You Need the Right Type of Plywood

You need the right type of Plywood

The two types of plywood available are Rated and Structural One, but for shear wall use the plywood must have 5 plies. Rated Plywood can be made of any species of wood while 10% stronger Structural 1 must be made of denser Southern Pine or Douglas Fir.  Overall it is not that big a deal if you use Rated instead of Structural one.

Avoid 3-PLY PLYWOOD

3 ply plywood tore in Northridge Earthquake

Plywood made with only 3 plies tore in the 1994 Northridge Earthquake and should not be used

Shear walls made of 3 ply plywood tore in the Northridge Earthquake so the City of Los Angeles downgraded  the acceptable limits for 3-ply plywood to a maximum of #200 plf.  On page 10 of the Wood-Frame Subcommittee Findings Report published immediately after the Northridge Earthquake it says: “The performance of 3-ply construction has raised questions of its ultimate capacity.  Horizontal tearing has occurred on some outer face plies above the inner ply seam.  Values for all 3-ply panel construction were therefore reduced to 200lbs/ft maximum.”

 

Areas Served

San Jose,Sunnyvale, Fremont,Oakland,Berkeley
And Surrounding Areas
408-664-6355
510-548-1111

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License Info

Works' Comp RWCC64393236
Contractors Lic #558462
Bond #SC6334450
Liability Ins PCA 1045011
Link to Contractor's License Board