Roof Diaphragm Aspect Ratio

The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b.

Roof diaphragm aspect ratio.

2306 2 4 gypsum board diaphragm ceilings. 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. Min 12 7 and l. The dimensions of the case study diaphragm were 192 ft x 96 ft.

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. 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. Double diagonally sheathed lumber diaphragms shall be designed and constructed in accordance with af pa sdpws.

Analyses were performed for both loads applied in the longitudinal and transverse directions i e. I know for plywood diaphragms the codes limit it to 4 1 aspect ratio. The maximum roof diaphragm moment m equals ww wl x l2 8. But i can t find any similar limit for metal deck.

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. 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. Diaphragm aspect ratio is ok. 2306 2 3 double diagonally sheathed lumber diaphragms.

Similar changes to 2306 3 for shear walls. Roof diaphragm aspect ratio table 3 16a1 l. Gypsum board diaphragm ceilings shall be in accordance with section 2508 5. Roof systems 3 1 3 4 lumber rafters.

The sdi diaphragm design manual third edition is an excellent design reference every engineer should utilize if designing with steel deck diaphragms. Jump to full code chapter. Twelve large diaphragm models were created to investigate the influences of various modeling and. 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.

There is a discussion going between the engineers in my office about the acceptibility of a 4 3 1 roof diaphragm. 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. Behavior of a case study all wood panelized roof diaphragm. 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.