SECTION 1513 — ACCESS TO ROOFTOP EQUIPMENT

ROOFING AND ROOF STRUCTURES

SECTION 1513 — ACCESS TO ROOFTOP EQUIPMENT

Access shall be provided to all mechanical equipment located on the roof as required by the Mechanical Code.

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OCCUPANCY F.R. F.R. One-hour N One-hour N H.T. One-hour N

A-1

N—No requirements for fire resistance.

NR—Nonrated roof coverings.

1Buildings that are not more than two stories in height and have not more than 6,000 square feet (557 m²) of projected roof area and where there is a minimum of 10 feet (3048 mm) from the extremity of the roof to the property line or assumed property line on all sides except for street fronts may have Class C roof coverings that comply with UBC Standard 15-2.

2See Section 308.2.2.

3Nonrated roof coverings may be used on buildings that are not more than two stories in height and have not more than 3,000 square feet (279 m²) of projected roof area and where there is a minimum of 10 feet (3048 mm) from the extremity of the roof to the property line on all sides except for street fronts.

4Unless otherwise required because of location, Group U, Division 1 roof coverings shall consist of not less than one layer of cap sheet, or built-up roofing consisting of two layers of felt and a surfacing material of 300 pounds per roofing square (14.6 kg/m²) of gravel or other approved surfacing material, or 250 pounds (12.2 kg/m²) of crushed slag.

a

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TABLE 15-B-1 1997 UNIFORM BUILDING CODE

1--150

TABLE 15-B-1—ASPHALT SHINGLE APPLICATION

ASPHALT SHINGLES

Not Permitted below 2 Units Vertical in 12 Units Horizontal (16.7% Slope) Roof Slope 2 Units Vertical in 12 Units Horizontal (16.7% Slope) to Less than

4 Units Vertical in 12 Units Horizontal (33.3% Slope) 4 Units Vertical in 12 Units Horizontal (33.3% Slope) and Over

1. Deck requirement Asphalt shingles shall be fastened to solidly sheathed roofs. Sheathing shall conform to Sections 2312.2 and 2320.12.9.

2. Underlayment

Temperate climate Asphalt strip shingles may be installed on slopes as low as 2 units vertical in 12 units horizontal (16.7% slope), provided the shingles are approved self-sealing or are hand sealed and are installed with an underlayment consisting of two layers of nonperforated Type 15 felt applied shingle fashion.

Starting with an 18-inch-wide (457 mm) sheet and a 36-inch-wide (914 mm) sheet over it at the eaves, each subsequent sheet shall be lapped 19 inches (483 mm) horizontally.

One layer nonperforated Type 15 felt lapped 2 inches (51 mm) horizontally and 4 inches (102 mm) vertically to shed water.

Severe climate:

In areas subject to wind-driven snow or roof ice buildup

Same as for temperate climate, and the two layers shall be solid cemented together with approved cementing material between the plies extending from the eave up the roof to a line 24 inches (610 mm) inside the exterior wall line of the building. As an alternative to the two layers of cemented Type 15 felt, an approved self-adhering, polymer modified, bituminous sheet may be used.

Same as for temperate climate, except that one layer No. 40 coated roofing or coated glass base shall be applied from the eaves to a line 12 inches (305 mm) inside the exterior wall line with all laps cemented together. As an alternative to the layer of No. 40 felt, a self-adhering, polymer modified, bituminous sheet may be used.

3. Attachment Combined systems, type of fasteners

Corrosion-resistant nails, minimum 12-gage³/8-inch (9.5 mm) head, or approved corrosion-resistant staples, minimum 16-gage¹⁵/16-inch (23.8 mm) crown width.

Fasteners shall comply with the requirements of Chapter 23, Division III, Part III.

Fasteners shall be long enough to penetrate into the sheathing³/4inch (19 mm) or through the thickness of the sheathing, whichever is less.

No. of fasteners¹ 4 per 36-inch to 40-inch (914 mm to 1016 mm) strip

2 per 9-inch to 18-inch (229 mm to 457 mm) shingle Exposure

Field of roof

Hips and ridges Per manufacturer’s instructions included with packages of shingles.

Hip and ridge weather exposures shall not exceed those permitted for the field of the roof.

