Some of you may remember me hanging out here a few years ago.  I decided to go with trusses and foam on my project instead of SIPs and I don't come to this site as much. I am going through an experience right now that may be of interest to the SIP vs. Foamed Truss questions that come up here frequently.

On my first project, I put in trusses and closed cell foam against the roof deck.  I weighed all the downsides (shingle warranty issues, rot issues, etc.) and sprayed it.  It was an ASTM E-84 fire rated foam and met the code insulation requirements without a fire barrier.  My county inspector signed off on it.

Then, I built my house.  It has 2x8 rafters, again, because the cost and engineering on SIPs was higher.  It also has an unvented attic with foam applied under the roof deck.  And I now have a different inspector.  He says foam won't work and so I have an appointment with his supervisor.  One problem is, the upstairs bedrooms in the house have knee walls and the 2x8 rafters won't allow enough junky fiberglass insulation to meet code. (see the picture)  The inspector's solution was to fir out the rafters a few more inches (then my casement windows won't open completely!!)

Here are the objections (to date)
1) The Washington Energy Code requires that the insulation be in "substantial contact" with the "heated surface."  Even though the attic is conditioned space, he considers the bedroom ceiling drywall the heated surface.  The insulation will against the drywall part of the way, but then up on the roof deck in the peak.  I consider the bottom of the foam insulation to be the heated surface in a conditioned attic.  I asked him if the county had ever approved a foamed roof deck.  He said that the only one he was aware of had to be torn out to meet the county's interpretation of the code.
2) Foam insulation would promote roof rot by not allowing air to the roof deck.  He wants me to put foam panels or fiberglass battens on the ceiling.  Problem is, it's an ICF house with concrete gables.  I don't have any vented bird blocks and don't want to drill through insulated concrete to put in gable end vents.
3) Shingle warranty.  You've all seen this one around, but I wasn't aware that the building department cared.  It appears that my product has a warrantyfor an unvented application in Canada , but is silent about it in the U.S.  I don't care one way or the other.  I'll take $5,000 in energy savings and have my roof wear out 6 months early.
4) Fire protection of the exposed foam in the little attic area.  This is where we started out (he thought up the other objections later).  Several of the spray foams have recently received ICC ES reports that allow attic applications in certain situations without a fire barrier so long as it is separated from the living areas by drywall.  I sent him the reports.  He remains unconvinced and what he says goes.  Because of my design, the "attic" is a 5 foot triangle at just the peak of the house.  I would have to remove all foam that is proud of the 2x8 rafters in order to have a nail base for drywall.  That would reduce my R value right where I can really use it in this design.  Then, I would have to thread slices of drywall up through the collar ties and attach them in a tiny space that I will probably never enter again.

It's not settled yet what I'm going to have to do.  The purpose of this post is just to warn people that switching from SIPs to foamed trusses or rafters may not be as easy as thought.  Talk to the county first.  Of course, it's possible that, had I built with SIPs, the county would be just as confused.

Mark

Mark;

Nice looking job

I just got back from my meeting with the head of the building inspection department.  Over an hour, so they gave me plenty of time.  But guess which point seemed to trouble them the most?  The shingles and whether foamed insulation voided my warranty.

As an attorney, I know warrantys.  If I get a million mile warranty with a used car, it doesn't make the car safer, better, more fire resistant, etc.  The warranty is just a contract between myself and the seller.  I can say "no thanks" to any warranty.  If the warranty requires the dealership to do periodic tuneups, I can chose not to, and get better and cheaper service elsewhere.  Warrantys are just a market driven commodity that are generally loosely associated with the quality of the product, if there's any connection at all.  On the shingles, it's the quality of the materials and the quality of the installation that's important.

Couldn't get the county to agree.  They felt that the product had to be installed according to the manufacturer in order to meet code.  Fine.  My roof is.  But they felt that anything that voids the warranty proves that it is an improper installation.  An unvented attic, although allowed by code, might effect the longevity of the shingle.  But not the fire rating, the structure, i.e., the items that the building department should be concerned with.  Since when are they concerned with whether it's a 20 year shingle or a 40 year shingle?

They want to see my warranty.  I didn't get one.  I bought the shingles probably in 2003 from a place in Canada.  I know that if I really wanted to press it, I could claim that I should have been provided with a warranty.  It's possible that the price I negotiated was for shingles without a warranty (the company's warranty states that pricing is available without a warranty).  It's a big name manufacturer, so I can find copies of the warrantys on line.  And I do mean warranties, plural.

