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question about insulation

As the salesman said an acid salt is used to make the cellulose both flame resistant and vermine proof. While I suppose nearly anything can be harmful, the only health concerns I've heard of regarding cellulose insulation are during the installation of the product--and even then it's mainly because of the dust. Once installed, I believe it's considered quite benign. I've never heard of any off-gassing concerns as are common with other building materials like engineered wood products (from the formaldehyde-containing glue) and carpet.

Remember though that cellulose is literally used to make sponges--thus it can both trap and hold significant amounts of water. While I believe that virtually <I>every</I> home allows some liquid water to penetrate in some conditions, the tendency for such tends to increase with age. Before installing <I>any</I> insulation in the walls, make sure that eaves, flashings, gutters, siding, caulking, etc. are in <B>very good</B> condition! (On the subject of caulking--do NOT caulk below window sills--this is an intentional drainage route for liquid water that penetrates. Caulk below the sills and this water will become trapped rotting the sills and framing.)

I've been enough old gutted homes during rainstorms to know that even "decent looking" shells leak some water and "typical" shells can leak quite a lot. As long as the walls remain uninsulated and somewhat drafty (also common), the water will evaporate and there won't be any permanent damage unless the leaks are severe. Add insulation (especially cellulose or fiberglass) and water that was insufficient to cause a problem before can easily become trapped and build to the point that it causes severe and costly damage.

As Brad White mentioned, the cavities in the corners of balloon-framed homes are virtually inaccessible and frequently quite drafty. The only practical way to insulate them is with expanding foam.

Comments

  • johnnyge
    johnnyge Member Posts: 86
    question about insulation

    I have to insulate my old house (about 100 years old ballom construction).I am getting quotes for a few insulators company but I need an oppinion. Which one is better the Spray Foam insulation or the other one that is made out of paper(forgot what it is call).Also from the 2 types how they messure the R Value.
  • Chris S
    Chris S Member Posts: 177
    insulation

    We have had success with sprayed foam/ fiberglass combination. I like it beacuse it stops drafts- especially around electric boxes & penetrations. I believe that R value is not everything- inattention to detail ( drafts ) can kill an otherwise well constructed job.
    I don't see the cellulose type products offering that type of protection. Also- just as with fiberglass the installer ( spray applicators ) skill & experience is important
    Good Luck
    Chris

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  • Brad White
    Brad White Member Posts: 2,398
    Depends on how you go about it...

    I too have a balloon framed house, about 135 years old so not unlike yours.

    In the 1980's I had short-fiber fiberglass blown in (CertainTeed Insulsafe II). It packed well as evident by renovating the second floor 15 years after it was installed. It held in place like a thick white wool blanket and I retained most of it.

    That said, today, I would use dense-pack cellulose in a blown in application as it makes a decent air stop according to the literature. I have no direct knowledge to back that up but am about to do a few blower door tests on homes before and after the application so we shall see.

    When insulating a balloon frame house, I would at least use foam in the end joist bays where the stud cavities may be open to the joist bays. Seal them off. I found piles of blown-in fiberglass above ceilings because the gaps were not blocked off.

    Now, the foams: Icynene has almost a market lock in that most people use the term to describe nearly any foam product. Sort of like "Kleenex" or "Band-Aid".

    What I like about Icynene (from an engineering perspective) is that like all foams it is a superior air barrier. It fills the cavity and has high integrity. The R value is about the same as fiberglass batts but it has a higher integrity of that R value of that makes sense. (Batts with even slight gaps can lose a lot of the value to air circulation.)

    Where I find that Icynene falls short is in vapor transmission compared to the urethane foams. Perm ratings ar in the 6 to 9 range if I recall correctly. The urethanes have double the R-value (in the 6 to 7 range per inch) and have low perm ratings (below 1.0) in thicknesses over a five inches.

    All foams need to be sprayed on in layers under 3 to 4 inches so that they do not combust from endothermic heat.

    Here is where I shy away from foams in a blow-in application: Despite some claims that the foams can be injected into the walls, a dealer told me that they would not do that; that it could bulge out the walls and make a huge mess. Surface spray after stripping the interior? Another matter. If that is the case I would use foam in a heartbeat.
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"



    -Ernie White, my Dad
  • JohnG_3
    JohnG_3 Member Posts: 57
    We used cellulose

    I got estimates for cellulose and Icynene. Icynene, while very good, is also about two or three times the cost of cellulose. I also heard some anecdotal stories about it getting everywhere, i.e coming through even small holes in the walls. The R-values were not significantly different, but as the previous post mentioned, Icynene does a much better job at air sealing. In the end I thought cellulose would be a slightly more practical choice for a retrofit application like mine. I am planning on doing some renovation in which the walls will be opened and will probably use Icynene for that project.
  • johnnyge
    johnnyge Member Posts: 86


    How safe is that cellulose. I had two estimates done on the insulation of my old house. I am not going to discuss price as per teh rule on this web.
    The first one is spray foam on the outside walls only
    The second is with cellullose, but in this estimate is insulation all over the house meaning outside walls, in joist between floors, tiger foam on sill plate on the basement, attic ceiling in other words everything.
    The salesman said that cellulose is safe, has a fire retardant value, doesnt attract insects or rodents because some acid on the product, noise reduccion. He sound very convincing. The different in price is about a 1000 more. What is the Wallies imput on this project.
  • johnnyge
    johnnyge Member Posts: 86


    How safe is that cellulose. I had two estimates done on the insulation of my old house. I am not going to discuss price as per teh rule on this web.
    The first one is spray foam on the outside walls only
    The second is with cellullose, but in this estimate is insulation all over the house meaning outside walls, in joist between floors, tiger foam on sill plate on the basement, attic ceiling in other words everything.
    The salesman said that cellulose is safe, has a fire retardant value, doesnt attract insects or rodents because some acid on the product, noise reduccion. He sound very convincing. The different in price is about a 1000 more. What is the Wallies imput on this project.
  • foam insulation

    Many of the projects I do use Icynene spray foam and it is an amazing product. Don't be fooled by the Rvalue issues. Foam prevents infiltration and that feature is the key to a warm ,comfortable, efficient home

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    JIm Patterson- OVHC
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