Roof Assemblies
Roof coverings, flashing, drainage, and roofing materials
Sections
Scope
Governs design, materials, construction, and quality of roof assemblies. This chapter covers roof coverings, flashing, drainage, and all rooftop installations.
Roof Covering Materials
Roofs shall be covered with materials as set forth in Sections R904 and R905. Class A, B, or C roofing shall be installed where required by law or where the roof edge is less than 3 feet from a lot line. Classification tested per ASTM E108 or UL 790.
Fire-retardant-treated shingles and shakes.
Fire-retardant-treated wood shakes and shingles shall be treated by impregnation with chemicals by the full-cell vacuum-pressure process, in accordance with AWPA C1.
Building-integrated photovoltaic product.
Building-integrated photovoltaic (BIPV) products installed as the roof covering shall be tested, listed and labeled for fire classification in accordance with UL 7103. Class A, B or C BIPV products shall be installed where the edge of the roof is less than 3 feet (914 mm) from a lot line.
Rooftop-mounted photovoltaic panel systems.
Rooftop-mounted photovoltaic panel systems installed on or above the roof covering shall be tested, listed and identified with a fire classification in accordance with UL 2703.
Weather Protection
Parent section for weather protection requirements including decking, flashing, and crickets.
General — Weather Protection
Roof decks shall be covered with approved roof coverings per R905. Roof assemblies must provide weather protection for the building. Flashing shall direct water to the roof or exterior of the building.
Flashing
Flashings shall be installed at wall and roof intersections, wherever there is a change in roof slope or direction, and around roof penetrations. Corrosion-resistant flashing material required. One of the most frequently cited sections in supplement documentation.
Flashing Locations
Flashing required at: roof-to-wall intersections, changes in roof slope, roof-to-chimney junctions, valleys, around dormers, at vent pipes and other penetrations, and at the perimeter of roof areas including eaves and rakes where required.
Crickets and Saddles
Section R903.2.2 — Crickets and Saddles. A cricket or saddle shall be installed on the ridge side of any chimney or penetration more than 30 inches (762 mm) wide as measured perpendicular to the slope. Cricket or saddle c...
Coping (NM-Specific)
NM-specific requirement for plastered parapets (common in Southwestern architecture). Requires seamless permeable waterproof cover capping entire parapet, extending 4 inches on wall side, properly lapping roof membranes. Expanded metal lath over cover before stucco/plaster. No penetrating fasteners on horizontal parapet surfaces.
Roof Drainage
All roofs shall be designed to drain. Roof drainage must be installed and maintained to prevent ponding. Where gutters are used, they must be designed per gutter sizing tables or per approved engineering.
Secondary (Emergency Overflow) Drains or Scuppers
Secondary emergency overflow drains or scuppers required where roof perimeter extends above roof (parapet walls). Overflow drains same size as primary with inlet 2 inches above low point, OR scuppers 3x size of drains with 4-inch minimum opening height.
Roof Covering Application — Scope
Establishes requirements for application of roof coverings. New roof coverings shall comply with applicable provisions. Materials shall be applied per manufacturer instructions and the IRC.
Compatibility of materials.
Roof assemblies shall be of materials that are compatible with each other and with the building or structure to which the materials are applied.
Material specifications and physical characteristics.
Roof covering materials shall conform to the applicable standards listed in this chapter.
Roof Recovering vs Replacement
New roof coverings may be installed over existing coverings under certain conditions. Not permitted when: existing roof is wet or deteriorated, when installing slate/clay/concrete tile, when existing is wood shake/shingle, or when the structure cannot support additional weight. Maximum two layers of roof covering on any roof portion.
Requirements for Roof Coverings
Comprehensive section covering underlayment, asphalt shingles, metal panels, tile, and other roof covering systems.
Roof Covering Application — General
Roof coverings shall be applied per manufacturer instructions. Underlayment per Table R905.1.1. Critical table for determining underlayment requirements based on roof slope and covering type.
Metal Roof Panels
Minimum slope 3:12 for lapped, nonsoldered-seam panels without applied sealant; 0.5:12 for standing seam. Attached to structural supports per approved manufacturer installation instructions. Corrosion-resistant fasteners required.
Deck requirements.
Metal roof panel roof coverings shall be applied to solid or spaced sheathing, except where the roof covering is specifically designed to be applied to spaced supports.
