2000-P02858 - deck - Laserfiche WebLink

Home Browse Search

.- � ��rooD DECKS - SA(�PLE CaLCULATIOr�s FOR USIr�G THE SPAN TABLE � , a I Case I Solution: Rerer to table for joist and beam sizes . -►j Example: a = 12' � Post Spacing = 8' Refer to the span table. Joist size may be either. 2x8` s 12" O,C. or 2x10's 16" O.C. Beam size may be either 3-2x8'x or ! 2-2x10's. Case II Solution: Use."a" for joist size and "a" + "b" to � deternine beam size (7he length oT "b" is restricted by :� a �,� b i both the 7ength of "a" and the size of the joists) . I � Example: a = 8' , b = 2' , Post Spacing = 10' � Find the joist size required by looking under 8' on the ( table. Joist lenath is indicated as 2x6' s 76" O.C. or � 2x8's 2�" O.C. For si zing �t�e beam, use a joist i ength o; E 1p' (g' + 2` = 10' ) and a pos� spacing o` 10' . The table . indicates that 4-2x8' s or 3-2x10's are required for the bezr�. Case III Solution: Use "a" or "b" , whichever is oreater, to determine joist size. Use "a" + •"b" to determine the size o� Beam No. 1 and use joist length "b" to determine the a ` , size or" Beam_No. 2. _ _ •� ° � t � cxample: a 6' , b 7 ' , Post Spacing 9 ' , . ihe joist length (7 ' ) is dete ,�,ined by the longest span jois� ("b") . ihe table indicates that 2x6's 16" O.C, or 2x8 ' s 24" Q.C. zre required for a 7 ' span. For Beam No. 1 , use ;oist length 3�� BE°� 2 of 13 ' (6` + 7' = 13 ' ) and pos� spacing of 9' . The table � indicates that 3-2x10's or 2-2x12's are required for Beam No. l . ' For Beam No. 2 use joist length of 1' with a �post spaE�ng of 9 ' .� The table indicates that 4-2x6's or 3-Zx8's are required for Beam No. 2. -- • �dSe ?�l SO�Ut1011: �52 ��d�� 01' ��b�� , whichever 1S greater, t0 d2:ermine JO15L S1Ze. �SE ��c�� + ��b`� t0 determine t�12 S1Z� of Beam Ho. 1 and "h" + "c" to determine the size of Beam ��o. 2. � (Tne length of "c" is restricted by both tt�e length of "b" and the size of the joist) . � a b c � cxample: a = 7` , b = 8' , c = Z' , Post Spacing = 12 ' - ihe longest joist span is 3 '; therefore, the table indicates that 2x6`s 16" O.C. or 2x8's 2�" O.C. are required. For No. 1 No. 2 Beam No. l , use jois� length oT 15' (7 ' + 8' = 15'} and 3eam Beam post spacing of 12' . The table indicates that 3-2x12 's are required for Beam No. l . For Beam No. 2, use joist length of . � ]0' (8' + 2' = 10' ) and post spacing of 12' . The table indicates that 3-Zx10's or 3-2x12's ar.e required. for � � _ Beam No. 2. • � � . NOTES: Post size must be adequate to provide full �be�m bearing, ie. ,��one-member' and two-menber beams must he placed on a 4x4 post, three-member beams must be � . placed on 4x6 or 6x6 posts, and four-member beams must be placed on Sx8 posts. Most of the boxes in this tabl'e contain two optional means of .support. Wood.. manbers may be .increased above those indicated in the table, but in no event may lesser members be used.