Minnesota Administrative Rules

1309.0602 SECTION R602, WOOD WALL FRAMING.

Subpart 1.

Table R602.3.1.

IRC Table R602.3.1 is amended to read as follows:

TABLE R602.3.1

MAXIMUM ALLOWABLE LENGTH OF WOOD WALL STUDS EXPOSED TO

WIND SPEEDS OF 90 MPH OR LESS^{b,c,d,e,f,g,h,i}

Where conditions are not within the parameters

of footnotes b, c, d, e, f, g, h, and i,

design is required.

ROOF SPANS UP TO 22' SUPPORTING A ROOF ONLY
Maximum Wall Height (feet)	Exposure Categoryh,i	On-Center Spacing (inches)
		24	16	12	8
		_
10	B	2x6	2x4	2x4	2x4
	C	2x6	2x6	2x4	2x4
12	B	2x6	2x6	2x4	2x4
	C	2x6	2x6	2x6	2x4
14	B	2x6	2x6	2x6	2x4
	C	2x6	2x6	2x6	2x6
16	B	2x8	2x6	2x6	2x6
	C	2x8	2x6	2x6	2x6
18	B	2x8	2x8	2x6	2x6
	C	2x8	2x8	2x6	2x6
20	B	2x8	2x8	2x8	2x6
	C	NAa	2x8	2x8	2x6
24	B	NAa	2x8	2x8	2x8
	C	NAa	NAa	2x8	2x8

_

ROOF SPANS GREATER THAN 22' AND UP TO 26' SUPPORTING A ROOF ONLY
Maximum Wall Height (feet)	Exposure Categoryh,i	On-Center Spacing (inches)
		24	16	12	8
		_
10	B	2x6	2x6	2x4	2x4
	C	2x6	2x6	2x6	2x4
12	B	2x6	2x6	2x6	2x4
	C	2x8	2x6	2x6	2x6
14	B	2x6	2x6	2x6	2x6
	C	2x8	2x8	2x6	2x6
16	B	2x8	2x6	2x6	2x6
	C	2x8	2x8	2x6	2x6
18	B	2x8	2x8	2x6	2x6
	C	NAa	2x8	2x8	2x6
20	B	NAa	2x8	2x8	2x6
	C	NAa	NAa	2x8	2x8
24	B	NAa	NAa	2x8	2x8
	C	NAa	NAa	NAa	2x8

_

ROOF SPANS GREATER THAN 26' AND UP TO 30' SUPPORTING A ROOF ONLY
Maximum Wall Height (feet)	Exposure Categoryh,i	On-Center Spacing (inches)
		24	16	12	8
		_
10	B	2x6	2x6	2x4	2x4
	C	2x6	2x6	2x6	2x4
12	B	2x6	2x6	2x6	2x4
	C	2x8	2x6	2x6	2x6
14	B	2x8	2x6	2x6	2x6
	C	2x8	2x8	2x6	2x6
16	B	2x8	2x6	2x6	2x6
	C	2x8	2x8	2x8	2x6
18	B	2x8	2x8	2x6	2x6
	C	NAa	2x8	2x8	2x8
20	B	NAa	2x8	2x8	2x6
	C	NAa	NAa	2x8	2x8
24	B	NAa	NAa	2x8	2x8
	C	NAa	NAa	NAa	2x8

_

ROOF SPANS GREATER THAN 30' AND UP TO 34' SUPPORTING A ROOF ONLY
Maximum Wall Height (feet)	Exposure Categoryh,i	On-Center Spacing (inches)
		24	16	12	8
		_
10	B	2x6	2x6	2x4	2x4
	C	2x6	2x6	2x6	2x4
12	B	2x6	2x6	2x6	2x4
	C	2x8	2x6	2x6	2x6
14	B	2x8	2x6	2x6	2x6
	C	2x8	2x8	2x6	2x6
16	B	2x8	2x8	2x6	2x6
	C	NAa	2x8	2x8	2x6
18	B	2x8	2x8	2x6	2x6
	C	NAa	NAa	2x8	2x8
20	B	NAa	2x8	2x8	2x6
	C	NAa	NAa	2x8	2x8
24	B	NAa	NAa	2x8	2x8
	C	NAa	NAa	NAa	2x8

a. Design required.

b. Applicability of these tables assumes the following: SPF#2 or better, Ground snow = 60 psf, Roof snow = 42 psf, Component and Cladding Zone 4 - 50 square feet (Exposure B = 14.3 psf, Exposure C = 18.4 psf), eaves not greater than 2.0 feet in dimension.

c. The exterior of the wall shall be continuously sheathed in accordance with one of the methods (2-8) listed in Section R602.10.3.

d. Studs shall be continuous full height.

e. Full depth blocking is required at 10-foot spacing maximum.

f. Utility, standard, stud, and No. 3 grade lumber of any species are not permitted.

g. This table is based on a maximum allowable deflection limit of L/120.

h. Exposure B-Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Exposure B shall be assumed unless the site meets the definition of another type exposure.

i. Exposure C - Open terrain with scattered obstructions, including surface undulations or other irregularities, having heights generally less than 30 feet extending more than 1,500 feet from the building site in any quadrant. This category includes flat open country, grasslands, and shorelines in hurricane prone regions. Exposure C shall also apply to any building located within Exposure B type terrain where the building is directly adjacent to open areas of Exposure C type terrain in any quadrant for a distance of more than 600 feet.

Statutory Authority:

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

History:

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

Published Electronically:

February 23, 2009