# foam insulation, no venting



## codeworks (Sep 20, 2012)

i see more and more roofs down here being insulated with blown foam, directly to the underside of roof sheathing and encapsulating rafters with zero roof venting. i see this as a potential problem down the road, as i've seen this same practice up north, and it has led to rafter failure and  sheathing failure and extensive, and expensive repair years down the road. the problem comes from what i would call dry rot. may not be "dry", actually. this appication leaves no way for the encapsulated strucure to breath. and any condensation that forms on the underside at night when it cools, gets trapped. any moisture in the wood componenets is trapped. over time, it will start to rot. i've torn a dozen roofs in vermont and had to reframe and resheath due to this very application. plywood temperature get too extreme, glue fail, which leads to delamination of the plyscore layers.  blown foam was "BIG THING" in the early 70's there. not so much any more. buildings need to breath. i've taken houses apart that were built in the 1800's that had  newsprint tacked up for "sheathing paper", prior to installation of clapboards or split shakes,  that was installed over skip sheathing and that wood was as solid as the day it was built. anybody have any input. please, not the thermal barrier quotes and all that bs from the code book, we look at all that, ask for all that.  rather i'm seeking insight or experince into how this will stand up over time. i don't see it as good. what i've posted is my experience.


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## fatboy (Sep 20, 2012)

Older houses breath better, no doubt. I also have torn into a few roof systems that were not vented in any fashion, vaulted ceilings for instance, where the sheathing had failed after only 15 years. Where, doing a real estate home inspection for an aquantence on a 100+ year old farm house, with no attic ventilation, it was solid as a rock. As far as the direct applied foam isulations, I guess time will tell, but I share your concerns.


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## BSSTG (Sep 20, 2012)

Greetings

Yea I just looked at one this week. I had never seen one until about a year ago. That house, which is quite large has had minimal elect bills so I'm told. I don't expect to work here in this town long enough to see long term effects. Should be interesting though. The builder that did that house says he has done a few with no problems. Sure seems like the roof deck would take a pounding in our Tx climate.

BS


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## codeworks (Sep 20, 2012)

if there were end walls to provide venting, mybe it wouldn't be so bad, but this is all on multi hip/valley roofs, with no end walls, no place to install and end louver. odd. future work for someone.


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## codeworks (Sep 20, 2012)

done a few with no problems. yea, in the recent past. it's the older ones that will show the issues. these houses 8, 10, 15 yrs from now, will have bad roof sheathing at a minimum. looking to move? we need an inspector ! no bs (pun intended) lol!


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## globe trekker (Sep 20, 2012)

codeworks,

Is your application an enclosed attic space,  or a conditioned attic assembly?

(RE: Section R806 in the 2006 IRC)?

.


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## codeworks (Sep 20, 2012)

it's a conditioned attic assembly. still, presents potential for failure down the road.


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## globe trekker (Sep 20, 2012)

> it's a conditioned attic assembly. still, presents potential for failure down the road.


Thanks for the reply! I am not a fan of the spray foamed attics, and notreally of spray foam in general. I too believe that houses ought to breathe,

..a little bit anyway!

.


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## Bama dav (Sep 20, 2012)

Dont forget the thermal barrier/ignition barrier that is required.316.4 (2012 IRC).


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## RLGA (Sep 20, 2012)

The purpose for the venting is to allow the sheathing to dry out from moisture, from water vapor in the air, that has condensed on the underside of the sheathing.

If the foam is closed-cell polyurethane, then the likelihood of moisture reaching the sheathing is almost nil, since closed-cell polyurethane is an excellent water and vapor retarder (low permeability).  Thus, the need to vent between the foam insulation and sheathing is no longer present.

If the foam is open-cell polyurethane, then it will have a slightly higher vapor permeability than closed-cell, but it is still controlled, so the possibility of moisture reaching and condensing on the sheathing is low if provided in the recommended thickness.  Thus, the need for ventilation is also not necessary.


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## Rider Rick (Sep 20, 2012)

Is the spay-on foam for R-value or for air infiltration?


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## RLGA (Sep 20, 2012)

Both. Polyurethane foam has a high R-value.  The closed-cell type has a greater R-value than the open-cell type.  The foam also creates an efficient air barrier.


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## TheCommish (Sep 20, 2012)

Foam technology has changed, I would venture the house done in the 70’s used formaldehyde foam that came and went quickly. I do not know the permeably of the formaldehyde foam or much about it.

The foams today are in my opinion much better.

The issue is moisture in the building and its condensation on cool surfaces, even if the house has fiberglass that can breathe excess moisture will condense on cold surfaces leading to rot. Sure the older buildings that breathed had no problems, just the dollars flying out the walls with the heat that was not keep in.

Building are a system and there is science involved it is unwise seal up a building to keep in the condition air and not deal with the moisture of everyday living and air quality through sensible controlled ventilation.


