Minnesota Administrative Rules

1305.0420 SECTION 420, GROUP I-1, R-1, R-2, R-3.

Subpart 1.

IBC section 420.1.

IBC section 420.1 is amended to read as follows:

420.1 General. Occupancies in Groups I-1, R-1, R-2, and R-3 shall comply with the provisions of sections 420.1 through 420.6 and other applicable provisions of this code.

(Sections 420.2 to 420.5 remain unchanged.)

Subp. 2.

IBC section 420.6.

IBC section 420 is amended by adding a subsection to read as follows:

420.6 Fire protection of floors. Floor assemblies, not required elsewhere in this code to be fire-resistance rated, shall be provided with 1/2-inch (12.7 mm) gypsum wallboard membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member.

Exceptions:

1. Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with NFPA 13D, or other approved equivalent sprinkler system.

2. Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.

3. Portions of the floor assemblies in Group R-3 can be unprotected when complying with the following:

a. The aggregate area of the unprotected portions shall not exceed 80 square feet per story; and

b. Fire blocking in accordance with Section 717.2 shall be installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly.

4. Wood floor assemblies in Group R-3 occupancies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.

Statutory Authority:

MS s 326B.02; 326B.101; 326B.106

History:

39 SR 1605

Published Electronically:

June 19, 2015