Material Standards
METAL PANELS - Must meet standards in Table R905.10.2. Corrosion resistant required.
Deck Slope
METAL PANEL SLOPES - Lapped without sealant: 3:12. Lapped with sealant: 0.5:12. Standing seam: 0.25:12.
Attachment.
Metal roof panels shall be secured to the supports in accordance with this chapter and the manufacturer’s installation instructions. In the absence of manufacturer’s installation instructions, the following fasteners shall be used: 1.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Underlayment (OK Amendment)
Underlayment materials must conform to ASTM standards. OKLAHOMA AMENDMENT: Ice barrier underlayment is NOT required statewide (explicitly stated as "NO" in Table R301.2(1)).
Modified bitumen roofing.
The installation of modified bitumen roofing shall comply with the provisions of this section and the manufacturer’s approved installation instructions.
Slope.
Modified bitumen roofing shall have a design slope of not less than one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
Material standards.
Modified bitumen roofing shall comply with the standards in Table R905.11.2.
Base sheet.
A base sheet that complies with the requirements of Section 1507.11.2 of the International Building Code, ASTM D1970 or ASTM D4601 shall be permitted to be used with a modified bitumen cap sheet.
Application.
Modified bitumen roofs shall be installed in accordance with this chapter and the manufacturer’s instructions.
Ice Barriers
Section R905.1.2 — Ice Barriers. In areas where there has been a history of ice forming along the eaves causing a backup of water as designated in Table R301.2(1), an ice barrier shall be installed for asphalt shi...
Thermoset single-ply roofing.
The installation of thermoset single-ply roofing shall comply with the provisions of this section.
Slope.
Thermoset single-ply membrane roofs shall have a design slope of not less than 1/4 unit vertical in 12 units horizontal (2-percent slope) for drainage.
Material standards.
Thermoset single-ply roof coverings shall comply with ASTM D4637 or ASTM D5019.
Application.
Thermoset single-ply roofs shall be installed in accordance with this chapter and the manufacturer’s instructions.
Roofing - Indiana Ice Barrier Requirements (MANDATORY)
Indiana requires ice barrier throughout the state (Zones 4A/5A). Self-adhering polymer-modified bitumen sheet must extend from eave edge to minimum 24 inches INSIDE exterior wall line. Required in valleys and around penetrations. Northwest Indiana (lake effect areas) should consider 36" coverage. Common failure: measuring from fascia instead of inside wall line.
Thermoplastic single-ply roofing.
The installation of thermoplastic single-ply roofing shall comply with the provisions of this section.
Slope.
Thermoplastic single-ply membrane roofs shall have a design slope of not less than 1/4 unit vertical in 12 units horizontal (2-percent slope).
Material standards.
Thermoplastic single-ply roof coverings shall comply with ASTM D4434, D6754 or D6878.
Application.
Thermoplastic single-ply roofs shall be installed in accordance with this chapter and the manufacturer’s instructions.
Photovoltaic Shingles
Building-integrated photovoltaic (BIPV) roof panels and shingles used as roof coverings shall comply with UL 7103. Must also comply with the applicable requirements of the roof covering type they replace.
Slope.
Sprayed polyurethane foam roofs shall have a design slope of not less than 1/4 unit vertical in 12 units horizontal (2-percent slope) for drainage.
Material standards.
Spray-applied polyurethane foam insulation shall comply with ASTM C1029, Type III or IV or ASTM D7425.
Application.
Foamed-in-place roof insulation shall be installed in accordance with this chapter and the manufacturer’s instructions. A liquid-applied protective coating that complies with Table R905.14.3 shall be applied not less than 2 hours nor more than 72 hours following the application of the foam.
Foam plastics.
Foam plastic materials and installation shall comply with Section R316.
Liquid-applied roofing.
The installation of liquid-applied roofing shall comply with the provisions of this section.
Slope.
Liquid-applied roofing shall have a design slope of not less than 1/4 unit vertical in 12 units horizontal (2-percent slope).
Material standards.
Liquid-applied roofing shall comply with ASTM C836, C957, D1227, D3468, D6083, D6694 or D6947.
Application.
Liquid-applied roofing shall be installed in accordance with this chapter and the manufacturer’s installation instructions.