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## tmurray (Sep 21, 2012)

I'd feel much better about it if the contractor in question actually followed some kind of science rather than "I've built a couple like this and had no problems" approach.Unvented roof assemblies

Also, for those who think that a building needs to breathe; Air Leaks How They Waste Energy and Rot Houses


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## Sifu (Sep 21, 2012)

I asked ICC about this very issue and just got the response.  I have had questions about the validity of whether it is acceptable to eliminate the air space along the underside of the roof sheathing in a vaulted rafter space.  The ICC answer was that under no circumstance is it acceptable to eliminate the air space.  I specifically asked about both spray foam and dense packed insulation.  I also asked for a clear answer on whether the vaulted rafter was by definition not an attic assembly since that was the portion of the code that most SF companies are using to justify spraying directly to the sheathing.  The answer was that a vaulted rafter was not an attic, therefore not a conditioned attic assembly.  So now I have the ICC answer.  Those answers may not apply to a true conditioned attic assembly but what I mostly see is the spray foam and dense pack in a vaulted rafter.


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## Gregg Harris (Sep 21, 2012)

RLGA said:
			
		

> The purpose for the venting is to allow the sheathing to dry out from moisture, from water vapor in the air, that has condensed on the underside of the sheathing.  If the foam is closed-cell polyurethane, then the likelihood of moisture reaching the sheathing is almost nil, since closed-cell polyurethane is an excellent water and vapor retarder (low permeability).  Thus, the need to vent between the foam insulation and sheathing is no longer present.
> 
> If the foam is open-cell polyurethane, then it will have a slightly higher vapor permeability than closed-cell, but it is still controlled, so the possibility of moisture reaching and condensing on the sheathing is low if provided in the recommended thickness.  Thus, the need for ventilation is also not necessary.


Does the moisture only come from the conditioned side of the sheathing?


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## RLGA (Sep 21, 2012)

Moisture, obviously, will come from both sides.  The issue is the drying out process--if the wood cannot dryout, then rot and mold will set in.

The roofing membrane will protect the sheathing from liquid water (or it should, hopefully) and the water vapor in the air, if the roof assembly is properly insulated, will not condense on the exterior side of the roof.

On the interior side, water vapor can easily pass through fiberglass blankets and reach the sheathing.  A vapor retarder can be installed to the warm-side of the insulation to prevent water vapor from reaching the sheathing, but the air already within the cavity can still condense and cause problems for the sheathing.  Thus, the venting is required to allow the air to circulate, and if the water vapor does condense on the sheathing, the air circulation will allow the sheathing to dry.

Sprayed polyurethane foams, when properly installed, eliminate the air space completely and provides a barrier that prevents water vapor from reaching the sheathing.  Thus, the venting is not necessary.

However, some roofing manufacturers, such as for asphalt shingles, may not warrant a roof if the insulation is installed directly to the underside of the sheathing for the reason that it builds up heat at the sheathing.  This heat build-up tends to bake the shingles, thus reducing the performance of the roofing.

2009 IRC R806.4 (2012 IRC R806.5) allows the ventilation to be deleted if the insulation is _air-impermeable insulation_.  Air-impermeable insulation is defined by the IRC as having an air permanence of 0.02 L/s-m2 at 75 Pa per ASTM E 2178 or ASTM E 283.  If the insulation meets this, which most sprayed polyurethanes do, then ventilation is not required.


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## mtlogcabin (Sep 21, 2012)

Codeworks

Maybe the problems you saw in the north where caused by moisture being "trapped" between the foam on the underside and the roof covering on the top. I have caught many a carpenter rolling out felt on a wet roof trying to get the house dryed in as quickly as possibleinstallinvetyour


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## Sifu (Sep 21, 2012)

Copied below is the Q&A response from ICC on this issue.  It would seem that code does not permit the air space to be removed if an air impermiable insulation is used in a vaulted, enclosed rafter space.  806.4 refers to an attic space which a vaulted rafter is not.

_September 13, 2012_

_Subject:  06 IRC R806.3_

_Q1:  Without exception Section R806.3 requires a 1" air space between the insulation and the sheathing. Many installers are attempting to install insulation without this space in a vaulted rafter space by using Section R806.4 for a vented attic assembly.  The contention is that the spray foam or the dense packed cellulose is air impermeable as noted in Section 806.4.  Is the rafter space in a vaulted condition (rafter only) considered an attic space, especially in the context of Section R806.4? _

_A1:  First of all, you incorrectly referred to the IBC; your questions should be referring to the 2006 IRC.  Section R202 defines an Attic as “The unfinished space between the ceiling joists of the top story and the roof rafters.”  Section R806.1 requires ventilation for two conditions 1) enclosed attics and 2) enclosed rafter spaces formed where ceilings are applied directly to underside of the roof rafters (vaulted ceiling condition).  _

_The condition you describe is not an attic (no ceiling joists) and shall require ventilation as required for the second condition, vaulted ceiling condition.  I have attached a page from the 2006 IBC to illustrate the intent of the air flow (ventilation) required in a vaulted ceiling condition (see Diagram C)._

