T-studs vs external insulation
canada_deck
| Posted in General Questions on
The best practice in many areas right now seems to be 2*6 walls with external insulation. I imagine it’s better bang for the buck than double stud walls and 2*8 walls become too expensive for lumber. However, external insulation seems like a pain for detailing, especially in regions where you also need to do a rainscreen with a 3/4″ gap.
It’s got me thinking: If they made 8″ or 10″ t-studs, would that be a preferred wall assembly with no external insulation?
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I'll be thrilled on the day t-studs and the like are routinely stocked in the big box stores and lumber yards. I'd really like to use them in my work but must stick with stuff which is readily available. I agree about the complications of external insulation. My concern is that so many contractors just aren't familiar with the work and it means that much more chance for mistakes or poor quality work, as well as price padding.
I appreciate the skill and dedication of the builders we see in videos like Matt Risinger puts together. But those folks are NOT the norm.
> and 2*8 walls become too expensive for lumber.
Have you really priced this?
I see stud length (i.e. 8') 2x8s very close in price to 2x6s.
Interesting. It does all add up though and there are some other downsides such as the extra weight of the walls (just makes it harder to build,) and there still is a lot of thermal bridging. I've got to assume those are why people go to 2*6 with exterior insulation instead of 2*8 walls. My thinking is if the weight and thermal bridging problems were solved with something like t-studs, it may be a preferrable solution to external insulation.
canada_deck
"there still is a lot of thermal bridging. I've got to assume those are why people go to 2*6 with exterior insulation instead of 2*8 walls."
I think the main advantage is keeping the walls - especially the sheathing - warmer and dryer.
re. the extra weight of the walls.
I was curious about that too and asked around about it here on GBA a year or so back. I'd really like to hear what a production framing carpenter has to say on the subject. What would be their concerns if they were asked to bid on a package that called out 2x8s?
If there are any production framers reading this I hope they'll chime in.
I just did a fun little exercise, calculating the volume of wood (as a proxy for weight) for a 8' x 24' simple wall section:
- 2x8 studs 24" OC: 19,836 in^3
- 2x6 studs 16" OC: 19,800 in^3
(I used different OC measurements because framers are very accustomed to 2x6 walls 16" OC.)
I built a sample Tstud 2x6 wall this summer, purchased them from the factory. Very easy to frame following the field guide.