Roll Roofing Code in Georgia

Georgia Adopts IRC R905.5 for Roll Roofing

Georgia regulates mineral-surfaced roll roofing through the International Residential Code, adopted with state-specific amendments by the Georgia Department of Community Affairs (DCA). Section R905.5 of the IRC governs roll roofing as a distinct roof covering category, separate from asphalt shingles, built-up roofing, and single-ply membranes.

Roll roofing is the simplest and least expensive code-compliant roof covering available in Georgia. It consists of a single layer of asphalt-saturated felt or fiberglass mat, coated with asphalt and surfaced with mineral granules. The product ships in rolls (typically 36 inches wide, 36 feet long) that cover approximately one square (100 square feet) per roll. Installation requires basic tools: a hammer, roofing nails, a utility knife, and lap cement.

That simplicity comes with significant limitations. Roll roofing provides the shortest service life, the lowest wind resistance, and the least weather protection of any roof covering permitted under Georgia code. The IRC allows roll roofing because it satisfies minimum weatherproofing requirements for the structures where it applies. But "code-compliant" and "recommended" are different standards. 1 Source Roofing installs roll roofing when the project scope calls for it, but we recommend upgrading to shingles or a membrane system for any structure that protects living space, stored valuables, or long-term investments.

Local jurisdictions enforce R905.5 through their building departments. Building inspectors in Alpharetta, Marietta, Sandy Springs, and throughout metro Atlanta verify compliance during the final roofing inspection when a permit applies.

For a broad overview of how Georgia adopts and enforces roofing codes, see our Georgia residential roofing code guide. This page focuses on the specific provisions of R905.5 and the practical limitations of roll roofing in metro Atlanta's climate.

ASTM Material Standards for Roll Roofing

IRC R905.5 references two ASTM standards for roll roofing products. Each standard governs a different product type with distinct installation methods and performance characteristics.

ASTM Standard	Product Type	Key Characteristics	Application Method
ASTM D6380	Mineral-surfaced roll roofing	Fiberglass or organic mat, mineral granule surface	Nail-applied with lap cement at overlaps
ASTM D6509	Self-adhering roll roofing	Modified bitumen with factory adhesive backing	Peel-and-stick, no nails in field

ASTM D6380: Mineral-Surfaced Roll Roofing

ASTM D6380 covers traditional nail-applied roll roofing with a mineral granule surface. The standard tests tensile strength, tear resistance, and pliability (flexibility at low temperatures). The product comes in two styles:

• Full-coverage (exposed nail): The entire 36-inch width is granule-surfaced. Each course overlaps the one below by 2 to 4 inches, and nails along the overlap edge secure both the current course and the top edge of the course below.
• Selvage-edge (double coverage): Approximately half the roll width (17-19 inches) is granule-surfaced. The other half is a smooth, un-surfaced selvage that the next course covers and bonds to with lap cement. This provides double-layer coverage and better weather resistance than single-coverage application.

GAF produces the Ruberoid line of roll roofing products. CertainTeed, IKO, and Atlas also manufacture ASTM D6380-compliant roll roofing. The products are commodity items with minimal differentiation between manufacturers. Product selection usually comes down to availability at the local roofing supply house.

ASTM D6509: Self-Adhering Roll Roofing

Self-adhering roll roofing eliminates the need for field nailing in the roof field. A factory-applied adhesive backing bonds the membrane to the roof deck when the release liner is removed. Nails or fasteners are still required at the edges and at any overlap where the adhesive alone cannot resist wind uplift forces.

Self-adhering products provide a better seal than nail-applied roll roofing because the adhesive creates a continuous bond rather than relying on discrete nail points. The trade-off is higher material cost and sensitivity to installation temperature. The adhesive requires a minimum substrate temperature of 40 to 50 degrees Fahrenheit to bond correctly. Georgia's mild winters make this less of a concern than in northern states, but early morning installations in January and February can encounter substrate temperatures below the adhesive's bonding threshold.

Both ASTM D6380 and D6509 products meet Georgia code when installed according to R905.5 and the manufacturer's instructions. Your contractor should verify the ASTM compliance marking on the roll packaging before installation begins.

Minimum Slope Requirements for Roll Roofing

Roll roofing has stricter slope minimums than single-ply membranes and built-up roofing. The single-layer construction and reliance on gravity for water shedding mean that roll roofing cannot perform on near-flat surfaces where other systems work.

Application Method	Minimum Slope	Coverage Type	Where Code Allows It
Exposed nail (single coverage)	1:12	Single layer, nailed at laps	Sheds, utility buildings, temporary applications
Concealed nail (single coverage)	1:12	Single layer, nails hidden under laps	Detached garages, carports
Selvage-edge (double coverage)	2:12	Double layer with lap cement bond	Low-slope residential, porch roofs
Self-adhering	1:12 (per manufacturer)	Full adhesive bond to substrate	Same as above, better wind resistance

The 1:12 minimum for single-coverage roll roofing is half the 2:12 minimum required for asphalt shingles. This allows roll roofing on low-slope structures where shingles cannot go, providing a code-compliant option for lean-to roofs, shed roofs, and other simple structures with minimal slope.

