NRCA is proud to offer the EmpowerAll Scholarship—apply by Sept. 29!

Drying Capacity of Underpressure and Mechanical Ventilation Solutions in Low-Slope Roof Structures

To obtain a copy of a specific publication, users should contact the publication's publisher directly.

Abstract
MOISTURE MANAGEMENT IN low-slope roof structures is a challenge for long-term integrity. When present, moisture within roof structures can reduce the functional properties of the insulation layer, increase the risk of mold proliferation that can cause premature decay of the structures, and shorten the lifespan of the roof itself. Moisture accumulation within the roof structure can result from various factors, including condensation due to temperature differences or shifts and unintended water ingress from leaks. Moisture can also enter the roof assembly through air leakage paths in the vapor barrier or other layers. In such cases, warm, humid indoor air moves by convection into cooler parts of the insulation, where the water vapor condenses. This process can lead to localized wetting deep within the insulation, even in the absence of a bulk water leak.
Date
7/2026
Author(s)
Katarina Hellen
Page(s)
14-16
Keyword(s)
moisture; condensation; insulation; water


Note: Documents in this section are provided as Adobe Acrobat PDF files. In order to print and view PDF files, the Adobe Acrobat Reader software/plugin, which runs on Microsoft Windows, Macintosh, OS/2 and various versions of UNIX, must be installed on your computer. Adobe Acrobat Reader is available for download as freeware from Adobe Acrobat's website. Please note that the resolution of on-screen versions is not as high as printed versions of PDF files.

Advertisement

Subscribe for Updates Join 25,000+ roofing professionals following NRCA

Subscribe to NRCA