2009 IRC Table 402.2.5 Steel-Framing Ceiling, wall and floor insulation (R-value)

[joetheinspector]

I am studying for the ICC IECC residential test and I have run into a couple of questions.

Table 402.2.5 Steel Frame Ceiling, wall and floor insulation (r value)

First row under Steel Joist Ceilings

1st column R-30 (I understand wood frame R value)

Question: second column

R-38 in 2x4 or 2x6 or 2x8

R-49 in any framing

I understand the first row (R-38 . . .)

What does “R-49 in any framing mean” ?????

 

[joetheinspector]

opps wrong code reference. it should have been 09 IECC