_Q2:  Is there any exception to Section R806.3 that would permit the air space to be omitted?_

_A2:  No, the purpose of the air vent is to provide a way to reduce the moisture in the enclosed “attic” space and thereby avoiding the rotting and decay of the wood members caused by the moisture. It is interesting that for a “typical” dwelling of four-family members, the amount of moisture that can accumulate from cooking, laundering, and bathing can be, as much as, 25 pounds of water vapor per day on average, therefore, it is important to have air vents to keep the moisture down._


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## RLGA (Sep 21, 2012)

You are correct that the 2006 IRC does not permit it, but the 2009 and 2012 editions have changed that and now permit the exception in vaulted ceiling conditions when air-impermeable insulation is installed.


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## conarb (Sep 21, 2012)

California still doesn't allow it:



> 2010 CBC R806]*R806.1 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 theentrance of rain or snow.


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## Durant (Sep 22, 2012)

In Codeworks original post he stated " *please, not the thermal barrier quotes and all that bs from the code book,*", and of course was totally ignored.

These new wood chip and glue, foam houses are a shameful example of where this country is going.  They are dangerous to the health and welfare of the inhabitants of the building.  The main problem is that you don't see the problem until after the people living in them have become sick or contracted some form of allergy or other medical problems; and unfortunately that may never be attributed to the real cause which is a sealed box built with toxic materials and called a home.

The "only time will tell" is a poor excuse for allowing these toxic waste dumps to be called homes.  While skilled, trained, knowledgeable tradesmen are a thing of the past and the manufacturers of these toxic products hide behind their installation instructions (which the installers couldn't read if they wanted to) for defense, the American people are being poisoned by their new home.

The ICC, who the governments have given carte blanche to determine what is and isn't acceptable, has sold out to the manufactures of these toxic materials and allows them to lead us in determining what is "good" for our built environment.  The "green" train is running over the health and welfare of the people who have to live in these death cells we call new homes.


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## DRP (Sep 23, 2012)

Sifu, would you mind writing back for an interp of the '09 and '12 codes on this issue? We have been having open cell foam applied to the underside of the roof sheathing without problems thus far.

My Dad was building unvented foam covered plank and beam roof assemblies in the 60's and 70's, there have to my knowledge been no moisture related problems. It was the latest hot tip at the time. We were using foil faced polyiso sheets and applying shingles directly over the foam with 3" roofers, there was no sheathing above the foam, ~r16, times have certainly changed. The problem that did surface was related to the shingles being cooked by the foil facing. He went back and strapped those roofs vertically, sheathed with ply and then reshingled, no problems after that. I've done several of those vented wrap and strap roofs, with much more foam, over the years since.

Mom made us all macrame' belts for our bellbottoms and string ties using pins and scraps of the foam to work on,  we were stylin


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## Francis Vineyard (Sep 23, 2012)

Open cell spray foam applied thick enough becomes air-impermeable; see the manufacturers ESR for specs.

A visual of conditioned attic assemblies: http://www.buildingscience.com/documents/guides-and-manuals/irc-faqs/irc-faq-conditioned-attics/

Understanding attic ventilation: http://www.buildingscience.com/documents/digests/bsd-102-understanding-attic-ventilation

A source of information: http://www.buildingscience.com/search?SearchableText=conditioned+attic

Moisture control for new residential buildings: http://www.buildingscience.com/documents/digests/bsd-012-moisture-control-for-new-residential-buildings/files/bsd-012_moisture_control_new_bldgs.pdf

Francis


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## Sifu (Sep 24, 2012)

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.


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## codeworks (Sep 24, 2012)

thanks much. very interesting info


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## RLGA (Sep 24, 2012)

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.


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## DRP (Sep 24, 2012)

> 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.


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.


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## fatboy (Sep 24, 2012)

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.


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## Sifu (Sep 25, 2012)

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.


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## Sifu (Sep 25, 2012)

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,


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## Francis Vineyard (Sep 25, 2012)

Francis


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## RLGA (Sep 25, 2012)

Interesting...especially the part at the end of the first sentence just before the highlight.


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## Sifu (Sep 26, 2012)

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......


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## GBrackins (Sep 26, 2012)

good thing they only charge by the word for their answers ....


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## rogerpa (Sep 27, 2012)

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."
> 
> ...


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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## conarb (Sep 27, 2012)

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?


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## rogerpa (Sep 27, 2012)

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.


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.


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## conarb (Sep 27, 2012)

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.


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## rogerpa (Sep 27, 2012)

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.


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## Francis Vineyard (Sep 28, 2012)

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


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## DRP (Sep 29, 2012)

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.


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## Sifu (Sep 29, 2012)

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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## Architect1281 (Oct 13, 2012)

I can't wait for the failures to begin... this designer refuses, this inspector approves t the limit of athourity.


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