On roofs steeper than 4:12, roll roofing presents a different problem: appearance. The wide courses and horizontal lap lines are visible on steep roofs and create an industrial appearance that detracts from any residential property. Homeowners in Buckhead, Johns Creek, and Roswell with roll roofing on visible roof sections should plan for an upgrade to shingles during the next roof replacement. The aesthetic improvement alone increases curb appeal and property value.

Roll roofing meets code on low-slope structures where shingles cannot go. For any structure worth protecting, shingles or a membrane system provide the durability, wind resistance, and warranty that roll roofing cannot match.

Nail Patterns and Lap Cement Requirements

IRC R905.5 specifies the fastening methods and lap treatment that make roll roofing a functional (if limited) roof covering. The code references manufacturer installation instructions by incorporation, making those instructions part of the legal requirement.

Nail Specifications

Roll roofing uses the same nail specifications as asphalt shingles under IRC R905.2.5:

• Nail gauge: Minimum 12-gauge (0.105-inch diameter) for smooth shank
• Head diameter: Minimum 3/8 inch
• Deck penetration: Minimum 3/4 inch through the roof deck
• Material: Corrosion-resistant steel, stainless steel, or copper

Exposed-Nail Application

Exposed-nail application places nails along the top edge and at both ends of each course. The next course overlaps the nail heads by 2 to 4 inches. Nails along the top edge space 4 to 6 inches apart. End laps require nails on 2-inch spacing with lap cement covering the full overlap area.

This method is fast and simple but exposes every nail to weather when the granule surface above the nail head degrades. Over time, water wicks around the nail shafts, and the nail holes enlarge as the material shrinks and expands with thermal cycling. This degradation pattern is the primary reason exposed-nail roll roofing lasts only 5 to 10 years in Georgia's climate.

Concealed-Nail Application

Concealed-nail application places nails along the top edge of each course, then bonds the overlap of the next course over the nails with lap cement. No nails are exposed to weather. This method provides better water resistance than exposed-nail application but requires more lap cement and careful alignment to ensure full coverage of the nail heads.

Lap Cement Requirements

Lap cement (also called roofing cement or plastic cement) seals the overlapping edges of roll roofing courses. The cement must cover the full width of the overlap area in a continuous, uniform application. Air pockets, dry spots, or inadequate cement coverage create leak paths at every deficient point along the seam.

Georgia's summer heat softens roofing cement. On low-slope roofs, softened cement can flow out of the overlap zone, leaving exposed gaps. Winter cold makes cement brittle and prone to cracking. This thermal vulnerability is another factor in roll roofing's limited service life. The drip edge code also applies to roll roofing edges, requiring metal drip edge at eaves and rakes to control water runoff.

Service Life and Practical Limitations

Roll roofing has the shortest service life of any code-compliant roof covering material. Industry data and field experience in the Southeast place the expected lifespan at 5 to 15 years, with most installations in metro Atlanta reaching end of life between 7 and 12 years.

Why Roll Roofing Fails Faster

Several factors accelerate roll roofing degradation compared to asphalt shingles and membrane systems:

• Single-layer construction: Roll roofing provides one layer of protection. Asphalt shingles provide two to three overlapping layers at every point on the roof. When the single roll roofing layer degrades, water reaches the deck with no backup barrier.
• Thin material: Roll roofing is thinner than architectural shingles. The reduced material thickness means less asphalt coating to protect the mat from UV degradation and less granule depth to resist erosion.
• No self-sealing strip: Asphalt shingles include a factory-applied sealant strip that bonds shingle courses together under solar heat. Roll roofing relies on nails and lap cement, both of which degrade faster than polymer sealant strips.
• No wind rating: Roll roofing products do not carry ASTM D7158 or ASTM D3161 wind resistance classifications. The material lacks the structural design features (sealant strips, engineered nailing zones, multi-layer overlap) that give shingles their wind performance.
• No meaningful warranty: Manufacturers offer limited warranties on roll roofing, typically 5 to 10 years with significant exclusions. Compare this to the 25 to 50-year warranties available on GAF and CertainTeed architectural shingles installed by certified contractors.

Cost Comparison Over 30 Years

Roof Covering	Installed Cost (per sq ft)	Lifespan	30-Year Replacement Cycles	30-Year Total Cost
Roll roofing	$1.50 - $2.50	5-15 years	2-5 replacements	$4.50 - $12.50/sq ft
Architectural shingles	$3.50 - $5.50	25-40 years	0-1 replacement	$3.50 - $11.00/sq ft
TPO/EPDM membrane	$4.00 - $7.00	20-30 years	0-1 replacement	$4.00 - $14.00/sq ft

The 30-year cost analysis shows that roll roofing's low upfront price creates a false economy. Multiple replacement cycles, each with tear-off and disposal costs, drive the total cost of ownership above the cost of a single shingle installation. For homeowners in Alpharetta, Sandy Springs, and Marietta, the math is clear: roll roofing costs more over time and provides less protection at every point in its shorter life.

