As he plans a new home in western Alabama, Weldon Koehn is considering an unusual wall assembly. In an era when high-performance, superinsulated walls are becoming ever-more common, Koehn is thinking about plain old brick.
“I have been very interested in using a 12-in.-thick, triple-wythe brick wall for all structural walls in our ‘forever’ home,” he writes in this recent Q&A post. “The wall would be structural, uninsulated, and the finish surface inside and out.”
Koehn says he was inspired by an article in Fine Homebuilding magazine that led him to videos by the builder, Clay Chapman.
“The wall seems to perform much better in the summer than most models would indicate,” Koehn writes. “However, the data is incomplete, and I have reservations [around] how this type of wall would perform through our very damp, cloudy winters. The simplicity of using only one material in the wall, combined with its strength, durability, resilience, and beauty have compelled me to try to study it out.
“Any thoughts?” he adds. “Am I crazy for even considering it?”
That’s where this Q&A Spotlight begins.
Interesting, but not cheap
There are just two things that really count, says GBA reader Akos: specific heat (the amount of heat the assembly can store) and its R-value per inch.
“When it comes to certain building techniques, there are a lot of hand-wavy arguments as to why it will work better than standard construction,” Akos says.
With the wall that Koehn is mulling, the R-value would be roughly 5 (which could be stretched to R-6, if the interior finish were installed over strapping). This has a specific heat capacity similar to concrete, although it is slightly less dense. Let’s say it’s the same as a 9-in.-thick concrete wall.