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foam insulation, no venting

I will try to get an answer on the 09 and 12. I am earnestly searching for the correct application of these products. It's not just the spray foam I see being applied this way. Some companies are dense packing cellulose so densely they are claiming it is air impermiable by definition. Thus far the code I enforce (06) doesn't appear to permit it whether it is air impermiable or not. All the proponants of not requiring the air-space give the reasons it doesn't need to be there. I wonder if there are any reasons it shouldn't be there.
 
I have to correct myself on the 2009 IRC. I thought it stated the same as the 2012 IRC, but it doesn't--it is the same as the 2006 IRC.
 
All the proponants of not requiring the air-space give the reasons it doesn't need to be there. I wonder if there are any reasons it shouldn't be there.
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On the current job concern about wildfire was a big driver but windblown snow and rain are mentioned in one of Lstiburek's articles. In most cut up and cathedral ceilings there is effectively no ventilation to begin with, the space is too small and often blocked. I've gone over the rafters with 2x2's to make space and left gaps around valleys and skylights but how often does it get done in a bidding situation. My own and one other house I've built have singing soffit vents in the right wind, annoying as heck. Wind washing reduces the sffectiveness of many installations as well. If this works, and I believe it does, it is a much easier way to get the job done right.

Thanks for the correction Ron, I'll keep quiet till next cycle. Sifu, I would appreciate knowing their interp and thought change in the '12 version. I'm not always committed to following the current code but rather in doing things correctly and realize it does lag behind changes in thinking and technology, lead paint and asbestos were state of the art at one time.
 
Yeah, DRP, I live out in the middle of nowhere and on a knob of a hill to boot.. I am fully aware of singing vents, and hate them.
 
My reading of the 06, 09 and 12 lead me to the following conclusions. 06 and 09 are basically the same, (09 seems to bridge a little between 06 and 12 with a little new info but doesn't go as far as 12 with "enclosed rafter assemblies"). 12 goes all the way by including the provision for enclosed rafter assemblies, reversing the 06 code and the interpretation I received. I will put this to ICC to confirm.
 
Email reply sent to ICC, don't know if they will respond to this or if I will need to do another formal request. We'll see.

Thank you for your reply. If I incorrectly referenced the IBC I

apologize. As a follow up, the codes concerning this issue seem to

have changed in the subsequent editions of the IRC and I would like to

confirm my understanding.

2009 IRC 806.4 still refers to unvented attic assemblies, much the

same as the 2006 IRC and though the code does include new language for

the use of air-impermeable insulation in attic assemblies it does not

include the language found in the 2012 for unvented rafter assemblies.

2012 IRC 806.5 now includes and defines the "unvented rafter assembly"

and prescribes for the removal of the air gap under certain

conditions, with the proper type and installation of insulation.

My conclusion is that from the 2006 IRC where no exceptions permit the

removal of the 1" air space in a vaulted rafter assembly, we have

moved to the 2012 IRC where, under some exceptions, it is permissable

to be removed.

Can you confirm my conclusions so that I may properly administer this

code section?

Thank You,

 
8065.jpg


Francis
 
Interesting...especially the part at the end of the first sentence just before the highlight.
 
I'm with RLGA, if that was always the intent, then.................the interpretation received from ICC the first go round means what?

Anyway, ICC responded, copied below. He is a man of few words.

September 26, 2012

Subject: 06 IRC R806.3, 09 IRC 806.4 and 12 IRC 806.5Q: Can you confirm my conclusions that from the 2006 IRC where no exceptions permit the removal of the 1" air space in a vaulted rafter assembly, we have moved to the 2012 IRC where, under some exceptions, it is permissible to be removed, so that, I may properly administer this code section?

A: Yes

There I have it! For now......
 
The authors of the Significant Changes document are confused or misinformed. "Cathedral ceilings" were not intended to be included in R806.4. On June 10th, 2004, I contacted a senior research scientist at PNNL, a sub-contractor to DOE, who worked on the development of this code section along with BSC.

