Research Report 138: Plywood Diaphragms

Commonly accepted plywood diaphragm construction is applicable for design shears significantly higher than those previously published. Multiple rows of fasteners in wide framing members are used to develop the higher shear loads sometimes required for buildings in higher seismic areas.

This publication is designed for: engineers, architects

This research report details the design and testing of eleven diaphragms, up to the limiting stress of the plywood. The effects of openings in the diaphragm and field gluing of plywood sheathing are also investigated.

Key sections include:

• Recommended shears for high-load wood structural panel diaphragms

• Test setup

• Test procedure

• Materials and specimens

• Control diaphragm – panelized construction

• High-load diaphragm – two-layer panelized construction

• High-load diaphragm – conventional construction

• Diaphragms with openings

• Field-glued diaphragms

• Diaphragm with framing spaced 5 feet o.c.

Published by APA — The Engineered Wood Association.