Rooftop-Mounted Photovoltaic Systems
Rooftop PV systems shall be installed per manufacturer instructions. Fire classification of roof assembly must be maintained. Setback from ridge and edges per fire code for firefighter access. Attachment shall not void roof warranty when possible.
Deck requirements.
Photovoltaic shingles shall be applied to a solid or closely-fitted deck, except where the roof covering is specifically designed to be applied over spaced sheathing.
Deck slope.
Photovoltaic shingles shall be used only on roof slopes of 2 units vertical in 12 units horizontal (2:12) or greater.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Material standards.
INSIGHTS Photovoltaic shingles shall be listed and labeled in accordance with UL 7103 or with both UL 61730-1 and UL 61730-2. INSIGHTS (2)
Attachment.
Photovoltaic shingles shall be attached in accordance with the manufacturer’s installation instructions.
Wind resistance.
Photovoltaic shingles shall comply with the classification requirements of Table R905.16.6 for the appropriate maximum basic wind speed.
Building-integrated photovoltaic (BIPV) roof panels applied directly to the roof deck.
The installation of BIPV roof panels shall comply with the provisions of this section, Section R324 and NFPA 70.
Deck requirements.
BIPV roof panels shall be applied to a solid or closely-fitted deck, except where the roof covering is specifically designed to be applied over spaced sheathing.
Deck slope.
BIPV roof panels shall be used only on roof slopes of 2 units vertical in 12 units horizontal (17-percent slope) or greater.
Underlayment.
Underlayment shall comply with Section 905.1.1.
Ice barrier.
Where required, an ice barrier shall comply with Section R905.1.2.
Ice barrier.
In areas where there has been a history of ice forming along the eaves causing a backup of water, as designated in Table R301.2, an ice barrier that consists of not less than two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall be used in lieu of no...
Material standards.
INSIGHTS BIPV roof panels shall be listed and labeled in accordance with UL 7103 or with both UL 61730-1 and UL 61730-2. INSIGHTS (2)
Attachment.
BIPV roof panels shall be attached in accordance with the manufacturer’s installation instructions. ➡ SECTION R906 ROOF INSULATION ES
Asphalt Shingles
Asphalt shingles shall comply with ASTM D3462 or D7158. Minimum slope 2:12. Fasteners per manufacturer but minimum four nails per strip shingle. Enhanced nailing (six nails) required in high-wind areas. The most common residential roofing material — referenced in most reroof scopes.
Sheathing Requirements
SOLID SHEATHING - Asphalt shingles require solid (not spaced) sheathing.
Slope
MINIMUM SLOPE - Asphalt shingles require minimum 2:12 slope.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Asphalt Shingle Fasteners
Nails shall be corrosion-resistant, minimum 12-gauge with 3/8-inch head. Minimum 3/4-inch penetration into sheathing or through the thickness of the sheathing, whichever is less. Staples permitted where allowed by manufacturer.
Wind resistance of asphalt shingles.
Asphalt shingles shall be tested in accordance with ASTM D7158. Asphalt shingles shall meet the classification requirements of Table R905.2.4.1 for the appropriate ultimate design wind speed.
Fasteners.
Fasteners for asphalt shingles shall be galvanized steel, stainless steel, aluminum or copper roofing nails, minimum 12-gage [0.105 inch (3 mm)] shank with a minimum 3/8-inch-diameter (9.5 mm) head, complying with ASTM F1667, of a length to penetrate through the roofing materials and not less than 3...
Asphalt Shingle Attachment — High Wind
In areas where design wind speed > 115 mph (3-second gust), shingle attachment shall be per high-wind attachment methods. This may include additional fasteners, enhanced sealant strips, or use of wind-rated shingles.
Ice Barrier
In areas where mean daily January temperature is 25°F or less, an ice barrier that consists of two layers of underlayment cemented together or a self-adhering polymer modified bitumen sheet shall extend from the eave edge to a point not less than 24 inches inside the exterior wall line. Common requirement in northern states.
Ice Barrier
ICE BARRIER REQUIRED: Virginia Climate Zones 4A/5A mandate ice barrier at ALL eaves. MINIMUM: 24 inches past exterior wall line. RECOMMENDED: 36 inches or second course line. Use self-adhering polymer-modified bitumen membrane (Grace Ice & Water Shield, GAF StormGuard, CertainTeed WinterGuard, or equivalent ASTM D1970 compliant product).
