Roof Diaphragm Aspect Ratio

The dimensions of the case study diaphragm were 192 ft x 96 ft.

Roof diaphragm aspect ratio.

2010 building code of ny 23 wood 2305 general design requirements for lateral force resisting systems 2305 2 design of wood diaphragms 2305 2 3 diaphragm aspect ratios. Roof systems 3 1 3 4 lumber rafters. 2305 2 3 diaphragm aspect ratios. The manual includes pertinent design information considerations fastener information deck shear capacity tables and a plethora of highly relevant design examples stepping you through all the intricate details and covering nearly any.

2306 2 4 gypsum board diaphragm ceilings. Jump to full code chapter. I know for plywood diaphragms the codes limit it to 4 1 aspect ratio. 2 since flexibility ratio increases with increase in aspect ratio of building we can say that flexibility of diaphragm increases with increase in aspect ratio.

Wood structural panel unblocked 3 1 wood structural panel blocked 4 1 single layer straight lumber sheathing 2 1 single layer diagonal lumber sheathing 3 1 double layer diagonal lumber. Behavior of a case study all wood panelized roof diaphragm. Roof diaphragm aspect ratio table 3 16a1 l. Gypsum board diaphragm ceilings shall be in accordance with section 2508 5.

Similar changes to 2306 3 for shear walls. Analyses were performed for both loads applied in the longitudinal and transverse directions i e. Rafter span horizontal projection 26 16 rafter spacing 24 16 eave overhang length lesser of 2 or rafter length 3 2 rake overhang length lesser of 2 or outlooker length 2 2 roof slope 1 5 12 12 7 12 roof diaphragms. 3 amongst all the models only four storey building with 1 4 aspect ratio has flexibility ratio greater than 1 5 so it s.

The maximum roof diaphragm moment m equals ww wl x l2 8. There is a discussion going between the engineers in my office about the acceptibility of a 4 3 1 roof diaphragm. Diaphragm aspect ratios sdpws table 4 2 4 type maximum length width ratio for an 84 x 34 diaphragm the aspect ratio is 2 5 3. Min 12 7 and l.

The sdi diaphragm design manual third edition is an excellent design reference every engineer should utilize if designing with steel deck diaphragms. Diaphragm aspect ratio is ok. 2306 2 3 double diagonally sheathed lumber diaphragms. Aspect ratios of 2 1 and 1 2.

Wood diaphragm chords aspect ratios hokie66 structural 2 jan 11 14 56 when it gets too complicated to brace at the roof level brace at the ceiling level. The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b. Size and shape of diaphragms shall be limited as set forth in table 2305 2 3. But i can t find any similar limit for metal deck.