Minn. R. agency 151, ch. 1346, MINNESOTA MECHANICAL CODE, pt. 1346.0306

Current through Register Vol. 49, No. 20, November 12, 2024

Part 1346.0306 - SECTION 306 ACCESS AND SERVICE SPACE

Subpart 1.Section 306.5, Mechanical equipment and appliances on roofs or elevated 4.14 structures.

IMC section 306.5 is amended to read as follows:

306.5Mechanical equipment and appliances on roofs or elevated structures. Where mechanical equipment or appliances requiring periodic inspection, service, or maintenance are installed on roofs or elevated structures, a permanent stair shall be provided for access.

Exception: A portable ladder may be used for dwellings, replacement equipment and appliances, on existing buildings, and exterior roof access points not exceeding 16 feet (4.9 m) above grade, unless the building official determines that the unique shape of the roof does not allow safe access with a portable ladder.

The permanent stair shall, at a minimum, meet the following:

1. The stair shall be installed at an angle of not more than 60 degrees measured from the horizontal plane.

2. The stair shall have flat treads at least 6 inches (152 mm) deep and a clear width of at least 18 inches (457 mm) with equally spaced risers at least 10.5 inches (267 mm) high and not exceeding 14 inches (356 mm).

3. The stair shall have intermediate landings not exceeding 18 feet (5.5 m) vertically.

4. Continuous handrails shall be installed on both sides of the stair.

5. Interior stairs shall terminate at the under side of the roof at a hatch or scuttle of at least 8 square feet (0.74 m²) with a minimum dimension of 20 inches (508 mm).

6. When a roof access hatch or scuttle is located within 10 feet (3.0 m) of a roof edge, a guard shall be installed in accordance with IMC section 304.11.

7. Exterior stairs shall terminate at the roof access point or at a level landing of at least 8 square feet (0.74 m²) with a minimum dimension of 20 inches (508 mm). The landing shall have a guard installed in accordance with IMC section 304.11.

306.5.1Sloped roofs. Where appliances, equipment, fans, or components that require service are installed on a roof having a slope of 3 units vertical in 12 units horizontal (25-percent slope) or greater and having an edge more than 30 inches (762 mm) above grade at such edge, a level platform shall be provided on each side of the appliance to which access is required for service, repair, or maintenance. The platform shall be at least 30 inches (762 mm) in any dimension and shall be provided with guards. The guards shall extend at least 42 inches (1067 mm) above the platform, shall be constructed so as to prevent the passage of a 21-inch-diameter (533 mm) sphere and shall comply with the loading requirements for guards specified in Minnesota Rules, chapter 1305.

306.5.2Electrical requirements. A receptacle outlet shall be provided at or near the equipment or appliance location in accordance with the Minnesota Electrical Code.

306.5.3Permanent ladders. Where a change in roof elevation greater than 30 inches (762 mm) but not exceeding 16 feet (4.9 m) exists, a permanent ladder shall be provided. The ladder shall be vertical. The ladder must, at a minimum, meet the following:

1. Width shall be at least 16 inches (406 mm).

2. Rung spacing shall be a maximum of 14 inches (356 mm).

3. Toe space shall be at least 6 inches (152 mm).

4. Side railings shall extend at least 30 inches (762 mm) above the roof or parapet wall.

Subp. 2. [Renumbered subp. 1b]

Subp. 3. [Renumbered subp. 1b]

Minn. R. agency 151, ch. 1346, MINNESOTA MECHANICAL CODE, pt. 1346.0306

29 SR 299; L 2007 c 140 art 4 s 61; art 13 s 4; 34 SR 537 29 SR 299; L 2007 c 140 art 4 s 61; art 13 s 4; 34 SR 537; 39 SR 690; 44 SR 1085

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326B.02; 326B.101; 326B.106; 326B.13