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Re: (2)2x vs. 3x in wall anchorage

[Subject Prev][Subject Next][Thread Prev][Thread Next] UBC no longer carry table for "Holding Power of Bolts." I did some calculations on the seismic shear capacity for the old 2x and the new 3x mud sills following 91 NDS. 

I got:

748 pounds for 1/2" dia. anchor in an existing 2x RWD sill,
1077 pounds for drilling in a new 5/8" dia. anchor in an existing 2x RWD sill &
1488 pounds for 5/8" dia. anchor in a new 3x pressure treaded DF #1.

I would like to find out what values are you using?

Sam Chang, SE

At 06:03 PM 4/7/00 -0700, you wrote:
>The requirement of 3x applies to new construction. However, you can utilize an
>existing 2x for wall anchorage. The loads should be concentric on the (E)
>framing and adequate nailing to the plywood panel is necessary to develop the
>O/P wall loads into the subdiaphragm sheathing. The purpose of using 3x is to
>achieve proper nailing pattern at the plywood panels edges without splitting
>framing member and maintaining enough effective area of the framing member
>loss of section due to drilling. An alternative to drilling the (E) 2x is to
>self drilling screws.