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Minnesota Legislature

Office of the Revisor of Statutes

1309.0302 SECTION R302, FIRE-RESISTANT CONSTRUCTION.

Subpart 1.

IRC section R302.2, Townhouses.

Section R302.2 is amended to read as follows:

R302.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of section R302.1 for exterior walls.

Exception: A common 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263 is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be installed in accordance with Minnesota Rules, chapter 1315. Penetrations of electrical outlet boxes shall be in accordance with section R302.4.

R302.2.1 Continuity. The fire-resistance-rated wall assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, roof deck, or roof slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures. The separation shall extend through enclosed soffits, overhangs, and similar projections.

R302.2.2 Parapets. Parapets constructed in accordance with section R302.2.3 shall be constructed for townhouses as an extension of exterior walls or common walls in accordance with the following:

1. where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces; or

2. where roof surfaces adjacent to the wall or walls are at different elevations, and the higher roof is not more than 30 inches (762 mm) above the lower roof, the parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.

Exception: A parapet is not required in the two cases above when the roof is covered with a minimum class C roof covering, and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) type X gypsum board is installed directly beneath the roof decking or sheathing, supported by a minimum of nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a minimum distance of 4 feet (1219 mm) on each side of the wall or walls and there are no openings or penetrations in the roof within 4 feet (1219 mm) of the common walls.

3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall have not less than a 1-hour fire-resistance rating. The wall shall be rated for exposure from both sides.

TABLE R302.1(1) EXTERIOR WALLS

EXTERIOR WALL ELEMENT MINIMUM FIRE-RESISTANCE RATING MINIMUM FIRE SEPARATION DISTANCE
Walls
Fire-resistance-rated 1-hour - tested in accordance with ASTM E 119 or UL 263 with exposure from both sides < 5 feet
Not fire-resistance-rated 0 hours ≥ 5 feet
Projections
Fire-resistance-rated 1-hour on the undersidea ≥ 2 feet to < 5 feet
Not fire-resistance-rated 0 hours ≥ 5 feet
Openings in walls
Not allowed N/A < 3 feet
25% Maximum of Wall Area 0 hours 3 feet
Unlimited 0 hours 5 feet
Penetrations
All Comply with section R302.4 < 5 feet
None required 5 feet

For SI: 1 foot = 304.8 mm

N/A = Not Applicable

a 1-hour on the underside equates to one layer of 5/8-inch type X gypsum sheathing. Openings are not allowed.

TABLE R302.1(2) EXTERIOR WALLS - DWELLINGS WITH FIRE SPRINKLERS

EXTERIOR WALL ELEMENT MINIMUM FIRE-RESISTANCE RATING MINIMUM FIRE SEPARATION DISTANCE
Walls
Fire-resistance-rated 1-hour - tested in accordance with ASTM E 119 or UL 263 with exposure from the outside 0 feet
Not fire-resistance-rated 0 hours 3 feet
Projections
Fire-resistance-rated 1-hour on the undersidea 2 feet
Not fire-resistance-rated 0 hours 3 feet
Openings in walls
Not allowed N/A < 3 feet
Unlimited 0 hours 3 feet
Penetrations
All Comply with section R302.4 < 3 feet
None required 3 feet

For SI: 1 foot = 304.8 mm

N/A = Not Applicable

a 1-hour on the underside equates to one layer of 5/8-inch type X gypsum sheathing. Openings are not allowed.

R302.2.3 Parapet construction. Parapets shall have the same fire-resistance rating as that required for the supporting wall or walls. On any side adjacent to a roof surface, the parapet shall have noncombustible faces for the uppermost 18 inches (457 mm), to include counterflashing and coping materials. Where the roof slopes toward a parapet at slopes greater than 2 units vertical in 12 units horizontal (16.7 percent slope), the parapet shall extend to the same height as any portion of the roof within a distance of 3 feet (914 mm), but in no case shall the height be less than 30 inches (762 mm).

R302.2.4 Structural independence. Each individual townhouse shall be structurally independent.

Exceptions:

1. Foundations supporting exterior walls or common walls.

2. Structural roof and wall sheathing from each unit may fasten to the common wall framing.

3. Nonstructural wall and roof coverings.

4. Flashing at termination of roof covering over common wall.

5. Townhouses separated by a common 1-hour fire-resistance-rated wall as provided in section R302.2.

R302.2.5 Sound transmission. Townhouses constructed in accordance with section R302.2 shall comply with the sound transmission requirements of Appendix K.

Subp. 2.

IRC section R302.3, Two-family dwellings.

Section 302.3 is amended by adding a subsection to the end of the section to read as follows:

R302.3.2 Sound transmission. Two-family dwellings constructed in accordance with section R302.3 shall comply with the sound transmission requirements of Appendix K.

Subp. 3.

IRC section R302.5.1, Opening protection.

Section 302.5.1 is amended to read as follows:

R302.5.1 Opening protection. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 1-3/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 1-3/8 inches (35 mm) thick, or 20-minute fire-rated doors.

Subp. 4.

IRC section R302.6.

Section R302.6 and Table R302.6 are amended to read as follows:

R302.6 Dwelling/garage fire separation. The garage shall be separated as required by Table R302.6. Openings in garage walls shall comply with section R302.5.

TABLE R302.6 DWELLING/GARAGE SEPARATION

SEPARATION MATERIAL
From the residence and attics Not less than 1/2-inch gypsum board or equivalent applied to the garage side. Vertical separation between the garage and the residence attic shall extend to the roof sheathing or rafter blocking.
From all habitable rooms above the garage Not less than 5/8-inch type X gypsum board or equivalent.
Structural members supporting floor/ceiling assemblies or garage ceiling used for separation required by this section Not less than 1/2-inch gypsum board or equivalent applied to the garage side of structural members supporting the floor/ceiling assemblies or garage ceiling. Structural members include, but are not limited to: walls, columns, beams, girders, and trusses.
Garages located less than 3 feet from a dwelling unit on the same lot Not less than 1/2-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area. This provision does not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.

Statutory Authority:

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

History:

32 SR 12; L 2007 c 140 art 4 s 61; art 13 s 4; 39 SR 91

Published Electronically:

January 26, 2015