A large body of research and guidelines related to ice damming exists, and much of this material is available online. Following is a small selection:

Guidelines for Ventilating Attics and Cathedral Ceilings to Avoid Icings at Their Eaves
www.crrel.usace.army.mil/library/booksnongovernment/MP02-5778.pdf

Venting of Attics & Cathedral Ceilings
www.fpl.fs.fed.us/documnts/pdf2002/rose02a.pdf

Building Science Digest 135—Ice Dams
www.buildingscience.com/documents/digests/bsd-135-ice-dams/?searchterm=Building Science Digest 135

Building Science Insight 046—Dam Ice Dam
www.buildingscience.com/documents/insights/bsi-046-dam-ice-dam/?searchterm=Building Science Insight 046

Attic Air Sealing Guide and Details
www.buildingscience.com/documents/guides-and-manuals/gm-attic-air-sealing-guide/view?searchterm=Guide to Attic Air Sealing

A Do-It-Yourself Guide to Sealing and Insulating With ENERGY STAR®—Sealing Air Leaks and Adding Attic Insulation
www.energystar.gov/index.cfm?c=diy.diy_index

Retrofit Techniques and Technologies: Air Sealing
apps1.eere.energy.gov/buildings/publications/pdfs/building_america/ba_airsealing_report.pdf

This Web exclusive information is a supplement to Ice dam busting.