So the plan checker is asking for diaphragm deflection calcs on the metal strap horizontal strap brace... which I could gather for a cantilever diaphragm you would use delta = S * ( a / Ga ) with Ga being the apparent shear stiffness. Anybody use a different method? I am not sure how to get...
Thanks for the post XR250. Is the reason for using a wood brace rather than a metal strap because of exposure? Seems like it would be easier to get the necessary end nailing with a strap in that situation..
I'm curious about the type of horizontal bracing you would prescribe for a wood deck like I mentioned above XR250? Would these be diagonals in the plane of the diaphragm? Diagonal straps? Sounds like R=4 would be an appropriate basis for seismic load.
As for knee braces and taking a...
The 1991 UCB shows a R value of 4 for Bearg wall systems, 8 for building frame systems with concentrically braced frames... one of the reasons 1 or 1.5 was an eyebrow raiser at first.
Found this relevant FEMA paper looking around...
I am designing a 10x36 covered residential deck attached to the end of a 36' wide house with 4x4 knee braces at the 8' tall posts in an area with high seismicity.
The plan reviewer here requested a seismic load calculation for the 36' long line and I'm curious what R factor is appropriate...
