Algorithms have been proposed that can be used by the roofing designer to assess the moisture tolerance of a roofing system. Given the location and indoor conditions of the building, the designer can use these algorithms to determine if a vapor retarder is needed, if small leaks in the roofing system will translate into leaks into the building, and the relative ability for the roofing system to be self-drying. He can vary roof membrane color, insulation type and thickness, and deck permeance until he optimizes these parameters (subject to other limitations) from a moisture perspective. Experimenting with these algorithms will hopefully offer insight into the basics of moisture control.
The algorithms proposed in this paper are presently limited to roof systems and environmental conditions detailed in Table 1. Future work will include the analysis of roofing systems with a wider range of properties in order to establish the limitations of the predictive algorithms. A wider variety of insulation types, decks, and indoor vapor pressures need to be evaluated to assess the accuracy of the proposed algorithms to roofing systems and components that are presently not in our database.
Next Section - References
André O. Desjarlais