Your opinion--Best insulation

Discussion in 'Homesteading Questions' started by mamabear, Dec 7, 2005.

  1. mamabear

    mamabear Well-Known Member

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    In new home construction, there seems to be an endless list of insulation choices. In your opinion, which would you choose? :shrug:
    Thank you for your input.
    mamabear
     
  2. romancemelisa

    romancemelisa Well-Known Member

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    This is one place we would not skimp, it will pay for itself in the long run. I'd have to run up to the house to see what we used (maybe later), it is pre-wrapped with a vapor barrier and is not itchy like fiberglass, I believe it was a r-30, and it came from Lowes.
     

  3. cindyc

    cindyc Well-Known Member

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    look up bale houses. Dept. of energy gives this a R-50 (!!!) insulation value and it is WAY less expensive than regular insulation. Also, it is a natural substance with no fiberglass or other bad stuff in it for you to breath.

    If you don't want a completely different building method, I hear cellulose is very good.
     
  4. Alex

    Alex Well-Known Member

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    I think the amount of insulation is important. Then you can put in whatever is cheapest or whatever you want -- this could depend on many construction details -- too many.

    Hers is a link to DOE insulation recommendation .

    Of course you can go even more than this amount. But there is a point of diminishing returns. Still, if you are thinking long term and consider the relative costs of energy will increase more than the investment in insulation, then you may want more.

    Or, you may just want a building with very low energy loss or gain -- sort of like when you want granite counter tops instead of tile or Formica -- you just want it -- and will get it -- and the cost, or life-expectancy of the product are not the issue.

    Get insulation and burn less wood,

    Alex
     
  5. BigBoy

    BigBoy No attitude here...

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    Personally, I like this. http://www.tigerfoam.com/ No experience using it but anything has to be better than sagging, itchy fiberglass. Icynene is a similar (or maybe the same) type of insulation.
     
  6. Cyngbaeld

    Cyngbaeld In Remembrance Supporter

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  7. stanb999

    stanb999 Well-Known Member

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    If I were building a new home I'd go with SIP construction. They are structural insulated panels. They form your outside walls. The average wall r value is 19 but you can specify more. Also unlike other types of insulated wall systems they dont have the cold infiltration at the studs. Wood has an r value like 1 per inch so if you have a stud every 16" your R19 is more like r16 and it's worse if you use 2X4 studs that would be more like r10 instead of the listed r13 value.

    Insulation value is about two things

    Air infiltration
    resistance to thermal transfer.

    The modern construction methods do much better in regards to both of the conditions noted above. So in reality use what you like.

    P.S. Those big windows cost you the most heat/cooling. So for a truly effient home limit them to the minimum. Also limit the hight of your ceiling in cold ares and maximize it in warm ares.
     
  8. kuriakos

    kuriakos Well-Known Member

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    Spray-in foam insulation is great...all the brands I know of, anyway. Wet-blown cellulose is also good, and usually quite a bit cheaper than the foam.

    Fiberglass is the worst insulation ever invented. Most still has formaldehyde as a binder, which outgasses into your living space. And air goes right through the stuff...think about, furnace filters are made out of fiberglass because air goes through it so well. R-19 fiberglass is a LOT less efficient than R-19 sprayed-in-place foam.
     
  9. SolarGary

    SolarGary Well-Known Member

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    Hi,

    It seems to me that SIPs offer the most foolproof way to get good insulation values and low air ifiltration. They also eliminate a lot of the thermal bridging that you get with stud walls that are insulated between the studs. I am told that going to thicker SIPs does not have dramatic impact on cost -- this would be something to consider. You still need to worry about sealing the floor to wall and wall to ceiling joints well (see link at bottom).

    Foam in place insulation gives good R values and also basically eliminates air infiltration. The R value per inch is high, so you get good R values in walls that are not overly thick. But, you do get the thermal bridging from the studs.