Dear DOE Consultant: The approved DOE proposal EC48 03/04, included the addition of a new section to the IRC. R806.4 Conditioned attic assemblies: Unvented conditioned attic assemblies (spaces between the ceiling joists of the top story and the roof rafters) are permitted under the following conditions:

Section R806.1 of the IRC states "Ventilation required. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow. Ventilating openings shall be provided with corrosion-resistant wire mesh, with 1/8 inch (3.2 mm) minimum to 1/4 inch (6.4 mm) maximum openings."

This new section does not address the roof assembly of "enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters" otherwise known as a "cathedral ceiling" (not a code defined term).

The question is; was the new section, R806.4, intended to address this condition as well as a conditioned attic? Or, is it the intent of the DOE's proposal to continue to require" cathedral ceilings" to be ventilated regardless of the construction/insulation techniques used?
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His response -

Good question. You made me think about that one. We had not thought of using the new code section that way. No, Section 806.4 is not intended to apply to cathedral ceilings.(emphasis added)

DOE Consultant
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Roger:

Does the DOE dictate the ICC requirements? Recently trying to resolve differences between my structural engineer and the county plan checker the engineer told me: "I don't know why, I've designed everything to FEMA standards", he then pulled a FEMA manual off his bookshelf and showed me the details he followed. What is the relationship between DOE, FEMA, other government agencies, and the ICC?
 
Dick,

From the ICC Bylaws:

1.2 The Council is a nonprofit public benefit corporation and is not organized for the private gain of any person. The Corporation is organized exclusively as an organization described in Section 501©(6) of the Internal Revenue Code of 1986, as amended, or the corresponding provision in any future United States internal revenue law (the "Code"). Notwithstanding any other provision herein, the Corporation shall not engage in a regular business activity of a kind ordinarily carried on for profit and shall not carry on any other activity not permitted to be carried on by a corporation exempt from federal income tax under Section 501©(6) of the Code. It is organized under the Nonprofit Public Benefit Corporation Law for public and charitable purposes. Such purposes specifically include:With respect to buildings and structures: (a) the lessening of burdens of government through the development, maintenance and publication of model statutes and standards for the use by federal, state and local governments in connection with the administration of building laws and regulations, and (b) the lessening of the burdens of government through the performance of certain services for the benefit of federal, state and local governments in connection with the

administration of building law and regulation.

1.3 Principal Office - The Corporation shall have and continuously maintain a registered office in the State of California and a registered agent whose principal business office is identical with such registered office.
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DOJ, FEMA and DOE submit code change proposals to the ICC. Those proposals go through the process just like any other code change proposal. Not all of their proposals are accepted. Currently (2012), the IBC references two FEMA standards and one DOJ standard. DOE language is adopted into the body of the code(s).

Standard Referenced reference in codenumber Title section number

FIA-TB-11—01 Crawlspace Construction for Buildings Located in Special Flood Hazard Areas . . . . . . . . . . . . . . . . .1805.1.2.1

P646—08 Guidelines for Design for Structures for Vertical Evacuation from Tsunamis . . . . . . . . . . . . . . . . . . . . . . M101.4

DOJ 36 CFR Part 1192 American with Disabilities Act (ADA) Accessibility Guidelines for Transportation Vehicles

(ADAAG) Department of Justice, 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E109.2.4

What's scary is the congress of the United States passing legislation mandating that a particular ICC code (IECC) be adopted by the individual states as in the American Recovery and Reinvestment Act of 2009.
 
Thanks Roger, you are aware of the fact that our two fine Senators have introduced legislation that (if it becomes law) would appear to put FEMA in charge of everything nationwide. If and when we get a nationwide code will the ICC still be writing it? Or will we still have state inspectors with a bureaucracy of Federal inspectors following them up? Maybe end up like California's Medical Marijuana law, the state legalizes it and the Feds come in and arrest people? I can remember working a home in the 50s with an FHA loan, the local inspectors wanted the steel placed one way, the FHA inspectors came back and made us move it, the local inspector came back and made us move it back.

