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06 IECC to 09 IECC Climate Zone 5B

J

joetheinspector

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06 IECC to 09 IECC

Table 402.1.1 under the Wood frame wall r-value column (climate zone 5b) the 06 code required R-19. The 09 code requires R-20.

As far as I know they do not make an R-20 batt insulation. There is an R-19 batt insulation available and for 25% more cost you can get an R-23 batt.

I know there are other types of insulation you can use to get an R-20. However the cost seems a bit steep to gain an R-1 value

Question: Does anyone know what the justification was at the code hearings to change the wall insulation from an R-19 to an R-20?
 
Joe, see footnote a. of the Table. The Energy Nazis had their panties all in a wad over this. There is no reason that the fiberglass batt manufactures can't produce a 5-1/2"

batt to give R-19. Blown Cellulose producers claim 3.7/in. or R-20.35 @ 5-1/2". OCSPF is listed @ R-19.25 for 5-1/2".
 
To follow up on ROPERPA’s comments. The original proposal was to require R-21 (high density fiberglass batts) BUT “some” (read Icenene) manufacturer could not achieve R-21 in 5 ½” but could meet R-20, SOOOOOO, guess who won out? One of my biggest peaves with ICC is the politics and buy offs. Another example was the IRC requirement for 2x2 plate washers at the end of braced wall panels, low and behold, Simpson was the only manufacturer. After other manufacturers started making 2x2 plate washers ICC changed the requirement to a 3x3 washer….again guess who made that…….you think Simpson. Besides the Codes becoming “reactionary” and “nanny” it is also falling to special interests.
 
joetheinspector said:
06 IECC to 09 IECC Table 402.1.1 under the Wood frame wall r-value column (climate zone 5b) the 06 code required R-19. The 09 code requires R-20.

As far as I know they do not make an R-20 batt insulation. There is an R-19 batt insulation available and for 25% more cost you can get an R-23 batt.

I know there are other types of insulation you can use to get an R-20. However the cost seems a bit steep to gain an R-1 value

Question: Does anyone know what the justification was at the code hearings to change the wall insulation from an R-19 to an R-20?
Click to expand...
And we can only calculate the R-value of the insulation components, not the other assembly or air barrier components?
 
My understanding was that R-19 fiberglass batt insulation was originally intended for 2x8 floor insulation. When stuffed into a 2x6 wall it only provided R-16.7. They had wanted to go to R-21, however only closed cell spray foam or high density fiberglass could provide that. So to get rid of the R-19 batts they decided on the R-20. When I went to a workshop on the 2009 IECC I came away with the "sense" they are trying to get the world to change to spray foam insulation. Look at all the items you can either eliminate, or less the impact of by using foam. Massachusetts is going to the 2012 IECC this summer. Ahhhh the enjoyment of learning new regulations.
 
Daddy-O

if you are located in a hurricane wind area you have to use a 3"x3"x1/4" steel bearing plate to anchor your sill plates to the anchor bolt. When I'm located in Massachusetts we are within a 110 mph basic wind speed zone. Most everything falls outside of the 2009 IRC (especially wall bracing) and into the Wood Frame Construction Manual.
 
OHHHH...OK. We have 2X2 washer requirement for garage stem walls just never seen a 3X3. FWIW..I would not buy them from Simpson. I would have them fabricated 100 at a time. Easy $$ for the local steel guy. Thanks for the info Gary
 
If you are in a seismic zone D like we are a 3x3x1/4 washer is required. When that requirement first came out some of the contractors were making them themselves because the supplies in this area didn't stock them. Now the suppliers stock them. I will have to check to see if the suppliers are getting them from simpson.

GBrackins you are right they do make good paper weights I have one in my office as well
 
We have a similar thing here in Canada. FG Batt listed as R20, but is only a R20 in steel stud walls. It's a R19 in 2x6 walls because of the compression. (Steel studs are 152mm where wood studs are 140mm).
 
I believe there was some kind of note in the 06 IECC about allowing the use of R19 batts in 6" nominal (5 1/2") cavities but it is probably the mandate to make energy conservation requirements more stringent in each successive code cycle that drove the change.

As to the washers, I gave away my '03 IBC so I can't be sure but I thought the IBC always mandated 3x3 washers for shear walls in light frame construction in SDC D. (BTW, the IRC seismic provisions are a joke. I would be very surprised if any engineer used the IRC.) Seismic design as regulated by the UBC had gotten a little out of hand. The design forces increased in '94 and again in '97. The IBC ratcheted the design forces back to about where they were in the '88 code but threw in prescriptive requirements such as the washers in light frame construction. The reasoning is that anchor bolt holes are usually overdrilled. Carpenters have to mark the plate, then drill the holes so they give themselves some generous fudge room. Simpson had come up with a plate with (4) screw holes in addition to the anchor bolt hole so be thankfull we aren't required to use that. The plate washer can only work through friction by making use of clamping force with the nut.

Since I'm here, the thing about prescriptive requirements for buildings is that if you try to make them comprehensive enough to cover all design conditions you get a mess such as what the IRC structural provisions have become. We have plenty of documentation to show that modest sized, wood frame construction, with regular floor plans, is as good as you can get for resisting seismic forces. The key is the regular floor plan part. Large, sprawling, custom homes with tall plate heights, acres of glass and very complex building lay-outs are one of the worst types of construction in an earthquake. The UBC recognized that and exempted all single family, light frame construction from seismic design requirements provided the building had no irregularities. Look at the '12 IRC. There is a little picture of a plan with both a plan and a vertical irregularity. By trying to make that code a do-all document we keep moving in the wrong direction.

dkengineer.com
 
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