Method Per manufacturer’s instructions included with packages of shingles.

4. Flashing Valleys

Other flashing Per Section 1508.2

Per Section 1509

1Figures shown are for normal application. For special conditions, such as mansard application and where roofs are in special wind regions, shingles shall be attached per the manufacturer’s instructions.

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1--151 TABLE 15-B-2—WOOD SHINGLE OR SHAKE APPLICATION

WOOD SHINGLES WOOD SHAKES

Not Permitted below 3 Units Vertical in 12 Units Horizontal

(25% Slope) Not Permitted below 4 Units Vertical in 12 Units Horizontal (33.3% Slope)¹

ROOF SLOPE See Table 15-C See Table 15-C

1. Deck requirement Shingles and shakes shall be applied to roofs with solid or spaced sheathing.

When spaced sheathing is used, sheathing boards shall not be less than 1 inch by 4 inches (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. When 4-inch (25 mm by 102 mm) spaced sheathing is installed at 10 inches (254 mm) on center, additional 1-inch-by-4-inch (25 mm by 102 mm) boards must be installed between the sheathing boards.

Sheathing shall conform to Sections 2312.2 and 2320.12.9.

2. Interlayment No requirements. One 18-inch-wide (457 mm) interlayment of Type 30 felt

shingled between each course in such a manner that no felt is exposed to the weather below the shake butts and in the keyways (between the shakes).

3. Underlayment

Temperate climate No requirements. No requirements.

Severe climate:

In areas subject to wind-driven snow or roof ice buildup

Two layers of nonperforated Type 15 felt applied shingle fashion shall be installed and solid cemented together with approved cementing material between the plies extending from the eave up the roof to a line 36 inches (914 mm) inside the exterior wall line of the building.

Sheathing shall be solid and, in addition to the interlayment of felt shingled between each course in such a manner that no felt is exposed to the weather below the shake butts, the shakes shall be applied over a layer of nonperforated Type 15 felt applied shingle fashion. Two layers of nonperforated Type 15 felt applied shingle fashion shall be installed and solid cemented together with approved cementing material between the plies extending from the eave up the roof to a line 36 inches (914 mm) inside the exterior wall line of the building.

4. Attachment

Type of fasteners Corrosion-resistant nails, minimum No. 14¹/₂-gage, 7/₃₂-inch (5.6 mm) head, or corrosion-resistant staples, when approved by the building official.

Corrosion-resistant nails, minimum No. 13-gage,⁷/₃₂-inch (5.6 mm) head, or corrosion-resistant staples, when approved by the building official.

Fasteners shall comply with the requirements of Chapter 23, Division III, Part III.

Fasteners shall be long enough to penetrate into the sheathing³/4inch (19 mm) or through the thickness of the sheathing, whichever is less.

No. of fasteners 2 per shingle 2 per shake

Exposure Field of roof

Hips and ridges Weather exposures shall not exceed those set forth in Table 15-C.

Hip and ridge weather exposure shall not exceed those permitted for the field of the roof.

Method Shingles shall be laid with a side lap of not less than 1¹/2inches (38 mm) between joints in adjacent courses, and not in direct alignment in alternate courses. Spacing between shingles shall be approximately¹/4inch (6.4 mm). Each shingle shall be fastened with two nails only, positioned approximately³/4 inch (19 mm) from each edge and approximately 1 inch (25 mm) above the exposure line. Starter course at the eaves shall be doubled.

Shakes shall be laid with a side lap of not less than 1¹/2inches (38 mm) between joints in adjacent courses. Spacing between shakes shall not be less than³/8inch (9.5 mm) or more than⁵/8 inch (15.9 mm) except for preservative-treated wood shakes, which shall have a spacing not less than

1/4inch (6.4 mm) or more than³/8inch (9.5 mm).

Shakes shall be fastened to the sheathing with two nails only, positioned approximately 1 inch (25 mm) from each edge and approximately 2 inches (51 mm) above the exposure line. The starter course at the eaves shall be doubled. The bottom or first layer may be either shakes or shingles. Fifteen-inch or 18-inch (381 mm or 457 mm) shakes may be used for the starter course at the eaves and final course at the ridge.

