Quiz 4 insulation r-value discrepency?

I was taking quiz 4 on R-values for insulation and one of the questions was:
According to the 2006 IRC, the minimum R-value for a ceiling in a home located in Zone 3 is:
Well, I studied that chart not 5 minutes before and I know it is R-38. But that answer was not one of the multiple choice answers given. I chose 30 and got it right, but the chart says 38. Am I looking at the wrong chart? And if this question is in the wrong place I apologize.

Keep taking course quizzes and you will find more discrepancies.


Welcome, Timothy, to our forum…where there are no stupid questions…Enjoy! :smile:

Many more…

I believe the quiz answer was correct with R-30 being the minimum for zone 3.
Be careful with the terms “minimum” vs “recommendation”. They are different.
The IRC minimum for zone 3 is in fact R-30 for ceilings.
The DOE recommendation for zone 3 is R-38 or more. DOE only recommends residential insulation. They do not enforce.

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Was the chart you are referring to in the course manual? If so then someone used the wrong chart as in 2006 it was R30 in Zone 3. It was changed to R-38 in the 2012 code cycle. I suspect the course was updated to reflect newer requirements except the answer was probably never changed.


Should we memorize the charts in the study materials, or just keep a book/cheat sheet of some sort with us ?

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If you are inspecting in the same zone you can easily remember the proper R-value for your area.
By the way, Judith welcome to the forum have fun and enjoy. :smile:

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Thank you Scott!
I am more curious about the test at the moment. I will be working in zone 7 once I get certified. I’m certain I can remember things specific to that zone! Thanks again!

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Your welcome and good luck. :smile: