Replies

1. 
   dIrishInMe | Feb 08, 2004 07:02am | #1

   Generally, a subcontractor is responsible for his work to pass inspection... If it doesn't, his work is considered defective...

   I'm gonna guess though that the return trip got into your wallet a bit...
    

   Matt
1. 
   sailracer | Feb 09, 2004 03:49am | #8

   Not my wallet.  I don't pay subcontractors I have never worked with until I get approval.

2. 
   CloudHidden | Feb 08, 2004 08:06am | #2

   http://www.wisconsinpublicservice.com/business/bs_02.asp

   Look toward the chart at the bottom...about diminishing returns. The first inch of insulation does the most, the next a little less, and so on. While it's improper to say that anything over X inches is wasted, it would be equally improper to just focus on R value. With polyurethane foam, 3 inches provides something like 97% effectiveness, while 4" gets you to 98-something. Can't find my chart with the exact numbers. Is the 4th inch worthwhile? Depends on budget, climate, etc. It's certainly not wasted, but it might not be as cost effective in some cases as in others. Always a trick to convince inspectors to look beyond raw R values, despite how they don't tell the complete story.

1. 
   fortdh | Feb 08, 2004 09:25am | #3

   Cloud, you are correct. I heard many foam manufacturers in Vegas complain that they can't get codes to accept that x inches of type A foam was as effective as some R-value of type B insulation. In reality, I believe the foamers, and r-21 of 3" of polyurethane closed cell is probably worth all or more of an R-30 installation of fg. It is going to have to be won by the foam industry so that the inspector has a code acceptance. I once got a variance on a foam board applied to block foundation wall that had the blocks foam filled in lieu of under floor insulation, but it was hard sell. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   AndyEngel | Feb 09, 2004 08:34pm | #9

   Huh. Do you think there's a reason that chart isn't printed on every bag of insulation sold?Arguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.

1. 
   CloudHidden | Feb 09, 2004 09:40pm | #10

   Yeah, isn't that a neat chart. Can't think of anywhere it could be printed though, can you?

   The subject is fascinating to me. Ever since I got into thin-shells, I've been taught that each inch of foam gets you closer to the mythical 100% effectiveness, but not proportionally, and at some point it's not worth the extra money--you won't ever save enough on energy bills to pay the financing costs for that extra inch of insulation.

   Really hasn't hit me like it did with this chart that simply adding the R's is misleading. Yet that's how the codes work, and it's a bear sometimes to get our 3" foam walls with 0 air infiltration through the energy worksheets that require R31 in ceilings, etc. Yet, as Oak Ridge's mass wall studies show, that assembly is demonstrably superior.

   You and I have talked about Oak Ridge before, and their whole wall assembly studies are why I like them so much. The R of any individual component in a wall is almost meaningless. What really counts is the effectiveness of the whole system.

   I wonder if there's room for THAT on each bag of the pink? :)

1. 
   AndyEngel | Feb 09, 2004 10:23pm | #11

   I've attended several conferences on home energy use, and the concept of whole house performance is well understood by that segment of the industry. But that's where it stops, with probably the top 5%. There is so much about heat loss in houses that isn't intuitive that insulation contractors should be the best educated people working on a house. Is that how it is where you live?

   Arguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.

1. 
   fortdh | Feb 09, 2004 10:29pm | #12

   Andy,

   Had an insulation contractor say to me in Dallas, Texas,"you really don't need any insulation here, it doesn't get very cold, ya know". It was 110 at the time. Yup, right there on the cutting edge...PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   CloudHidden | Feb 09, 2004 11:49pm | #13

   >There is so much about heat loss in houses that isn't intuitive that insulation contractors should be the best educated people working on a house. Is that how it is where you live?

   My most up-to-date subs were in HVAC. But in other locales they're the most resistant to new stuff.

