What is the R Value of a 2x6 dense packed cellulose wall?

I am reviewing the requirements of the new Maine Uniform Building and Energy Code that goes into effect 12/1/2010.  The required R value for a wood framed wall is R20. If I assume the Dense Packed Cellulose has an R value of 3.4 per inch and a 2x6 is really only 5.5" deep, then 5.5" of cellulose is only R18.7 which doesn't quite meet the standard.

I could put in R21 fiberglass and meet the standard, but I am sure the cellulose would out perform the glass in the real world.

How does everyone else view this subject?

Views: 4711

Reply to This

Replies to This Discussion

According to National Fiber's website a 2 x 6 wall at 5.5 " thick has an R value of R20 when dense packed at 3.5 lbs per cubic foot. The reason the Code has a minimum wall insulation requirement of R20 is because thats as good as it gets with celluloce, if the cellulose manufacturers hadn't been allowed their input the minimum would be R21 (fiberglass batts).
Thanks for the reply Scott. I found that on the National Fiber site after I posted the message.

What approach do you plan to take to get R49 in a cathedral ceiling where the slope area is greater than 500 ft2 or 20% of the total ceiling area?

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Malcolm McKelvie replied to Alan Gindt's discussion Minneapolis Blower Door System for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"yes I would pay the delivery fee!"
yesterday
Alan Gindt replied to Alan Gindt's discussion Minneapolis Blower Door System for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Malcolm, If you want to pay delivery from USA we can talk. Otherwise no thanks."
yesterday
Malcolm McKelvie replied to Alan Gindt's discussion Minneapolis Blower Door System for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"How old is it? I assume it is in good working order? I'm interested in it but the price needs…"
yesterday
William H Nickerson replied to Kim Tanner's discussion Fantastic innovation
"So that's where you use those True Flow plates....."
yesterday
Colin Genge updated an event
Thumbnail

Passive House Testing Webinar with Kevin Brennan of the Passive House Academy at Online

September 29, 2015 from 1pm to 2pm
Tests needed to qualify as a passive houseWhy we’re seeing an increase in PH buildingsBest…See More
yesterday
Colin Genge updated an event
Thumbnail

DM32 Smart Gauge 101 Webinar at Online

September 22, 2015 from 1pm to 2pm
Webinar Learning Objectives:Gauge settings and operationCalculate results in the gaugeUpdate the…See More
yesterday
Colin Genge updated an event
Thumbnail

Blower Door 101 Webinar at Online

September 15, 2015 from 1pm to 2pm
See how easy it is to do your first test. Learn tips to perform your first duct test in only twenty…See More
yesterday
Colin Genge updated an event
Thumbnail

Zone Pressure Diagnostics (ZPD) with Bill Eckman of NME$A Webinar at Online

September 10, 2015 from 1pm to 2pm
Benefits and limitations of Zonal Pressure Diagnostics (ZPD).Best practices for accurate…See More
yesterday

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service