I haven't been able to find a warranty from 2003 (To make things more complicated, this shingle was discontinued in about 2007).   I've found 2007 and 2008 warranties, and they do differ.  In Canada, the company's shingles are presently not warrantied on a roof that doesn't meet code specifications for ventilation.  The IRC allows an unvented roof, but maybe they mean it has to meet code for a vented roof.  In the U.S., the warranty period is reduced for a shingle used on an unvented roof.  So, if I have a warranty at all, and it isn't an earlier version that's no longer available on the web, and it's the U.S. warranty, then what does that say to the building inspector?  It should say that he's barking up the wrong tree, but I haven't had much luck with that argument. 

So, what does this have to do with SIPs?  Suppose I had my SIP roof on and put these shingles on.  That doesn't meet code according the my Building Inspector's "logic."  Fortunately for SIP builders, the BI probably never thinks of this "argument."  What would be the remedy?  Tear off the SIPs?  Nah, that's foolish.  Put a layer of Elk shingles over the "voided warranty" shingles?  Nah, that's foolish.

As a general rule, when the solutions are foolish, it's likely that the problem is as well.

Does anybody really keep track of which roofing was and is warranted on SIPs?  Full warranty, limited warranty, reduced warranty?  Should it matter to the building department?

Mark

Mark,

I could quote IRC but it is the unfortunate truth that local jurisdictions will often times supercede the national building codes.  That said, I agree that building inspectors are not responsible for warranty issues.  A "properly installed" shingle is no more a code issue than a poorly constructed basement, and we have ALL seen at least one of those.  I've seen inspectors pass buildings with wet basements and simply note that "the owner should contact GC to rectify standing water in basement" ..."house passes for occupancy with the above items noted."

So I guess I'm on your side, but that is of little help to you.  Do I disagree with the practice of your inspector ?  YES  Do I deal with similar issues on an almast day-to-day basis ? YES  Have I figured-out how to guess what an inspector might think of next ?  NO

I can quote one portion of the Building Code that may be where the inspector is refering....."all materials should be installed in accordance with manufacturer's suggestions, and in keeping with general construction practices."  Unfortunately,
no one seems to consider the ever-evolving construction methods that are being introduced and this often creates a very lconfused inspector.

Good Luck !

It gets better. 

On the day my request for an unvented roof assembly was denied, the Washington Code Counsel met.  The had previously held public hearings on unvented roofs, but had tabled a pending motion to allow unvented roofs and change several aspects of the building code.  I has spoken with the Counsel Director and was told last Monday that the issue would not come up again until next year.

Come to find out, they decided to vote on it last Thursday.  It passed.  Unvented roof assemblies will be allowed under the Washington Energy Code and the Washington Building Code starting June 1 of 2010.  I told my building official and he agreed to review my request in further detail even though the provision isn't active for a year.  One step forward 9/10ths step back, repeat.  I might be making progress.  Probably not.  Can't get my hopes up.

Even with unvented attics being permitted by code, a local official can easily find a way to deny its use.  Say for instance, with the shingle warranty "issue."  I sent the building department a statement from IKO about the difference between building codes and product warranties prior to their denial.  The statement reads:

The Code requirements are legal regulations related to product/building performance, and are designed to ensure quality construction and occupant safety.  Manufacturer's limited warranties are offered to our customers and define various aspects of contractural obligations regarding product warranty coverage.  Building codes cannot legislate or mandate levels of limited warranty coverage, as these "contracts" are a matter between the purchaser and seller/manufacturer of a material. . . Unfortunately this is not the first time that prescriptive building code requirements have been confused with manufacturer's limited material warranties.

Can't get much clearer than that.

I called a local SIP company and explained my situation.  He groaned and said they had done a few "end arounds" over the years to satisfy buiding departments.  He also said that he would be glad to look at my plans and give me some advice.

Mark

Mark;

Every one has a boss, it has been my experience hat you need to move up the political food chain.
Contact a council person in your district to apply pressure to the building department head. let them explain why they have taken it upon themselves to be the warranty Czars, instead of enforcing the code, which is their job. Somewhere along the line these building officials loose sight that they are supposed to be public servants, not road blocks