   Currently I'm running into a lot of "we'll do it that way be/c that's how we do it" from contractors. That covers things like me wanting to specify California Closets instead of rods and one shelf, RFH instead of forced air, GSHP instead of heat pump, structured wiring, any automation, and the list goes on.

3. 
   AndyEngel | Feb 10, 2004 12:22am | #14

   I'm thinking there might be money to be made by being the contractor who says, "Yeah, I can learn how to do that. It's gonna cost you, though." But I've never been one for ruts.Arguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.

3. 
   ubeexacto | Jan 12, 2012 10:50am | #15

   Icynene chart

   cloudhidden - Could you tell me where I could find this chart you are referring to?

1. 
   xxPaulCPxx | Jan 12, 2012 12:54pm | #16

   Diminishing returns on R value

   Here is a link to the chart and an explination:

   http://www.buildings.com/ArticleDetails/tabid/3334/Default.aspx?ArticleID=6061#top

   Basicly what they are saying is that insulation has a set price per inch... for foil faced foam it's about $1 per square foot for an inch of R6 insulation.

   $1 = 1" = R6

   $2 = 2" = R12

   $3 = 3" = R18

   $5 = 5" = R30

   $10 = 10" = R60 

   The kicker here is that depending on your climate, there is a point where more R value doesn't make you any more cozy.

   For instance, in my climate R30 is called for.  Right now my attic has R13 between the joists (I'm currently going for R30 in a roof project).  R30 makes sense for my climate because it's not very hot nor very cold where I live.  Instead of spending $5000 on R30, I could spend $10,000 on R60... but I wouldn't actually feel and difference.  And the HVAC savings due to the added insulation?  Pennies.  The first R30 saves me hundreds of dollars, the next R30 saves me pennies.

3. 
   dIrishInMe | Feb 08, 2004 06:55pm | #4

   Doesn't help your situation but another thought for all the "readers" here is that this situation underscores the fact that whenever you are using a construction technique that is not commonly used in your area, it's just about a requirement to talk to your local building inspection office to get their buy-in *prior* to taking the plunge... 

   My experience with building inspectors is that there is often room for negotiation before the work is done, but once they write out that pink slip, that's it.  They ain't gonna back down, and their bosses will back them up.
     

   Matt
1. 
   fortdh | Feb 08, 2004 11:11pm | #5

   Matt, agree 100%, and every time I have asked inspectors for their input, they have been willing, helpful and cooperative, and the work gets passed. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

4. 
   Piffin | Feb 08, 2004 11:21pm | #6

   Skipper,

   I took the "Walls that work" course from AIA and Corbond which is a competing spray foam insulation. Theirs is about R5 to R7 while the ICY is only R3.5 or thereabouts so much of the Corbond research does not apply directly. but they have much available on their website.

   http://www.corbond.com/news.asp

   Part of the therory in the equivalency is that if the entire buildiung envelope is foamed, the convection leaks are stopped and the performance increases drasticly. The lost BTUs with fibreglas insulation triples in cold weather and wind, while the heat loss through a complete Corbond package barely changes. I think it is only something like a 20% change at -25°F with a 15MPH wind for the Corbond.

   Now, if you only have the spray foam in the ceiling and the walls are still fibreglass and nothing sealed at the rim joist on sill, then the building officilas are right. You've got some pretty good insulation in the ceiling but still experiencing the infiltration that makes for most heat loss.

   Hope this helps.

   I do agree that anything the installers tell you, they should be able to back it up with printed verifiable findings. Corbond does that and has been winning their way gradually with codes departments across the country.

     

    

   Welcome to the

   Taunton University of Knowledge FHB Campus at Breaktime.

   where ... Excellence is its own reward!

    

1. 
   Piffin | Feb 08, 2004 11:23pm | #7

   http://www.corbond.com/news.asp?file=research  

    

   Welcome to the

   Taunton University of Knowledge FHB Campus at Breaktime.

   where ... Excellence is its own reward!