The base tGSt method has been proposed by Carballo, Holzer and Murray [5] as a means of determining the strength of standing seam roof systems under gravity loading. The objective of this thesis is to evaluate the accuracy of the base test method. To do this, eleven sets of tests were performed at Virginia Polytechnic Institute & State University (VPl&SU). Each test set consisted of a single span base test from which a failure load was predicted for the corresponding three span confirming test. Results of two test sets recorded in Reference [5] were also used to evaluate the method. A secondary objective of this thesis is to comment on the effects that system components (purlin orientation, clip type, bracing configuration, panel type, insulation and purlin type) have on the strength of the system. Results from proprietary tests conducted at VPI & SU were used in conjunction with the results from this research to accomplish the secondary objective. / Master of Science