Wet spray cellulose
rdjenning
| Posted in Energy Efficiency and Durability on
Im fast approaching the building of a new house. my builder and insulator are trying to persuade me to go with 2×4 walls stating that with the damp spray cellulose it would take me 40 years to recover the cost of using 2×6 walls ?
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Replies
R.D. Jenning,
First of all, we need to know your climate zone or geographical location.
Second, we need to know what your question is. I'm not sure.
Maybe your question is, "Should my walls have 2x4 studs or 2x6 studs?"
Maybe your question is, "Should I insulate my walls with damp-spray cellulose or a different kind of insulation?"
I'm using the wet spray cellulose. My question was should I go with 2x4 or 2x6 walls. The builder said it would take 40 years to recover the cost of using 2x6 walls . I want to know if that's accurate. He also added that I would be better off adding ceiling insulation rather than going to 2x6 walls. I live on the missouri southern boarder
Thanks again
Ron
Ron,
You are located in Climate Zone 4. According the the 2012 IECC, a building code that has been adopted in most states but which may not be enforced in rural areas, the minimum R-value requirement for walls in your zone is R-20.
The nominal R-value of a 2x4 wall insulated with cellulose is only R-13, so that doesn't meet minimum code requirements. The 2x6 wall would have a nominal R-value of R-20 -- barely meeting code requirements. So you need the 2x6 wall.
If you want to work out how much energy/money would be saved with the difference in insulation, check out this article: https://www.energyvanguard.com/blog/going-beyond-2x4-walls-warm-climate
Hope that helps!
To find out what code applies to your neck of the woods, use the Code Resource Center: https://www.energycodes.gov/adoption/states/missouri. Click on the residential tab.
Or from the Building Codes Assistance Project (BCAP) - https://codewatcher.us/states-codes/missouri-building-codes-and-contacts/. Note the one-line description of current residential code: "Missouri has no mandatory or voluntary statewide energy code for private residential construction."
But if you are on the GBA website, you are most likely looking for information on homes that are worth more, worth more investment. You are building a structure that may well outlive you; just building to code is missing an opportunity to up your home's game for the long haul.
Peter