    Some of the good builders around here (Montana) are using 2X6 walls with studs on 24 inch spacing. They foam in place about 2 inches -- this provides a total barrier to air infiltration. Then they fill the rest of the cavity with conventional insulation. This is cheaper than filling the entire wall cavity with foam in place insulation, and still gives zero air infiltration through the walls.

    If you use conventional insulation, I think that Cellulose is better than fiberglass -- better R value and more resistance to airflow through the insulation. But, if you do use conventional insulation, you need to take great pains to have a good and complete vapor barrier on the inside, and a good and complete air infiltration barrier (that is still vapor permeable) on the outside. Very careful installation of the insulation (rare), and sealing all the plumbing and wiring penetrations.
    I think that this publication from Soutface.org covers most of what needs to be sealed -- its a lot:
    http://www.builditsolar.com/Projects/Conservation/Southface8_airsealing.pdf

    Strawbale construction may also be a good path. The books make it sound very good, and some people report good results. Maybe worth looking into more.

    In the end, a lot depends on what kind of insulation you use, but a lot also depends on the quality of the job thats done.

    Gary
    www.BuildItSolar.com
     
  10. JAK

    JAK Well-Known Member

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    Lots of details to consider like Alex says.

    Some areas are easier to insulate than others, and some areas are more important than others. Details like where the roof meets the walls, and where the floor joists sit on the foundation wall, and how windows are insulated at night are very important details that need to be worked out in the earliest stages of design when you are deciding on building materials and construction methods. The climate and topography of the site, and the availability of insulation and building materials to the site, all need to be considered together when you decide what type of house you want to live in. Whether it is lightly built like a Yurt or a Japanese home, or massively built like a cordwood or strawbale or earth shelter home, there should be some sense of reason, such that a thoughtful solution is also a beautiful one. At the end of the day you want to live in a dwelling, not a building.

    In a cold climate, passive solar heat is best if you have a site with a good view to the south that you want to make use of. Such windows should be vertical and directly South so they make good use of the sun in winter without overheating the home in summer. Windows are still expensive however, and the sun only shines strong for 6 hours, so it is best to glaze no more than 50% of the South face so that you have a practical means of insulating the windows at night. Also, you still need an excellent view to justify all the trouble.

    If you are integrating a greenhouse into your home in a cold climate insulating the glazing at night is more difficult because the glazing approaches 100% coverage and may even be slated overhead. It can be done, but whatever solution you come up with will be a dominant feature in your home, and should not appear to be an afterthought. It should not appear to be so expensive that the growing of vegetables or the treatment of greywater in such a space seems impractical. It is best if that which is most practical reveals itself before you build that which is least practical.
     
  11. foxtrapper

    foxtrapper Well-Known Member Supporter

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    Formaldehyde is in the foams, not in fiberglass.

    I've got foam because my house was built a century before the insulation. It's not what it's cracked up to be. Makes running wires sheer hell. It does shrink, it doesn't expand everywhere, and lots of areas are missed. It's nowhere near as vermin proof as claimed. It's, ah, "fun" figuring out what type of foam you want to use.

    Cellulose packs down over time. Mice and rats *love* to tunnel in it.

    Fiberglass sure is easy to work with. You can run wires later, upgrade it in the attic and basement, etc. Of them all, I like fiberglass the best. But you can't stuff it into a wall after the house is built.
     
  12. hisenthlay

    hisenthlay a.k.a. hyzenthlay

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    I'm not particularly knowledgable in this area like some of the posters are, but I wanted to add that we just insulated the attic of our 100 year old leaky house with that spray in dry shredded paper stuff (edited to add: it's cellulose--cocoon brand)and it's done absolute wonders. We kind of went overboard and sprayed in about R-49 worth of the stuff, but the difference in the house is amazing. When it was 50 degrees out, the heaters were always on and the house was still cold. It was 10 degrees this morning and the heaters were off but the house was toasty. There is no other insulation in the house. The whole job cost less than $200, we did it ourselves, and we've probably already saved that much in heating bills. Seems like a good deal.

    Good luck with your new house.
     
