We take a look at a house that has both blown cellulose and fiberglass insulation.

25 Responses to “insulation cellulose over batts”

  1. anotherheist July 6, 2010 at 11:31 am #

    blown fbg has an r2.2 to 2.6 and cellulose is a 3.7 ish, plus fbg isnt a dense product so it doesnt stop all air movement in the walls like cellulose, i blow both products for over 20 years now and cellulose is much better when installed right, just my opinion,ur not talking about teh cubed stuff are you?tht stffi junk

  2. Dan Post July 6, 2010 at 12:31 pm #

    The reality is Blown in BLanket according to industry standards gives you an R4.1 per Inch making a 2X4 which 3.5/8″ R15 and Cellulose at 3.7 per inch a R14 this documented

  3. indyswift October 4, 2010 at 8:47 am #

    Fibreglass batts tend to break down over time, they provide a smaller long term value than cellulose insulation.

  4. cavibird2005 December 8, 2010 at 1:38 am #

    Who Batted this place?? Fluffy not Stuffy Boys! And if you split you batts and Chink gaps you’ll get damn near whatever your batts r value is.

    Cellulose is a pain to work with and while its cheap will never perform the way bib fiberglass does.

  5. Doug Cumpson December 28, 2010 at 7:19 pm #

    Contrary to some people – it is in the best interest to have a vapor barrier of not less than 6 mm on the interior walls of all buildings.

    There is no evidence to suggest a vapor barrier enhances moisture – in fact quite the opposite is true – the vapor barrier acts as a barrier to moisture.

    Arguably all insulation should be installed with a vapor barrier on both sides of the insulation effectively wrapping the insulation like a sandwich bag making the insulation air tight.

  6. Doug Cumpson December 28, 2010 at 7:24 pm #

    There is no evidence that plastic vapor barrier is the cause of moisture accumulation or mold – in fact it is the opposite – the vapor barrier keeps moisture or mold from penetrating into the home – it is the lack of vapor barriers that traps moisture in the insulation. Batt insulation should be completely wrapped to keep the toxic chemicals from penetrating into the home. The best alternative is Eco – friendly foam insulation as it develops its own vapor barrier.

  7. cotequadsport February 15, 2011 at 3:32 pm #

    in my opninion, cellulose is better.fiberglass allows air to move threw it. the R value is not a TRUE R value, it attracts pest and will eventually leave gaps between rafters.cellulose uses borax in there product to keep pest awa. cllulose has a TRUE R value of 3.4 per inch( atleast from national fiber). in my area (maine) code for an attic is an R49. 15 inches leaves an attic with an r value of 51. now the down side of cellulose is, remodels,now have a useless aticc( unles built up), its messy

  8. hagenar April 5, 2011 at 9:10 am #

    ATTENTION, people in northern states, Canada, Sweden etc…
    It should be noted that adding an internal vapor barrier is important for colder climates. Builders should check local codes and standards before following arosonna’s advice to omit it.
    In areas that experience real winter, a well sealed internal 6 mil plastic barrier will help stop your wall cavities from turning moldy and soggy. A breathable wrap is still ideal for the outside.

  9. VerumAdNauseam April 5, 2011 at 6:46 pm #

    Fiberglass is torture, I won’t bring it anywhere near me.

  10. VerumAdNauseam April 5, 2011 at 6:46 pm #

    Fiberglass is torture, I won’t bring it anywhere near me.

  11. homesinsulation July 29, 2011 at 8:45 pm #

    Fibreglass batts tend to break down over time, they provide a smaller long term value than cellulose insulation.

  12. cotequadsport September 1, 2011 at 12:02 am #

    good job with this video. that fiberglass always has gaps and also allow airs to move threw it.

  13. Gina Musso October 11, 2011 at 11:31 am #

    these comments show that you’ll never get the same answer to the same question.

  14. luvthisoldhome November 1, 2011 at 7:47 am #

    i did a fair amount of research and decided to go with blown fiberglass for my home. i saw some things online that made me go this route. 1. cellulose is shredded paper- with an old wood home not going this route. 2. cellulose will retain water, so if you ever have a leak you will have soggy, wet, molding paper 3. cellulose could have ink and possibly mold from the start 3. cellulose if ever gets wet could lose its fire proof properties.
    blown fiberglass- for me!

  15. zzhamstring November 2, 2011 at 9:49 pm #

    To me you sound knowledgable with what you’re talking about. I have a question to ask?

    I’m new homeowner of townhouse condo and I paid a visit to my attic and notice that I have cellulose insulation on a flat floor with no joists.From that draft that i felt it appears that my roof is not well sealed from the inside. Now if I go into the attic to try to cauk, I’ll be stirring up the celliulose.What are my options?

  16. honeybeerancher May 20, 2012 at 4:47 pm #

    Sound like your biased and you might be working for a cellulose company.

  17. Typpendahl August 19, 2012 at 5:03 am #

    Touche! Great vid, thanks for sharing.

  18. formerevolutionist August 28, 2012 at 4:05 pm #

    Cellulose has a much higher R value than fiberglass. It is also a better sound insulator. You can play loud music in one room and the people in the other room will not hear it very well.

    I think the contractor should have taken the cellulose he shaved off the wall and put it in the attic after the drywall has been put in. That would have saved time and trouble and also would be a better insulator. That’s the way my boss did it when I was younger and it worked well.

  19. Hotpaper November 8, 2012 at 5:13 pm #

    Rigtig god video, rigtigt pænt lavet

  20. eastsidepsycho December 6, 2012 at 1:38 am #

    Exterior walls are wet sprayed

  21. M Rashid January 24, 2013 at 11:05 am #

    Why not rockwool/stonewool? fiberglass might be a health risk?

  22. mark marcelis February 18, 2013 at 1:08 am #

    a lot of the blown wool came from MONTANA AND HAD ASBESTOS FIBERS IN IT…

  23. HomeEnergyNow February 20, 2013 at 1:25 pm #

    Many blown fiberglass manufacturers have ratings for walls that are R-15, in 3.5 inches. That is R-4.3/inch. You would think after 20 years you would know that…….

  24. Diying Mee June 9, 2013 at 5:38 pm #

    This is non-sense for cellulose. CELLULOSE DOES NOT REQUIRE IN INNER (WARM SITE) Vapor barrier, not even in cold climates. What you read on the internet is just comments made by people who have something to lose if too many people stop buying Roxel and Corning (rockwool and fiberglass) simple. They cause fear and confusing so people keep going right back to what they want, fiberglass and rockwool.

  25. GlueFactoryBJJ September 14, 2013 at 6:09 pm #

    Another point to consider is that if there is a fire, fiberglass melts very rapidly, basically providing almost no fire retardant benefits. OTOH, blown cellulose, almost counterintuitively, has significant fire retardant capabilities and can provide a notable increase in time before the structure collapses. Search for “The Big Burn” here on YouTube. It could mean the difference in your life and that of your house.

    Disclaimer: I don’t have any financial interest in either type of insulation.