Humans aren’t good “talking” thermometers, because we “feel” thermal conductivity. Want proof? As my college physics prof often told us, you’d rather the outhouse had a wood seat than a porcelain one on a cold night (even though they’re the same temperature)!
Well, just like porcelain, steel is a much better thermal conductor than wood, and sometimes that’s a disadvantage. For example, if a 6” steel stud wall is filled with nominal R-21 cavity insulation, the effective R-value of the wall only increases by R-9.05. That’s more than a 50% reduction, merely due to the thermal conductivity of the studs! So rather than insulate the cavities of steel stud walls, it is much better to attach continuous insulation to the outside of high conductivity framing. An unbroken layer of insulation significantly reduces the problem of thermal bridging, which saves money both during construction and during the lifetime of the structure
Not only is the use of continuous insulation on steel stud walls a good idea, it is a requirement of the IBC and the IECC! To learn more about this application, check out resources available specifically for commercial buildings. Use the steel wall calculator to see how much continuous insulation can improve your thermal performance!
Please watch this short video, part of a series of videos we are highlighting, for a quick review of the concepts introduced above:
For additional information, review the following articles, as well as the previous videos in this series:
Perfect Wall Articles
- Creating the ‘Perfect Wall’: Simplifying Water Vapor Retarder Requirements to Control Moisture
- Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
- Wood Framed Wall Insulation Calculator Explained
- New Wall Design Calculator for Commercial Energy Code Compliance
- Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
- Continuous Insulation Solves Energy Code Math Problem
- Fear Building Envelopes No More with This Website & Videos
- Video: Thermodynamics Simplified Heat Flows from Warm to Cold
- Video: Moisture Flow Drives Water Induced Problems
- Video: How the 'Perfect Wall' Solves Environmental Diversity
- Video: How Important Is Your WRB?
- Video: A Reliably Perfect Wall Anywhere
- Video: The Best Wall We Know How to Make
- Video: How to Insulate with Steel Studs
- Video: Thermal Bridging and Steel Studs
- Video: Better Residential Energy Performance with Continuous Insulation
- Video: How to (Not) Ruin a Perfectly Good Wall
- Video: Tar Paper and Continuous Insulation? No Problem!
- Video: Do CI and WRBs Go Together?
- Video: Assess Your 'Perfect Wall' Using Control Layers