Date of Award


Degree Name

Doctor of Philosophy


Industrial and Manufacturing Engineering

First Advisor

Dr. Tycho K. Fredericks

Second Advisor

Dr. Steven E. Butt

Third Advisor

Dr. Colleen Phillips

Fourth Advisor

Dr. Osama Abudayyeh


The objective of this study was to investigate the effect of roof slope on psychophysical roof shingling frequency. Twelve healthy males (21-30 years old) were used as participants. Experiment one was designed to determine Maximum Acceptable Roof Shingling Frequency (MARSF) for a workday period using psychophysical methodology. Results indicate that 198 shingles/hr is an acceptable roof shingling frequency for a workday. Furthermore, 2 hours is an acceptable testing period (equivalent to the workday). Postural sway and physiological variables support these findings. Experiment two was designed to study the effect of slope (18°, 26°, and 34°) on MARSF. Experiment two indicates that slope had a significant effect on MARSF, postural sway, trunk motion, and subjective variables. MARSF decreased with an increase of slope by 5.3% from 18° to 26°, while the shingling frequency decreased an additional 13.9% from 26° to 34°. Regression models were created to aid in predicting MARSF. These results will prove to be useful for practical applications for the reduction of the risk of occupational injuries and fatalities, while improving productivity and safety in the roofing industry.

Access Setting

Dissertation-Open Access