantee that a roof will never leak, and it may not cover damage from improper installation, poor drainage, or building movement.
How To Choose Asphalt Roll Roofing Material
Before buying, compare products on intended application, minimum slope, reinforcement, surface finish, coverage after laps, installation method, and warranty. Confirm that the product is suitable as an exposed roof covering if it will be left visible. Check that the deck and planned accessories are compatible, and verify any code requirements with the local building department.
For a simple outbuilding with an appropriate slope, mineral-surfaced asphalt roll roofing may provide a low-cost covering when installed correctly. For a residence, a complex roof, or a building where appearance and long-term durability are priorities, shingles or a professionally designed low-slope membrane may be more suitable. The best choice depends on the complete roof assembly, not the roll alone.
Reliable Sources For Further Guidance
- International Code Council publishes model building codes adopted and modified by local jurisdictions.
- National Association of Home Builders provides building and remodeling resources for consumers and professionals.
- Occupational Safety and Health Administration offers guidance on fall hazards and fall protection in construction.
- For installation and warranty specifics, consult the technical data and instructions published by the manufacturer of the exact roofing product.