Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot-humid Climates

Description

BSC TO5 Task 7.1 Field Testing Unvented Roofs with Asphalt Shingles in Cold Climates - Bolingbrook, IL 60440 BSC TO5 Task 7.1 Field Testing Unvented Roofs with Asphalt Shingles in Hot-Humid Climates - Friendswood, TX 77546 To understand the long-term moisture performance of unvented roof assemblies with fibrous insulation, the U.S. Department of Energy's Building America team Building Science Corporation built and monitored test roofs in two climates: a cold-climate test house in Bolingbrook, Illinois (Chicago area; zone 5A), and a hot-humid test house in Friendswood, Texas (Houston area, zone 2A). The Chicago-area test bed had seven parallel experimental rafter bays. The assemblies included a control vented compact (cathedral) roof, a dense-pack cellulose unvented roof, and an unvented roof with a "diffusion vent" (a strip of vapor-permeable gypsum sheathing at the ridge to allow drying). The interior finish was gypsum wallboard (GWB) with latex paint. The other four bays were top vent roof assemblies, which have a polypropylene breather mesh between the roof sheathing and the asphalt shingles to allow ventilation drying of the assembly from underneath the vapor-impermeable shingles. Two of the four "top vent" roofs were fiberglass batt and two were dense-pack cellulose roofs with either interior GWB or open to the interior. Wintertime moisture-related failure was accelerated by providing interior humidification (22.2 degree C [72 degree F]/50% relative humidity [RH]), which is known to be an extreme interior loading). Data were captured over 8 months, including a winter and the following spring and early summer.

Resources

Name Format Description Link
33 DOE Report http://www.eere.energy.gov/buildings/publications/pdfs/building_america/unvented-roofs-asphalt-shingles-cold-hothumid.pdf
53 Spreadsheet of monitored data https://data.openei.org/files/5512/0000_Unvented_Chicago_Data%5B1%5D.xlsm
53 Spreadsheet of monitored data https://data.openei.org/files/5512/Houston_Unvented_Data%5B1%5D.xlsx

Tags

  • hvac
  • roof-insulation
  • conditioned-attic
  • building-america
  • unvented-attic
  • multifamily
  • new-construction
  • buildingamerica
  • asphalt-shingles
  • ashrae-160
  • cost-effectiveness
  • residential
  • cellulose
  • moisture-monitoring
  • insulation
  • hot-humid
  • temperature
  • single-family
  • existing-home
  • cold
  • roof-retrofit

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