Engineering Report

Page 1 of 13
March 23, 2011 Revised on 12/13/2011 to Include Tensile Strength Tests
Mr. Stewart Wentworth Project Number 111114C
QUICK MOUNT PV
936 Detroit Avenue, Suite D
Concord, CA 94518-2539
Subject: New Construction Composition Mount (QMNC 3-3/4" Finished Height) Load Testing
Dear Mr. Wentworth:
As requested, Applied Materials & Engineering, Inc. (AME) has completed load-testing the New
Construction Composition Mount (QMNC) hardware. The purpose of our testing was to evaluate the
shear and tensile load capacity of the New Construction Composition Mount hardware attached to a
commercially available 2"x4" Douglas Fir rafter.
SAMPLE DESCRIPTION
Nine (9) mockup samples were delivered to our laboratory on March 9, 2011. Mockup configuration
consisted of three 16" long rafters at 7"o.c., screwed to 1/2" Structural 1 plywood. The 3-3/4" (finished
height) Quick Mount Standoff (QMSO) hardware is attached through the plywood into the rafter with
two 5/16"x3" lag bolts torqued to 15ft-lbs. Product hardware details are provided in Appendix B.
TEST PROCEDURES & RESULTS
1. Shear Strength Parallel to Rafter
Three samples were tested for shear strength on March 18, 2011 using a United Universal testing
machine. Samples were rigidly attached to the testing machine and a shear load was applied to the
5/16"x1" machine bolt connected to the aluminum standoff. The samples were loaded parallel to rafter at
a constant rate of axial deformation of 0.01 in./min. without shock until failure occurred. Based on the
above testing, the average ultimate shear load, parallel to rafter, of the QMNC hardware in Douglas Fir
was determined to be 1972 lbf.
The specific gravity and moisture content of the rafter was tested in accordance with ASTM D2395,
Method A (oven-dry). The average specific gravity and moisture content was determined to be 0.417
and 17.4%, respectively. Detailed results are provided in Table I. Test setup and mode of failure are
provided in Appendix A.

Summary of content (14 pages)