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Discussion Starter · #1 ·
What is the advantage of blown in fiberglass insulation over batt insulation?
I know blown in is faster and easier to install. Lets say you blow in 24" inches of blown; how is would that be better than laying 24" inches of batt?
 

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What is the advantage of blown in fiberglass insulation over batt insulation?
I know blown in is faster and easier to install. Lets say you blow in 24" inches of blown; how is would that be better than laying 24" inches of batt?
Blown will sag over time with humidity,etc, and it will reduce the R-Value, not to mention using in the attic, good chances you will block soffit vents if they exist.
 

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Blown will sag over time with humidity,etc, and it will reduce the R-Value, not to mention using in the attic, good chances you will block soffit vents if they exist.
There are guys here in NJ and im sure elsewhere who are advertising themselves as Energy efficient contractors. They do an inspection and basically price out for the blown in insulation roughly 2-3k per floor of say a 1800 sq ft house..

Now im not saying what they are doing is wrong or shady but they are promoting a huge savings in energy.

IM Wondering if the benefit is worth the price..Your basically talking 4-6k for a two story house..any thoughts..
 

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I'm assuming new construction. Blown walls do a better job of keeping air infiltration down and don't have issues with fitting correctly in odd spaces. Around here, the better companies will use batts in the attic, and then blow over the top of them.

I think a $6K blown fiberglass job in NJ is going to have a pretty long payback period. Air infiltration is better addressed by air sealing during the build - not making a leaky shell and trying to slow down the leakage.
 

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Discussion Starter · #5 ·
Blown will sag over time with humidity,etc, and it will reduce the R-Value, not to mention using in the attic, good chances you will block soffit vents if they exist.

Greg,
Any guy with half a brain would know to add soffit baffles before blowing the insulation.
I think i prefer blown in fiberglass( atticat) in the attic and maybe cellulose in walls.
To stop air flow, the sky is the limit with blown in fiberglass, you can go up 36" in an attic whereas in a wall, its only an R13- R15 tops. Cellulose might have an airflow advantage in a smaller opening such as a wall cavity. For an attic , definitely the ownens corning atticat.
 

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Discussion Starter · #8 ·
why not cellulose?
Well, i know its been tested and its treated with certain chemicals, i just have an issue with the fact that its made of recycled newspaper which is a convern ro me if its exposed ro moisture/ water. It does also settle over 20% sometimes and that can effect the Rvalue. That said, it is good material,i just have a few worries.
Blown in fiberglass ( attiCat) does NOT have the binders in it that make you itchy and also no faLmaldahyde( spelling). It doesnt absorb moisture, doesnt settle, and no mold can grow on it. Its also a cleaner installation, no dust.
Thats just my opinion, there are guys that love cellulose.
 

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Batt insulation is only effective if you have a complete air barrier. Any air infiltration in a batt and the batt turns into an air filter, and the R value is reduced tremendously. More over of you don't install the batt to completely touch all framing and drywall the R value is immediacy reduced by an R5. Fiberglass blown in is no better than a batt if you don't have an air barrier. Cellulose will slow down the air movement, but won't completely stop it like foam. Cellulose applied correctly should allow for settling (which any blown product does). Cellulose is a much better product.
 

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What is the advantage of blown in fiberglass insulation over batt insulation?
I know blown in is faster and easier to install. Lets say you blow in 24" inches of blown; how is would that be better than laying 24" inches of batt?
It gets into all the crooks and nannys, fast n cheap, what's not to like?
 

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I believe, may be wrong, that cellulose reaches its R-value once it's settled. On initial application it is fluffy and full of air. Once it settles, it is denser. Our installer blows more than needed to allow for settling. We use cellulose in almost all of our attics.
 

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Cchrc.org has both cellulose and fiberglass in their roof installed to r60 per manufacturer, full of sensors. The cellulose is performing much better.

Fiberglass is much more pleasant to install, but cellulose air seals better. For retrofit, the air sealing can be a big benefit. In walls the fiberglass air seals much better than it does in ceilings because it is much denser.

Regarding payback periods, in colder climates they can range from quick to almost never, but the added comfort can be worth something too.
 

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I believe, may be wrong, that cellulose reaches its R-value once it's settled. On initial application it is fluffy and full of air. Once it settles, it is denser. Our installer blows more than needed to allow for settling. We use cellulose in almost all of our attics.
Yes, it has an installed thickness and a settled thickness specified.
 

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New here. Glad to see all the insulation heads out there. For my two cents, the question is not which is better but who is putting it in. Either can be effective and both have pluses and minuses. Either one installed properly will do the job. Emphasis on properly. I prefer batt because blown in tends to lend itself to contractors who are blow and go and don't go the due diligence to install it right.

Casey
Diamond J Insulation
www.diamondjinsulation.com
 
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