2016-00625 - attached deck - Laserfiche WebLink

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Joist span � Based on No.2 or better wood grades. Design Load =40#LL+ 10#DL, Deflection= L/360 ' . . - . . 12"OC 16"OC 24"OC 12"OC 16"OC 24"OC 12"OC 16"OC 24"OC 2x6 10-0 9-1 7-11 10-3 9-4 7-7 9-2 8-4 7-3 2x8 13-2 12-0 10-6 13- 11-10 9-8 12-1 11-0 9-7 -- -----------------------------------------------��----- ------- �� . .......... -------------�� ------------ � -...---.................---------- � --- -----------�------.....-�----------------..... �� ............ 2x10 16-10 15-3 13-4 16-2 14-0 11-5 15-5 14-0 12-3 2x12 20-6 18-7 16-3 19-1 16-6 13-6 18-9 17-0 14-11 Sample calculations for using joist span, beam size and footing size tables Case I solution: Refer to tables for joist,beam and footing size requirements. a Example:a = 12 feet;Post spacing = 8 feet ,�'�� n' : Use the joist span table to find the acceptable joist sizes for a 12 foot span, 2x8s at 12 inches O.C., 2x10s at 16 inches O.C.or 2x12s at 24 inches O.C. Use the Beam and footing sizes table and find the 8 foot post spacing column. �3= With a 12 foot deck span, the beam may be either two 2x8s or two 2x10s, � depending on wood used. Depending on the type of soil, the footing diameter at the base must be a minimum of 12 inches, 10 inches or 9 inches for the corner post and 17 inches, 14 inches or 12 inches for all intermediate posts. Case II solution: Use "a"to determine joist size and "a"+ "2b"to determine beam and footing sizes. The length of"b"is restricted by both the length of"a"and the size of the joists. Example:a = 8 feet, b = 2 feet, Post spacing = 10 feet a ; b � Refer to the joist span table.For an 8 foot joist span, either 2x8s at 24 inches O.C. or ��_. �p�,�.�,��,�� 2x6s at 16 inches O.0 are acceptable. For sizing the beam, use a joist length of 12 feet (8 feet + 4 feet) and a post �� spacing of 10 feet. The beam and footing sizes table indicates that the beam may be either two 2x10s or two 2x12s, depending on wood used. Depending on the _ �= type of soil, the footing diameter at the base must be a minimum of 15 inches, 12 inches or 11 inches for the corner post and 20 inches, 17 inches or 15 inches for all intermediate posts. Note that because of the 2 foot cantilever all footing sizes were increased by 1 inches as required by footnote 2 at the end of the table. Caselllsolution: Use "a"or "b;'whichever is greater, to determine joist size. Use "a"+ "b"to determine the size of Beam 1 and the post footing size for the posts supporting eeam 1.Use joist length "b"to determine both the size of Beam 2 and the post footing size forthe posts supporting Beam 2. .a.yi b � Example:a = 6 feet, b = 7 feet, Post spacing =9 feet �t� a �°�e '' Joist size is determined by using the longest span joist (7 feet). The joist span Beam 1 � Beam 2 —+ table indicates that 2x6s at 24"O.C.would be adequate for this span. '' For Beam 1 and footings, use a joist length of 13 feet (6 feet + 7 feet) and a post spacing of 9 feet. The beam and footing sizes table indicates that the beam may � be two 2x10s or two 2x12s, depending on the wood used. Depending on the type of soil, the footing diameters for Beam 1 posts shall be 13 inches, 11 inches or 9 inches for the corner (outside) post and 19 inches, 15 inches or 13 inches for all intermediate posts. For Beam 2 and footings use a joist length of 7 feet and post spacing of 9 feet. The beam may be two 2x8s or two 2x10s, depending on wood used. Depending on the type of soil, the footing diameters for Beam 2 shall be 10 inches, 8 inches or 7 inches for the corner posts, and 14 inches, 11 inches or 10 inches for all intermediate posts.