5. Flashing Valleys

Other flashing Per Section 1508.5

Per Section 1509

1When approved by the building official, wood shakes may be installed on a slope of not less than 3 units vertical in 12 units horizontal (25% slope) when an underlayment of not less than nonperforated Type 15 felt is installed.

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TABLE 15-D-1 1997 UNIFORM BUILDING CODE

1--152

TABLE 15-C—MAXIMUM WEATHER EXPOSURE

GRADE LENGTH 3 UNITS VERTICAL TO LESS THAN 4 UNITS VERTICAL

IN 12 UNITS HORIZONTAL (25% ≤ 33.3% SLOPE) 4 UNITS VERTICAL IN 12 UNITS HORIZONTAL (33.3% SLOPE)

× 25.4 for mm Wood Shingles

1. No. 1 16-inch 3³/₄ 5

2. No. 2¹16-inch 3¹/2 4

3. No. 3¹16-inch 3 3¹/2

4. No. 1 18-inch 4¹/4 5¹/2

5. No. 2¹18-inch 4 4¹/2

6. No. 3¹18-inch 3¹/₂ 4

7. No. 1 24-inch 5³/4 7¹/2

8. No. 2¹24-inch 5¹/2 6¹/2

9. No. 3¹24-inch 5 5¹/2

Wood Shakes²

10. No. 1 18-inch 7¹/2 7¹/2

11. No. 1 24-inch 10 10

12. No. 2 18-inch tapersawn shakes — 5¹/2

13. No. 2 24-inch tapersawn shakes — 7¹₂

1To be used only when specifically permitted by the building official.

2Exposure of 24-inch by³/8-inch (610 mm by 9.5 mm) resawn handsplit shakes shall not exceed 5 inches (127 mm) regardless of the roof slope.

TABLE 15-D-1—ROOFING TILE APPLICATION¹FOR ALL TILES

ROOF SLOPE 2¹/2UNITS VERTICAL IN 12 UNITS HORIZONTAL (21% Slope) TO LESS THAN 3 UNITS VERTICAL IN 12 UNITS

HORIZONTAL (25% Slope)

ROOF SLOPE 3 UNITS VERTICAL IN 12 UNITS HORIZONTAL (25% Slope) AND OVER

1. Deck requirements Solid sheathing per Sections 2312.2 and 2320.12.9

2. Underlayment

In climate areas subject to wind-driven snow, roof ice damming or special wind regions as shown in Chapter

16, Figure 16-1. Built-up roofing membrane, three plies minimum, applied per Section 1507.6. Surfacing not required.

Same as for other climate areas, except that extending from the eaves up the roof to a line 24 inches (610 mm) inside the exterior wall line of the building, two layers of underlayment shall be applied shingle fashion and solidly cemented together with an approved cementing material.

Other climate areas One layer heavy-duty felt or Type 30 felt side lapped

2 inches (51 mm) and end lapped 6 inches (153 mm).

3. Attachment²

Type of fasteners Corrosion-resistant nails not less than No. 11 gage,⁵/16-inch (7.9 mm) head. Fasteners shall comply with the requirements of Chapter 23, Division III, Part III. Fasteners shall be long enough to penetrate into the sheathing³/4inch (19 mm) or through the thickness of the sheathing, whichever is less. Attaching wire for clay or concrete tile shall not be smaller than 0.083 inch (2.11 mm) (No. 14 B.W. gage).

Number of fasteners^2,3 One fastener per tile. Flat tile without vertical laps, two

fasteners per tile. Two fasteners per tile. Only one fastener on slopes of

7 units vertical in 12 units horizontal (58.3% slope) and less for tiles with installed weight exceeding 7.5 pounds per square foot (36.6 kg/m²) having a width no greater than 16 inches (406 mm).⁴

4. Tile headlap 3 inches (76 mm) minimum.

5. Flashing Per Sections 1508.4 and 1509.

1In snow areas, a minimum of two fasteners per tile are required.

2In areas designated by the building official as being subject to repeated wind velocities in excess of 80 miles per hour (129 km/h) or where the roof height exceeds 40 feet (12 192 mm) above grade, all tiles shall be attached as follows:

2.1 The heads of all tiles shall be nailed.

2.2 The noses of all eave course tiles shall be fastened with approved clips.

2.3 All rake tiles shall be nailed with two nails.

2.4 The noses of all ridge, hip and rake tiles shall be set in a bead of approved roofer’s mastic.

3In snow areas, a minimum of two fasteners per tile are required, or battens and one fastener.

