The readings below are related to Jonathan Smegal’s May 2017 LAB Event on vented and unvented roof assemblies. They address a range of building science principles and performance issues in different climate zones. Together, these resources provide a general introduction to this topic and related research.
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Top 5 Things to Read:
#1: Re-thinking Ventilated Attics: How to Stop Mold Growth in Coastal Climates
Marcus Dell (RDH), available from rdh.com
Discusses mold growth on the underside of sheathing in the Pacific Northwest, outlining causes and possible solutions. See also the related RDH study “Why Wood Frame Attics Get Wet and Moldy in the Pacific Northwest.”
#2: BSD-149: Unvented Roof Assemblies for All Climates
Chris Schumacher (RDH), available from buildingscience.com
This buildingscience.com article provides an overview of how unvented closed-cell SPF designs work.
#3: Canadian Spray Foam Guide
Jonathan Smegal, John Straube, and Aaron Grin (RDH), available from www.cufca.ca
Recommended enclosure details using light-density (0.5 pcf) and medium-density (2.0 pcf) polyurethane spray foam.
#4: How to Build an Insulated Cathedral Ceiling
Martin Hollday (GreenBuildingAdvisor), available from www.greenbuildingadvisor.com
Answers some commonly asked questions on cathedral ceilings from GBA’s readers.
#5: Issues Related to Venting of Attics and Cathedral Ceilings
Anton TenWolde (Forest Products Laboratory) and William B Rose (Building Research Council, University of Illinois), available at https://www.fpl.fs.fed.us/documnts/pdf1999/tenwo99a.pdf
This 1999 article is outdated as far as codes, but useful for its building science.
Literature Review of the Impact and Need for Attic Ventilation in Florida Homes
Danny Parker (Florida Solar Energy Centre), available from www.fsec.ucf.edu
Although focused on a particular geographic area, includes many points that are broadly interesting and applicable even in mixed climates.
How to Build Airtight Insulated Cathedral Ceilings
HGTV, available from www.hgtv.com
A quick read aimed at homeowners.