Roll roofing costs less today but costs more over 30 years. Multiple replacement cycles, each with labor and disposal, exceed the cost of a single shingle or membrane installation.

When Code Allows Roll Roofing and When It Does Not

Roll roofing meets Georgia code for any structure that falls under the IRC, provided the slope and installation requirements of R905.5 are satisfied. The code does not restrict roll roofing to specific building types. You can legally install roll roofing on a $3 million home in Buckhead if it meets the slope minimum and is installed per the manufacturer's instructions. Whether you should is a different question.

Where Roll Roofing Makes Sense

• Detached sheds and storage buildings: Structures with no conditioned space, no insulation, and minimal value. A garden shed, tool shed, or firewood shelter benefits from roll roofing's low cost and fast installation.
• Temporary repairs: After storm damage, roll roofing can provide temporary weather protection while you arrange for permanent repair or replacement. The material installs in hours and provides immediate protection while insurance claims process.
• Detached garages (non-habitable): If the garage does not contain conditioned living space, stored valuables, or finished interiors, roll roofing provides adequate protection at minimum cost.
• Properties slated for demolition or major renovation: If the structure will be torn down or gutted within 5 years, investing in a 30-year shingle roof does not make financial sense.

Where Roll Roofing Should Not Go

• Primary residences: Homes deserve the wind resistance, warranty coverage, and longevity that architectural shingles provide.
• Habitable accessory structures: Guest houses, pool houses, home offices, and studios contain conditioned space and valuables that warrant a proper roofing system.
• Any structure with insurance value: Insurance companies may not cover damage to buildings with roll roofing at the same level as buildings with standard roof coverings. Insurance claims are simpler and more successful with code-rated shingle or membrane systems.
• Visible roof sections: Roll roofing's industrial appearance detracts from the curb appeal of any residential property in metro Atlanta's premium neighborhoods.

Why 1 Source Recommends Upgrading from Roll Roofing

Roll roofing belongs on structures that do not warrant a long-term roofing investment. For every other application, a better option exists at a cost that pays for itself through longer service life, better weather protection, and higher property value.

Upgrade Path: Roll Roofing to Shingles

For steep-slope structures (2:12 and above), architectural asphalt shingles replace roll roofing with a product that provides 25 to 50-year service life, ASTM D7158 wind resistance ratings, manufacturer system warranties, and the appearance that metro Atlanta homeowners expect. The upgrade requires tearing off the existing roll roofing, inspecting and repairing the deck, installing proper underlayment, and applying shingles with the correct wind-rated fastener pattern.

Upgrade Path: Roll Roofing to Membrane

For low-slope structures (below 2:12), a TPO membrane, EPDM rubber membrane, or spray foam system replaces roll roofing with a product designed for flat and low-slope applications. These systems provide 20 to 40-year service life, proper wind uplift ratings, manufacturer warranties, and the waterproofing performance that roll roofing cannot match.

Free Inspection and Estimate

We inspect roll roofing conditions at no cost. Our project manager assesses the existing roof, evaluates the deck condition, identifies any storm damage or moisture intrusion, and provides an upgrade estimate that includes material options, labor, permit costs, and expected service life for each option.

We pull permits for every project that requires one. In Alpharetta, Sandy Springs, Johns Creek, Roswell, Marietta, and throughout the 30-mile radius we serve, we maintain active business licenses and know each jurisdiction's permit process. A closed permit with a passed inspection documents that your new roof meets Georgia building code.

Related Building Code and Technical Guides

These pages cover related code requirements and technical installation standards for Georgia roofing:

• Georgia Residential Roofing Code Guide -- Complete overview of IRC Chapter 9, permits, and inspections
• Asphalt Shingle Code Requirements -- IRC R905.2 standards for the most common upgrade from roll roofing
• Roof Underlayment Code Requirements -- Underlayment standards required under shingle and membrane systems
• Drip Edge Requirements -- Metal drip edge code for eaves and rakes
• Wind Speed Requirements -- ASCE 7 wind maps and fastener schedules for metro Atlanta
• Reroofing and Tear-Off Requirements -- When tear-off is required vs. recover installation
• TPO and PVC Roofing Code -- Membrane alternative for low-slope sections
• EPDM Rubber Roofing Code -- Rubber membrane alternative for flat sections
• Roofing Permit Requirements -- Permit process and inspection requirements by jurisdiction

Questions about upgrading from roll roofing? Call 1 Source Roofing at (404) 277-1377 for a free roof inspection and upgrade estimate.