4On slopes over 24 units vertical in 12 units horizontal (200% slope), the nose end of all tiles shall be securely fastened.

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1--153 TABLE 15-D-2—CLAY OR CONCRETE ROOFING TILE APPLICATION INTERLOCKING TILE WITH PROJECTING ANCHOR LUGS—

MINIMUM ROOF SLOPE 4 UNITS VERTICAL IN 12 UNITS HORIZONTAL (33.3% Slope)

ROOF SLOPE 4 UNITS VERTICAL IN 12 UNITS HORIZONTAL (33.3% Slope) AND OVER

1. Deck requirements Spaced structural sheathing boards or solid roof sheathing.

2. Underlayment

In climate areas subject to wind-driven snow, roof ice or special wind regions as shown in Chapter 16, Figure 16-1.

Solid sheathing one layer of Type 30 felt lapped 2 inches (51 mm) horizontally and 6 inches (152 mm) vertically, except that extending from the eaves up the roof to line 24 inches (610 mm) inside the exterior wall line of the building, two layers of the underlayment shall be applied shingle fashion and solid cemented together with approved cementing material.

Other climates For spaced sheathing, approved reinforced membrane. For solid sheathing, one layer heavy-duty felt or Type 30 felt lapped 2 inches (51 mm) horizontally and 6 inches (152 mm) vertically.

3. Attachment¹

Type of fasteners Corrosion-resistant nails not less than No. 11 gage,⁵/16-inch (7.9 mm) head.

Fasteners shall comply with the requirements of Chapter 23, Division III, Part III.

Fasteners shall be long enough to penetrate into the battens²or sheathing³/₄inch (19 mm) or through the thickness of the sheathing, whichever is less. Attaching wire for clay or concrete tile shall not be smaller than 0.083 inch (2.11 mm) (No. 14 B.W. gage). Horizontal battens are required on solid sheathing for slopes 7 units vertical in 12 units horizontal (58.3%

slope) and over.²

Horizontal battens are required for slopes over 7 units vertical in 12 units horizontal (58.3% slope).² No. of fasteners with:

Spaced/solid sheathing with battens, or spaced sheathing³

Solid sheathing without battens³

Below 5 units vertical in 12 units horizontal (41.7% slope), fasteners not required. Five units vertical in 12 units horizontal (41.7% slope) to less than 12 units vertical in 12 units horizontal (100% slope), one fastener per tile every other row. Twelve units vertical in 12 units horizontal (100% slope) to 24 units vertical in 12 units horizontal (200% slope), one fastener every tile.⁴All perimeter tiles require one fastener.⁵Tiles with installed weight less than 9 pounds per square foot (4.4 kg/m²) require a minimum of one fastener per tile regardless of roof slope.

One fastener per tile.

4. Tile headlap 3-inch (76 mm) minimum.

5. Flashing Per Sections 1508.4 and 1509.

1In areas designated by the building official as being subject to repeated wind velocities in excess of 80 miles per hour (129 km/h), or where the roof height exceeds 40 feet (12 192 mm) above grade, all tiles shall be attached as set forth below:

1.1 The heads of all tiles shall be nailed.

1.2 The noses of all eave course tiles shall be fastened with a special clip.

1.3 All rake tiles shall be nailed with two nails.

1.4 The noses of all ridge, hip and rake tiles shall be set in a bead of approved roofer’s mastic.

2Battens shall not be less than 1-inch-by-2-inch (25 mm by 51 mm) nominal. Provisions shall be made for drainage beneath battens by a minimum of¹/8-inch (3.2 mm) risers at each nail or by 4-foot-long (1219 mm) battens with at least¹/2-inch (12.7 mm) separation between battens. Battens shall be fastened with approved fasteners spaced at not more than 24 inches (610 mm) on center.

3In snow areas, a minimum of two fasteners per tile are required, or battens and one fastener.

4Slopes over 24 units vertical in 12 units horizontal (200% slope), nose ends of all tiles must be securely fastened.

5Perimeter fastening areas include three tile courses but not less than 36 inches (914 mm) from either side of hips or ridges and edges of eaves and gable rakes.

