2308.4.1.1 Allowable girder spans.
BC § 2308.4.1.1
The allowable spans of girders that are fabricated of dimension lumber shall not exceed the values set forth in Table 2308.4.1.1(1) or 2308.4.1.1(2). Table 2308.4.1.1(1)Header and Girder Spans a, b, c, d for Exterior Bearing Walls(Maximum spans for Douglas Fir-Larch, Hem-Fir, Southern Pine and Spruce-Pine-Fir and required number of jack studs) Headers and Girders SupportingSizeBuilding width e (feet)122436Span gNJ fSpan gNJ fSpan gNJ fHeaders and Girders SupportingSizeBuilding width e (feet)122436Span gNJ fSpan gNJ fSpan gNJ fRoof and ceiling2-2 x 44-013-112-712-2 x 66-014-713-1012-2 x 87-715-914-1022-2 x 109-016-1025-922-2 x 1210-728-126-1023-2 x 89-517-316-113-2 x 1011-318-717-323-2 x 1213-2110-128-624-2 x 810-1118-417-014-2 x 1012-1119-1118-414-2 x 1215-3111-819-102Roof, ceiling and one center-bearing floor2-2 x 43-312-612-212-2 x 64-1013-913-322-2 x 86-114-1024-122-2 x 107-325-824-1022-2 x 128-626-825-823-2 x 87-816-015-123-2 x 109-117-226-123-2 x 1210-828-527-224-2 x 88-1016-1115-1114-2 x 1010-618-327-024-2 x 1212-419-828-32Roof, ceiling and one clear span floor2-2 x 42-1112-311-1012-2 x 64-413-422-1022-2 x 85-624-323-722-2 x 106-725-024-222-2 x 127-925-1124-1133-2 x 86-1115-324-523-2 x 108-326-325-323-2 x 129-827-526-224-2 x 88-016-115-124-2 x 109-617-326-124-2 x 1211-228-627-22Roof, ceiling and two center-bearing floors2-2 x 42-812-111-912-2 x 64-013-222-822-2 x 85-024-023-522-2 x 106-024-924-022-2 x 127-025-724-933-2 x 86-415-024-323-2 x 107-625-1125-123-2 x 128-1027-025-1124-2 x 87-315-914-1124-2 x 108-816-1025-1024-2 x 1210-228-126-102Roof, ceiling and two clear span floors2-2 x 42-311-811-412-2 x 63-412-622-222-2 x 84-323-322-822-2 x 105-023-1023-232-2 x 125-1124-633-933-2 x 85-314-023-523-2 x 106-324-924-023-2 x 127-525-824-934-2 x 86-114-823-1124-2 x 107-325-624-824-2 x 128-626-625-62 For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa. a. Spans are given in feet and inches. b. Spans are based on minimum design properties for No. 2 grade lumber of Douglas Fir-Larch, Hem-Fir, Southern Pine and Spruce-Pine Fir. c. Use for cases in which the roof live load is equal to or less than 20 psf. d. Values are for 30 psf ground snow load. e. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated. f. NJ = Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header. g. Spans are calculated assuming the top of the header or girder is laterally braced by perpendicular framing. Where the top of the header or girder is not laterally braced (for example, cripple studs bearing on the header), tabulated spans for headers consisting of 2 × 8, 2 × 10, or 2 × 12 sizes shall be multiplied by 0.70 or the header or girder shall be designed. Table 2308.4.1.1(2)Header and Girder Spans a, b for Interior Bearing Walls(Maximum spans for Douglas Fir-Larch, Hem-Fir, Southern Pine and Spruce-Pine-Fir and required number of jack studs) Headers and Girders SupportingSizeBuilding width c (feet)122436Span eNJ dSpan eNJ dSpan eNJ dHeaders and Girders SupportingSizeBuilding width c (feet)122436Span eNJ dSpan eNJ dSpan eNJ dOne floor only2-2 x 44-112-1012-412-2 x 66-114-413-612-2 x 87-915-514-522-2 x 109-216-625-322-2 x 1210-917-726-323-2 x 89-816-1015-713-2 x 1011-518-116-723-2 x 1213-619-627-924-2 x 811-217-1116-514-2 x 1013-319-417-814-2 x 1215-7111-019-02Two floors2-2 x 42-711-1111-712-2 x 63-1112-1122-522-2 x 85-013-823-122-2 x 105-1124-423-722-2 x 126-1125-224-333-2 x 86-314-723-1023-2 x 107-515-624-623-2 x 128-826-525-424-2 x 87-215-414-524-2 x 108-616-425-324-2 x 1210-117-526-22 For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa. a. Spans are given in feet and inches. b. Spans are based on minimum design properties for No. 2 grade lumber of Douglas Fir-Larch, Hem-Fir, Southern Pine and Spruce-Pine Fir. c. Building width is measured perpendicular to the ridge. For widths between those shown, spans are permitted to be interpolated. d. NJ = Number of jack studs required to support each end. Where the number of required jack studs equals one, the header is permitted to be supported by an approved framing anchor attached to the full-height wall stud and to the header. e. Spans are calculated assuming the top of the header or girder is laterally braced by perpendicular framing. Where the top of the header or girder is not laterally braced (for example, cripple studs bearing on the header), tabulated spans for headers consisting of 2 × 8, 2 × 10, or 2 × 12 sizes shall be multiplied by 0.70 or the header or girder shall be designed.
