Roof Diaphragm Aspect Ratio

2306 2 4 gypsum board diaphragm ceilings.

Roof diaphragm aspect ratio.

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. Jump to full code chapter. Diaphragm aspect ratio is ok. 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.

Twelve large diaphragm models were created to investigate the influences of various modeling and. Double diagonally sheathed lumber diaphragms shall be designed and constructed in accordance with af pa sdpws. Similar changes to 2306 3 for shear walls. 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.

Size and shape of diaphragms shall be limited as set forth in table 2305 2 3. Gypsum board diaphragm ceilings shall be in accordance with section 2508 5. There is a discussion going between the engineers in my office about the acceptibility of a 4 3 1 roof diaphragm. 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. But i can t find any similar limit for metal deck. Analyses were performed for both loads applied in the longitudinal and transverse directions i e. Roof systems 3 1 3 4 lumber rafters.

Roof diaphragm aspect ratio table 3 16a1 l. 2305 2 3 diaphragm aspect ratios. 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. Min 12 7 and l.

Aspect ratios of 2 1 and 1 2. The sdi diaphragm design manual third edition is an excellent design reference every engineer should utilize if designing with steel deck diaphragms. The maximum unit shear on the wall diaphragm is also equal to the roof reaction r divided by b. The maximum roof diaphragm moment m equals ww wl x l2 8.

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. Behavior of a case study all wood panelized 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. The corresponding diaphragm chord forces are therefore equal to m divided by the diaphragm depth b.