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TABLE 15-E 1997 UNIFORM BUILDING CODE

1--154

TABLE 15-E—BUILT-UP ROOF-COVERING APPLICATION

MECHANICALLY FASTENED SYSTEMS ADHESIVELY FASTENED SYSTEMS

1. Deck conditions Decks shall be firm, broom-clean, smooth and dry. Insulated decks shall have wood insulation stops at all edges of the deck, unless an alternative suitable curbing is provided. Insulated decks with slopes greater than 2 units vertical in 12 units horizontal (16.7% slope) shall have wood insulation stops at not more than 8 feet (2438 mm) face to face. Wood nailers shall be provided where nailing is required for roofing plies.

Solid wood sheathing shall conform to Sections 2312.2 and

2320.12.9. Provide wood nailers where nailing is required for roofing

plies (see below).

2. Underlayment One layer of sheathing paper, Type 15 felt or other approved underlayment nailed sufficiently to hold in place, is required over board decks where openings between boards would allow bitumen to drip through. No underlayment requirements for plywood decks. Underlayment on other decks shall be in accordance with deck manufacturer’s recommendations.

Not required.

3. Base ply requirements

Over noninsulated decks Over approved decks, the base ply shall be nailed using not

less than one fastener for each 1¹/3square feet (0.124 m²). Decks shall be primed in accordance with the roofing manufacturer’s instructions. The base ply shall be solidly cemented or spot mopped as required by the type of deck material using adhesive application rates shown in Table 15-F.

4. Mechanical fasteners Fasteners shall be long enough to penetrate³/4inch (19 mm) into the sheathing or through the thickness of the sheathing, whichever is less. Built-up roofing nails for wood board decks shall be minimum No. 12 gage,⁷/16-inch (11.1 mm) head driven through tin caps or approved nails with integral caps.

For plywood, No. 11 gage ring-shank nails driven through tin caps or approved nails with integral caps shall be used. For gypsum, insulating concrete, cementitious wood fiber and other decks, fasteners recommended by the manufacturer shall be used.

When mechanical fasteners are required for attachment of roofing plies to wood nailers or insulation stops (see below), they shall be as required for wood board decks.

5. Vapor retarder

Over insulated decks A vapor retarder shall be installed where the average January temperature is below 45_F (7_C), or where excessive moisture conditions are anticipated within the building. It shall be applied as for a base ply.

6. Insulation When no vapor retarder is required, roof insulation shall be fastened in an approved manner. When a vapor retarder is required, roof insulation is to be solidly mopped to the vapor retarder using the adhesive application rate specified in Table 15-F. See manufacturer’s instructions for the attachment of insulation over steel decks.

When no vapor retarder is required, roof insulation shall be solid mopped to the deck using the adhesive application rate specified in Table 15-F. When a vapor retarder is required, roof insulation is to be solidly mopped to the vapor retarder, using the adhesive application rate specified in Table 15-F. See manufacturer’s installation instructions for attachment of insulation over steel decks.

7. Roofing plies Successive layers shall be solidly cemented together and to the base ply or the insulation using the adhesive rates shown in Table 15-F. On slopes greater than 1 unit vertical in 12 units horizontal (8.3% slope) for aggregate-surfaced, or 2 units vertical in 12 units horizontal (16.7% slope) for smooth-surfaced or cap sheet surfaced roofs, mechanical fasteners are required. Roofing plies shall be blind-nailed to the deck, wood nailers or wood insulation stops in accordance with the roofing manufacturer’s recommendations. On slopes exceeding 3 units vertical in 12 units horizontal (25% slope), plies shall be laid parallel to the slope of the deck (strapping method).

8. Cementing materials See Table 15-G.

9. Curbs and walls Suitable cant strips shall be used at all vertical intersections. Adequate attachment shall be provided for both base flashing and counterflashing on all vertical surfaces. Reglets shall be provided in wall or parapets receiving metal counterflashing.

10. Surfacing Mineral aggregate surfaced roofs shall comply with the requirements of UBC Standard 15-1 and Table 15-F. Cap sheets shall be cemented to the roofing plies as set forth in Table 15-F.

In document UBC VOL 1 (Page 159-167)