  13. SolarGary

    SolarGary Well-Known Member

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    Hi,
    I think you are talking about the old Urea Formaldehyde foam in place insulation that was retorfited to many homes. This type of foam did have a lot of problems. To the best of my knowledge, it is no longer legal, and no one is using it. The new type of foam is really for new construction only.

    The new foams are Polyurethane based -- they are very good. High R values, no shrinkage, and they completely eliminate air infiltration, which can be a major source of heat loss. They do make retrofitting wires in outside walls more difficult, but that seems a small price to pay for the good performance.
    Celluose (and loose fill fiberglass) do settle some over time, but this is included in the original R value specification. I've never seen anything that showed that mice and rats are any more of a problem in Cellulose than they are in fiberglass -- it would be interesting to see if someone could find some good data on this. We have Cellulose in the attic, and live in an area with plenty of mice -- I've never seen any evidence of mice activity in the insulation -- maybe others have had different experience?

    The thing I like about Cellulose over fiberglass is that it has quite a bit of resistance to air currents flowing through the insulation. The effectivness of fiberglass can be reduced significantly by these air currents. In walls Cellulose does a better job of filling the stud cavities -- fiberglass bats tend to leave gaps on the edges unless installed with extreme care.

    Gary
    www.BuildItSolar.com
     
  14. gccrook

    gccrook Well-Known Member

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    Don't know about cellulose, but I can vouch for the fact that mice will use fiberglass, as I just took a couple of walls down that had fiberglass insualtion, and there was ample evidence of mice, including interesting little tunnels in the insulation. If sprayed in foam has formaldehyde, then all the manufacturers are lying outright, as they are very quick to point out that they do not have any in their product. Based on a few people I have talked to that have had the sprayed in foam in their houses in the last 5 0r 6 years, they are extremely happy with it's performance. I will be getting an estimate soon, for our new addition, so I will have a better idea of the cost difference.
     
  15. mtman

    mtman Well-Known Member

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    i like fiberglass with the foam you have to watch in a older home it will find every crack and can even move loose boards
     
  16. Ed K

    Ed K Well-Known Member

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    We uses Icanene (like BIG BOY suggested) in our new home and are very pleased. As stated above it has the added benifit of stopping infiltration in addition to it's straight R value. Some of it is covered with drywall but in the attic ceiling it's still exposed. No cracking after over a year.

    I think it's great.
     
  17. kuriakos

    kuriakos Well-Known Member

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    SolarGary is right, there aren't any spray-in foams with formaldehyde anymore. And I think fiberglass batts still have formaldehyde unless you pay a lot more for the formaldehyde-free kind...I could be wrong about that, though. But the modern polyurethane-based foams are much better than the old urea-based foams for new construction. I wouldn't use anything else if I ever build another house.

    There's also a "slow-rise" pour-in type that you can use in existing homes without tearing all the walls down. You just drill a hole near the top of each stud cavity and put the nozzle in and shoot some foam in, let it expand, then repeat until the cavity is full. It expands a lot more slowly than the normal kind so it rises to fill the cavity instead of bulging outward and pushing your walls off the studs.
     
  18. mamabear

    mamabear Well-Known Member

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    Hi folks! Thanks for the suggestions. Our house is going to be wood frame (2 x 6 exterior walls). We had recently seen a program on HGTV where they insulated with the spray foam insulation and I was intrigued. We've used it for small things. You know the kind that comes in a can? But I didn't know that they made it for big jobs. I was really impressed with how it filled into all the areas. I was wondering if anyone else on here had used it and I am pleased to hear the results of those that have.
    I didn't want to mention this particular insulation in my original post as I did not want to influence any answers. I always know I can count on y'all for help. As we get closer to building, and actually start, I hope that I can continue to turn to y'all for support.
    Love y'all bunches.
    mamabear
     
  19. fernando

    fernando Well-Known Member

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    Any suggestions regarding finding a way to have foam sprayed in at a reasonable price ?
     
  20. ET1 SS

    ET1 SS zone 5 - riverfrontage Supporter

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    Your link took me to Owens corning NOT the DOE.

    Just thought you should know.

    :)