Can wet roof insulation be dried out
Nondestructive techniques are being widely used to locate wet insulation in compact roofing systems. Now that wet insulation can be found, breather vents and so called ''breathable'' membranes are being promoted to dry out wet insulation, thereby recovering its thermal effectiveness. Exposure tests in New Hampshire indicate that the above venting methods are all rather ineffective in drying sealed specimens of perlite and fibrous glass roof insulation. It would take many decades to dry specimens at the rates measured over the past two years. Cross-ventilation within the insulation increased the rate of drying. For perlite insulation, the faster rate would still result in a drying time measured in decades. For fibrous glass insulation, the drying time was reduced to 13 years. The authors have succeeded in drying fibrous glass insulation in a roof by removing the water with a vacuum cleaner. In a series of tests with a total duration of 134 h, about 0.42 m/sup 3/ (110 gal) of water was removed from a 17-m/sup 2/ (180-ft/sup 2/) area of 38-mm (1.5-in.)-thick insulation. Before the water was removed the insulation had only 21 percent of its dry insulating ability; afterward it had 83 percent.
- Research Organization:
- US Army Corps of Engineers, Cold Regions Research and Eng. Lab., Hanover, NH
- OSTI ID:
- 5343359
- Journal Information:
- Am. Soc. Test. Mater., Spec. Tech. Publ.; (United States), Vol. STP-789
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of moisture on thermal resistance of some insulations in a flat roof under field-type conditions
Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot-humid Climates