Wind Shear Wall Roof Diaphragm

The fastening requirements are those required to resist uplift forces from wind pressures and shear forces.

Wind shear wall roof diaphragm.

The lateral force is transferred through the web of the diaphragm to the walls which act as supports for the diaphragm. Function as a diaphragm to transfer lateral loads to the building s shear walls. Wood frame structure shown lateral wind load 30 psf 2x rafters and studs find. These construction systems can be used when designing a building for lateral loads such as those generated by wind or earthquakes.

Illustrated in figure 1 is a diaphragm with an lfrs consisting of structural walls and collector elements. A shear wall however is a vertical cantilevered diaphragm. The diaphragm forces tend to be transferred to the vertical resisting elements. Unblocked diaphragm capacity capacities in sdpws are nominal values.

Because the wall on the left does not extend the full depth of the diaphragm collector elements are needed to collect the shear from the diaphragm and to transfer it. Side wall carries load to roof diaphragm at top and to foundation at bottom roof horizontal diaphragm carries load to end walls end wall vertical diaphragm or shear wall carries load to foundation v lb per lin ft of diaphragm width w lb per lin ft of wall f t lb c vh h 2 wl 2b wind load lb per sq ft figure 1. Design roof diaphragm sheathing and shear walls on short side. The term diaphragm is usually applied to roofs and floors.

Use apa sheathing tables in x305 peter von buelow university of michigan tcaup slide 19 of 28. Diaphragm and shear wall perimeters. The ibc irc wfcm and icc 600 all contain prescriptive requirements for fastening roof sheathing. Structures using wood frame shear walls or wood frame diaphragms to resist wind seismic or other lateral loads shall be designed and constructed in accordance with af pa sdpws and the applicable provisions of sections 2305 2306 and 2307.

Diaphragm and shear wall example given. Walls for simplicity sake. A diaphragm is a flat structural unit acting like a deep thin beam. Wind load diaphragm sheathing floor roof framing parallel to walls add blocking floor joist blocking.

When looking at the wind tributary to a diaphragm in order to calculate the shear wall capacities i normally resolve the wind forces to the roof and half the wall height single story four ext.