143 - Venting Cathedral Roofs & 6-Sided Insulation Explained

A deep dive into cathedral roof design and insulation strategy. The team compares solid-sawn rafters vs. scissor trusses, smart vapor retarders vs. poly, and discusses optimal roof pitches. You’ll learn when to vent from the topside, from below, or go unvented entirely—and why those choices matter.
In the last 10 minutes, the crew unpacks one of building science’s trickiest topics: 6-sided containment of air-permeable insulation—and how it impacts attic R-values and energy performance.

PETE'S RESOURCES:

1. GBA "Five Cathedral Ceilings That Work:"

2. BSD-149: Unvented Roof Assemblies for All Climates

3. "Convection in Loose-Fill Attic Insulation - Measurements and Numerical Simulations"