• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

C.I. bypass

R

rbcameron1

Member
Joined
Mar 19, 2014
Messages
19
Location
Nebraska
Are there any instances where I can get away without having to use cont. insul. on my exterior walls? I have a mixed use building with commercial on the first floor and residential apartments (wd const.) w/ R19 batt in the walls. I'm in category 5 (Nebraska) as far as IECC 2009 is concerned. I can probably get away with it by passing COMcheck right?
 
You can also use the annual energy cost budget method in ASHRAE 90.1. Walmart uses this method to avoid CI
 
Not to steal the tread, who here accepts R19 on a Res or Com-Check if placed in a 2by6 wall cavity? Our office policy is the Res or Com-Check must be revised to indicate R18. This is based from manufactures testing showing the effective R Value of R19 when installed and compressed into a 2by6 cavity.
 
If the U-Factor Alterative, IECC 2009: 502.1.2, is used then Table 502.1.2 is applicable. This table never mentions CI insulation.
In speaking with an ICC instructor at a seminar, this could be a complaint method.
 
502.1.2 U-factor alternative. An assembly with a U-factor,
C-factor, or F-factor equal or less than that specified in
Table 502.1.2 shall be permitted as an alternative to the
R-value in Table 502.2(1). Commercial buildings or portions
of commercial buildings enclosing Group R* occupancies
shall use the U-factor, C-factor, or F-factor from the
“Group R” column of Table 502.1.2. Commercial buildings
or portions of commercial buildings enclosing occupancies
other than Group R shall use the U-factor**, C-factor or F-factor
from the “All other” column of Table 502.1.2.

Zone 5
*Residential portion = U-0.051 (19.61)

**Commercial portion = U-0.064 (R-15.62)
 
ICE said:
. What does the C stand for.

Thanks
Click to expand...

C-FACTOR (THERMAL CONDUCTANCE). The coefficient of heat transmission (surface to surface) through a building component or assembly, equal to the time rate of heat flow per unit area and the unit temperature difference between the warm side and cold side surfaces (Btu/h ft2 × °F) [W/(m2 × K)].
 
Oh that....Ya I use that all the time....R-38C has better performance numbers than plain old R-38.
 
You must log in or register to reply here.
Top