New measurement methods recently developed at the National Institute of Standards and Technology were used to measure the sorption isotherm and permeability of several low-slope roofing materials at a mean temperature of 24 "C (75 "F). The materials included: fiberboard, perlite board, exterior-grade plywood, polyisocyanurate board insulation with glass-matt facers, and glass-fiber board insulation with a facer.

For the sorption isotherm measurements, the materials were placed in various ambient relative humidities ranging from a dry to a saturated state. The equilibrium moisture content plotted versus ambient relative humidity at 24 "C (75 ˇ®F) gave the sorption isotherm. Separate sorption isotherms were obtained for specimens initially dry (adsorption isotherm) and specimens initially saturated (resorption isotherm).

For the permeability measurements, a series of cup measurements was performed, and the permeability was plotted as a function of the mean relative humidity across the specimen. The measurements revealed that the moisture properties of building materials are often significantly dependent on average relative humidity. Standard measurement methods currently in use in the United States do not adequately account for the effect of relative humidity on moisture properties.

• HAM: material properties : low-slope roofing materials

1. A computer analysis of the moisture performance of roof constructins in the U.S. DOE Moisture Control Handbook
2. A mathematical analysis of moisture and heat transfer in the roof cavities of manufactured housing
3. A prarmeteric study of wall moisture contents using a revised variable indoor relative humidity version of the "MOIST" transient heat and moisture transfer model
4. An analysis of moisture accumulation in the roof cavities of manufactured housing
5. Computer analysis of wall constructions in the moisture control handbook
6. Empirical validation of a transient computer model for combined heat and moisture transfer
7. Experimental verification of a moisture and heat transfer model in the hygroscopic regime
8. Heat and moisture transfer in wood-based wall construction: measured versus predicted
9. Indoor ventilation requirements for manufactured housing
10. Manufactured housing walls that provide satisfactory moisture performance in all climates
11. MOIST: A PC program for predicting heat and moisture transfer in building envelopes, Release 3.0
12. Water vapor permeability measurements of common building materials
13. Water vapor sorption measurements of common building materials  

1. An educational hygrothermal model: WUFI-ORNL/IBP
2. Investigation of common thermal bridges in walls
3. Laboratory measurements of the drying rates of low-slope roofing systems
4. Moisture control in low-slope roofing: a new design requirement
5. Moisture studies of a self-drying roof: tests in the large-scale climate simulator and results from thermal and hygric models
6. Moisture: its effects on the thermal performance of a low-slope roof system
7. Self-drying roofs: What? No dripping!
8. The whole wall thermal performance calculator-on the net
9. Whole wall rating/label for structural insulated panel: steady-state thermal analysis