Asphalt Shingle Valleys
Valley linings shall be per Section R905.2.8.1 (open valleys) or R905.2.8.2 (woven/closed-cut valleys). Open valleys require minimum 24-inch wide corrosion-resistant metal flashing with a 4-inch splash diverter rib.
Base Flashing
BASE FLASHING - Min 26 gauge galvanized metal OR 77 lb mineral roll roofing.
Valley Flashing
VALLEY FLASHING: OPEN VALLEYS require 24" minimum width metal flashing (28-gauge galv. steel or equiv.). CLOSED VALLEYS require 36" minimum roll roofing or ice & water shield (ASTM D1970). Ice & water shield in valleys is BEST PRACTICE for Virginia climate. W-metal valleys provide superior water channeling.
Sidewall Flashing
SIDEWALL FLASHING - Step-flashing method required. Minimum 4" width.
Other flashing.
Flashing against a vertical front wall, as well as soil stack, vent pipe and chimney flashing, shall be applied in accordance with the asphalt shingle manufacturer’s printed instructions.
Drip Edge
DRIP EDGE - Required at eaves/gables. 1/4" min extension below sheathing, 2" back on roof. Fastened 12" o.c.
Clay and Concrete Roof Tile
Clay tile per ASTM C1167, concrete tile per ASTM C1492. Minimum slope 2.5:12. Tiles shall be fastened per Table R905.3.7 based on wind speed and exposure. Battens or direct deck attachment permitted depending on tile type and roof slope.
Deck requirements.
INSIGHTS Concrete and clay tile shall be installed only over solid sheathing. Exception:Spaced lumber sheathing in accordance with Section R803.1 shall be permitted in Seismic Design Categories A, B and C.
Deck slope.
Clay and concrete roof tile shall be installed on roof slopes of 21/2 units vertical in 12 units horizontal (25-percent slope) or greater.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Clay tile.
Clay roof tile shall comply with ASTM C1167.
Concrete tile.
Concrete roof tile shall comply with ASTM C1492.
Fasteners.
INSIGHTS Nails shall be corrosion resistant and not less than 11-gage [0.120 inch (3 mm)], 5/16-inch (11 mm) head, and of sufficient length to penetrate the deck not less than 3/4 inch (19 mm) or through the thickness of the deck, whichever is less.
Application.
INSIGHTS Tile shall be applied in accordance with this chapter and the manufacturer’s installation instructions, based on the following: 1. Climatic conditions.
Flashing.
At the juncture of roof vertical surfaces, flashing and counterflashing shall be provided in accordance with this chapter and the manufacturer’s installation instructions and, where of metal, shall be not less than 0.019 inch (0.5 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal.
Metal Roof Shingles
Metal roof shingles shall comply with applicable material standards. Minimum slope 3:12. Fasteners per manufacturer requirements. Corrosion-resistant attachment required.
Deck requirements.
Metal roof shingles shall be applied to a solid or closely fitted deck, except where the roof covering is specifically designed to be applied to spaced sheathing.
Deck Slope
METAL SHINGLES SLOPE - Minimum 3:12 slope required.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Material standards.
Metal roof shingle roof coverings shall comply with Table R905.10.3(1). The materials used for metal roof shingle roof coverings shall be naturally corrosion resistant or be made corrosion resistant in accordance with the standards and minimum thicknesses listed in Table R905.10.3(2).
Wind resistance of metal roof shingles.
INSIGHTS Metal roof shingles applied to a solid or closely fitted deck shall be tested in accordance with ASTM D3161, FM 4474, UL 580 or UL 1897.
Application.
Metal roof shingles shall be secured to the roof in accordance with this chapter and the approved manufacturer’s installation instructions.
Flashing.
Roof valley flashing shall be of corrosion-resistant metal of the same material as the roof covering or shall comply with the standards in Table R905.10.3(1).
Mineral-surfaced roll roofing.
The installation of mineral-surfaced roll roofing shall comply with this section.
Deck requirements.
Mineral-surfaced roll roofing shall be fastened to solidly sheathed roofs.
Deck slope.
Mineral-surfaced roll roofing shall not be applied on roof slopes below 1 unit vertical in 12 units horizontal (8-percent slope).
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Material standards.
Mineral-surfaced roll roofing shall conform to ASTM D3909 or ASTM D6380, Class M.
Application.
Mineral-surfaced roll roofing shall be installed in accordance with this chapter and the manufacturer’s instructions.
Slate shingles.
The installation of slate shingles shall comply with the provisions of this section.
Deck requirements.
Slate shingles shall be fastened to solidly sheathed roofs.
Deck slope.
Slate shingles shall be used only on slopes of 4 units vertical in 12 units horizontal (33-percent slope) or greater.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Material standards.
Slate shingles shall comply with ASTM C406.
Application.
Minimum headlap for slate shingles shall be in accordance with Table R905.6.5. Slate shingles shall be secured to the roof with two fasteners per slate.
Flashing.
Flashing and counterflashing shall be made with sheet metal. Valley flashing shall be not less than 15 inches (381 mm) wide.
Wood shingles.
INSIGHTS The installation of wood shingles shall comply with the provisions of this section. INSIGHTS (1)
Deck requirements.
Wood shingles shall be installed on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall be not less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners.
Solid sheathing required.
In areas where the average daily temperature in January is 25°F (-4°C) or less, solid sheathing is required on that portion of the roof requiring the application of an ice barrier.
Deck slope.
Wood shingles shall be installed on slopes of 3 units vertical in 12 units horizontal (25-percent slope) or greater.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Material standards.
INSIGHTS Wood shingles shall be of naturally durable wood and comply with the requirements of Table R905.7.4. INSIGHTS (1) TABLE R905.7.4 WOOD SHINGLE MATERIAL REQUIREMENTS MATERIAL MINIMUM GRADES APPLICABLE GRADING RULES Wood shingles of naturally durable wood 1, 2 or 3 CSSB
Application.
INSIGHTS Wood shingles shall be installed in accordance with this chapter and the manufacturer’s instructions. Wood shingles shall be laid with a side lap not less than 11/2 inches (38 mm) between joints in courses, and two joints shall not be in direct alignment in any three adjacent courses.
Valley flashing.
Roof flashing shall be not less than No.
Label required.
Each bundle of shingles shall be identified by a label of an approved grading or inspection bureau or agency.
Wood shakes.
INSIGHTS The installation of wood shakes shall comply with the provisions of this section. INSIGHTS (1)
Deck requirements.
Wood shakes shall be used only on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall be not less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners.
Solid sheathing required.
In areas where the average daily temperature in January is 25°F (-4°C) or less, solid sheathing is required on that portion of the roof requiring an ice barrier.
Deck slope.
Wood shakes shall only be used on slopes of 3 units vertical in 12 units horizontal (25-percent slope) or greater.
Underlayment.
Underlayment shall comply with Section R905.1.1.
Ice barrier.
Where required, ice barriers shall comply with Section R905.1.2.
Interlayment.
Interlayment shall comply with ASTM D226, Type I.
Material standards.
Wood shakes shall comply with the requirements of Table R905.8.5.
Application.
INSIGHTS Wood shakes shall be installed in accordance with this chapter and the manufacturer’s installation instructions. Wood shakes shall be laid with a side lap not less than 11/2 inches (38 mm) between joints in adjacent courses.
Shake placement.
The starter course at the eaves shall be doubled and the bottom layer shall be either 15-inch (381 mm), 18-inch (457 mm) or 24-inch (610 mm) wood shakes or wood shingles. Fifteen-inch (381 mm) or 18-inch (457 mm) wood shakes shall be permitted to be used for the final course at the ridge.
Valley flashing.
Roof valley flashing shall be not less than No. 26 gage [0.019 inch (0.5 mm)] corrosion-resistant sheet metal and shall extend not less than 11 inches (279 mm) from the centerline each way.
Label required.
Each bundle of shakes shall be identified by a label of an approved grading or inspection bureau or agency.
Built-up roofs.
The installation of built-up roofs shall comply with the provisions of this section and the manufacturer’s approved installation instructions.
Slope.
Built-up roofs shall have a design slope of not less than 1/4 unit vertical in 12 units horizontal (2-percent slope) for drainage, except for coal-tar built-up roofs, which shall have a design slope of a minimum 1/8 unit vertical in 12 units horizontal (1-percent slope).
