R-17 Composite Wall – Playing to Insulation Strengths
Originally published by: Fine Homebuilding — July 23, 2019
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There is more than one way to build an energy efficient wall assembly using spray foam as a key component. Even though spray foam is a fairly new product in the construction scene, it is clear that changes to the energy code combined with a sustained desire for continuous insulation and air tight wall construction will allow spray foam to quickly become a common application. There are a variety of ways to install and integrate spray foam into a building assembly. For additional insight, please review the approach taken by energy-efficient building expert architect Peter Pfeiffer from Texas.
No other insulation system I am familiar with provides the real r-value that spray foam does, accomplishes the air-sealing it does, or thwarts vapor flow as well. Closed-cell spray foam greatly reduces the chance for condensation within the framing of a home. I think it is critical that houses be built to thwart vapor flow correctly. I insulate all homes pretty much the same. However, in colder climates, I use 2x6 exterior walls, create a cold roof, and insulate the basement or crawlspace.
For additional information and commentary on the effects of insulation, please read the following articles:
- Thermal Insulation Topical Library
- Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
- Wood Framed Wall Insulation Calculator Explained
- Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
- Fear Building Envelopes No More with This Website & Videos
- Polyiso CI Helps Designers Achieve a 'Perfect Wall'
- An R29 Wall Is More Energy Efficient When Built As R20+5ci Why?