Choosing Roof Designs for New Buildings

A roof’s purpose Before you choose a roof design for a new building, you should understand the purpose of a roof. The primary purpose of roof is to shed rainwater and snow. A secondary purpose — and a less appreciated one — is to provide shade. A roof’s enemies...

Adult-Learning Experiments – 10 Findings

A Collection of Adult-Learning Research Results The book, Building Expertise by Ruth Colvin-Clark, offers one of the best summaries of adult-learning (pedagogy) research available. Like so many fields adult-learning pedagogy is hindered by dubious assumptions and...

Rainscreens and drainage planes

Building assemblies can get wet Building scientists assume that some rainwater leaks through the cladding or roofing and that water vapor migrates through insulated building assemblies, sometimes condensing within those cavities. These two phenomena both can dampen...

Possibilities for Wetting of Cellulose Insulation Part 2

Relative Humidity, Temperature, and Moisture Content This is Part 2 of a two-part series on cellulose insulation and moisture. Cellulose insulation is a hydrophilic material, meaning that absorbs moisture readily. Under certain conditions condensation dampens...

Air and Water Barriers

Old and new water barriers Once upon a time, builders stapled 15-pound asphalt felt to wall and roof structural sheathing as a water-resistive barrier (WRB). The 2012 International Residential Code (IRC) still specifies: “one layer of No. 15 felt… or other approved...