Material standards.
Built-up roof covering materials shall comply with the standards in Table R905.9.2 or UL 55A.
Application.
Built-up roofs shall be installed in accordance with this chapter and the manufacturer’s instructions.
Canales and Scuppers (NM Amendment)
NM-specific requirement for canales (traditional Southwestern roof drain spouts projecting through parapet walls). Metal pan lining required extending 6 inches minimum past inside of parapet, sealed to prevent moisture infiltration. Canales must be adequately sized for roof area.
Roofing - Arizona Requirements (Including Phoenix Cool Roof Mandate)
AZ roofing requirements include Phoenix cool roof mandate (SRI 64), tile installation per TRI manual, and underlayment degradation concerns unique to desert heat. Monsoon wind uplift is primary design consideration.
Roofing - Hawaii Hurricane-Resistant Requirements
Hawaii roofing requirements mandate hurricane-resistant construction statewide. Wind speeds 105-130 mph require continuous load path, hurricane straps at all roof-to-wall connections, enhanced sheathing nailing (6"/6"), and corrosion-resistant materials. No ice barrier required (Climate Zone 1). Product approval for wind resistance and salt air corrosion required.
Roofing - Mississippi Gulf Coast Hurricane Requirements (POST-KATRINA)
Mississippi Gulf Coast roofing requires hurricane-resistant construction. Wind speeds 150-180 mph on immediate coast, 115-130 mph inland. Continuous load path MANDATORY. Hurricane straps at ALL roof connections. Enhanced sheathing nailing (6"/6" for 140+ mph). NO ice barrier required (Zones 2A/3A). WBDR on coast requires impact glazing/shutters. Very heavy termite zone.
Roof Assemblies - Tennessee Requirements
ROOFING - TN requirements vary by region: West TN (Zone 3A) generally no ice barrier needed. East TN (Zone 4A, high elevation) requires ice barrier at eaves. Sevier County WUI: Class A roof MANDATORY, no wood shake/shingles. Wind uplift per IRC Table R802.11. All roofing requires Class A/B/C fire rating.
Roofing Requirements - Vermont (IRC 2015/2018 + RBES 2020)
Roofing in Vermont must address extreme snow loads (50-150+ psf), ice dam formation, and Zone 6A cold-humid conditions. Ice barrier underlayment is REQUIRED statewide. Municipalities with adopted codes enforce IRC R905; all areas enforce RBES 2020 energy requirements for attic insulation and ventilation.
Roof Ventilation
Enclosed attics and enclosed rafter spaces must be cross-ventilated. Minimum net free ventilation area 1/150 of the area ventilated. Ratio may be 1/300 when specific conditions are met (vapor retarder, balanced intake/exhaust). Ventilation is critical for shingle warranty and moisture management.
Material standards.
Above-deck thermal insulation board shall comply with the standards in Table R906.2.
Rooftop-Mounted Equipment
Mechanical equipment and other equipment mounted on roofs shall be supported by approved means. Equipment shall not invalidate the fire classification of the roof assembly. Flashing required around all roof penetrations per R903.2.
Reroofing
Parent section governing work on existing roofs.
General
Reroofing must comply with Chapter 9 requirements.
Structural and construction loads.
The structural roof components shall be capable of supporting the roof covering system and the material and equipment loads that will be encountered during installation of the roof covering system.
Recovering Versus Replacement
ROOF TEAR-OFF REQUIRED when: water-soaked, wood/slate/tile existing, or 2+ existing layers.
Roof recover.
The installation of a new roof covering over an existing roof covering shall be permitted where any of the following conditions occur: 1. Where the new roof covering is installed in accordance with the roof covering manufacturer’s approved instructions 2.
Roof recover not allowed.
INSIGHTS A roof recover shall not be permitted where any of the following conditions occur: 1. Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
Roof Recovering
RECOVERING OVER SHAKES - Must cover with gypsum/mineral fiber if creating concealed space.
Reinstallation of materials.
INSIGHTS Existing slate, clay or cement tile shall be permitted for reinstallation, except that damaged, cracked or broken slate or tile shall not be reinstalled.
Flashings
FLASHING RECONSTRUCTION - Per manufacturer instructions. Prime metal before bitumen adhesion.