Maybe the racist Southern Democrats were right when they were screaming states' rights back in the 40s and 50s.
 
ICC is the only viable (?) code writing group since the legacy code groups have merged. NFPA is the only other (remote) possibility that I'm aware of. How many jurisdictions adopted NFPA 5000? I think you can count them on 1 hand.
 
If your jurisdiction is still enforcing the 2006 edition and where there may be a conditioned attic without ventilation below the roof deck, then the space is to become a habitable attic; would you prohibit a ceiling at the bottom of the rafters because the section of the code is explicit? The code is written to minimum standards; I have interpreted unvented assemblies superior to and exceeds minimum.

As for DOE interpretations and other government agencies has no authority without adoption into law as with building codes. Promoting the idea that it's a national security issue is a step in the direction of getting complete control of ones property. Smart grid is a first step to cutting power!

A couple of years ago during a seminar with a DOE representative; he answered in agreement that it met the intent to provide a minimum of R-19 or R-21 in a vaulted or cathedral ceiling such a an A-frame up to the upper third then have the prescribed R-38 where the majority of heat lost will occur. Now if you wrote to DOE about this assembly I bet the consultant may get confused and his opinion is to follow the prescribed methology.

Francis
 
As I read this I'm reminded of Plato's allegory of the cave. Many of us are describing the shadows on the wall. We really need to focus on science rather than opinions, even when those opinions are coming from those in some position of authority. I do appreciate your following up with the ICC Sifu, I was curious whether he was facing the sun or the cave wall, he just removed all doubt.

I had an interesting situation develop a couple of weeks ago. Our homeowners had come up for a week and were camping out. I recieved a "desperate" email describing what could only be a leak as there was a small puddle at the base of an exterior subgrade wall. Obviously it was due to the gutter contractor not having installed gutters in what they considered to be a timely manner. There is a 14' covered porch outside of this wall, soil under the porch is sloped away, foundation drains and gravel are in. I was baffled, for a bit. As I quizzed a sub that was there when the discovery was made my little bulb lit up. We are far enough along that a washer and dryer are in the basement, they hooked them up temporarily, there was no dryer exhaust, it was dumping into the basement. I set them down on their tail hard. I'm not at all certain they believe it was condensation or if I am just an uncaring workman. They are scientists and not dumb.

What I'm saying here is that we need to set our sights on finding real reasons behind doing things.
 
Like the ICC guy said, the amount of moisture "off-gassed" by a family is pretty amazing. Add a high moisture-output appliance and bingo. I am not a scientist or engineer and I really haven't been doing code enforcement for very long (relative to a lot of the forum) but I can read, and more importantly I can read between the lines. Moisture needs to go somewhere, moisture condenses on cooler surfaces, when that happens moisture becomes puddles. Not a real stretch.

I am continually amazed at how hard it is to get folks to accept things like that when they don't terminate a bath vent.

I generally think the original intent of the 1" air-space requirement did not consider the advent of spray foam/air impermeable products. When the product came out it happened for the consumer literally over-night. It seems the industry was able to figure out how that product might impact the code but the code was typically slow to either accept it or publish it. Maybe correctly so, do we really know the long term effect over a representative sample of projects yet? The science may work on paper but what happens in the field often deviates enough from the paper to render the end result a little skewed. I think of sealed and conditioned crawlspaces. In theory the system is great. The problem I see is in the field. I see very, very few "sealed" crawls. And of course I only see them on the final inspection. What the homeowner does in there or puts in there I'll never know. Even if done perfectly it can be rendered useless by an unknowing or uncaring owner and go from becoming an asset to the building to a hazard. I am a little nervous about some of the more interdependant systems. It seems I am seeing more and more of them that will rely on the owners to maintain.
 
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