Monitoring of Unvented Roofs with Diffusion Vents and Interior Vapor Control in a Cold Climate

You are here

Lead Performer: Building Science Corp. – Westford, MA
-- Dupont – Wilmington, DE
-- Owens Corning – Toledo, OH
-- Cosella-Dörken – Beamsville, Ontario, Canada
-- K. Hovnanian Homes – Red Bank, NJ
DOE Total Funding:  $430,000
Cost Share:  $115,000
Project Term: August 1, 2016 – August 31, 2019
Funding Opportunity: 2016 Building America Industry Partnerships for High Performance Housing Innovation

Project Objective

Moisture is a common concern in unvented attics with fibrous insulation. This moisture typically accumulates at the roof ridge, and can lead to mold and structural damage. Building Science Corp. and partners will evaluate the use of a vapor control membrane, or diffusion vent, which could substantially reduce the risk of moisture issues in roof assemblies with fibrous insulation. This project will field-test this solution in a cold climate new construction test house over three years, and will also test the approach in a high-impact existing home weatherization application to be determined through stakeholder engagement..

Project Impact

This project’s moisture-managed fibrous insulation solution can achieve code and above-code performance (R-49) while reducing insulation material costs up to 80% and potentially reducing HVAC energy use by 10% or more by locating the HVAC and duct system in the conditioned attic.


DOE Technology Manager: Eric Werling
Principal Investigator: Dr. Joseph Lstiburek, Building Science Corporation

Related Publications

Field Testing of an Unvented Roof with Fibrous Insulation, Tiles, and Vapor Diffusion Venting (February 2016)

Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot- Humid Climates (September 2015)