A1-1B – Install All Boric Cellulose

The proper step before installing blown cellulose, is A1-1A Air Seal the attic floor. Once we have stopped the conditioned air from escaping, we can then blow in a thick blanket of All Boric Cellulose.

Why you should AVOID having fiberglass installed in your attic?

How much blown insulation do I need in my attic?

The Energy Star recommended level of attic insulation is R-60, which often allows us to bury the HVAC ductwork and deliver air at the right temperature. While on the other side of the spectrum you have the Code Required minimum of blown insulation which is R-49 (it was R-38 until Oct 2021).

Stellrr recommends R-60 which is the Energy Star recommended installation level. R-49 is the code minimum required installation level, and may be a consideration if budget restraints require cutting back on the scope of work.

Why do you ONLY want the cellulose that Stellrr installs? Wildlife control side effect.

What dirty tricks do I need to look out for when comparing quotes from contractors?

The Inches Gimmick – Yesterday I gave a proposal to a nice young lady Sharon who had just finished having the electrical re-wired on her house… the second time this year! The first contractor did it wrong, and was the cheaper estimate.

Anyway, she had a proposal from a competitor whose work we often fix. The competitor’s proposal was cheaper. The competitor’s quote said 17 inches of insulation (fiberglass). And she wanted to know how many inches my R-38 (budget option) proposal included.

I told Sharon that there were several differences. The competitor quote was to use her existing contaminated insulation (7 inches), and to add 10 inches to it (10” x R-2.2 per inch = R-22 added). A total fiberglass R-value of about R-38. The competitor used the word “air seal” in his proposal but used zero details on what it entailed.

Whereas my proposal for R-38 cellulose (budget option) was to A10-1 Remove Existing, A1-1A Air Seal and then A1-1B blow in R-38 of cellulose.

See the difference? The competitor installed R-22, we installed R-38. His R-value is the same because he used what was there, but we installed twice the insulation.

Sharon wanted to know…

How many inches will I have when Stellrr is done?

I explained that our All Boric Cellulose is R3.7 per inch compared to the competitors R2.2 per inch. So we install 10” to achieve the same thing they do with 17”. While it sounds like they are putting a lot more in, it just isn’t true.

What’s more problematic is this, half of her house attic roof is so LOW, that the competitor couldn’t even get 17 inches installed. So in this case she really needed the more dense, higher R-value insulation that we install.

So as you can see, we were comparing apples to oranges.

How well does Stellrr’s cellulose resist fire?

Fire Testing Insulation Materials.

Stellrr recommends TruSoft cellulose because it is highly fire resistant compared to spray foam, and fiberglass. In case of fire, your family has more time to get out safely, the flame will spread less and damage less with cellulose. Watch this burn test video on different insulation materials…


How does cellulose compare to fiberglass in HEAT resistance? There is a huge difference.

What does the attic look like after installation?

How messy is the installation?

Regardless of which insulation material you have blown or sprayed, it is very messy in the space where the work is done. With cellulose there is no vapor, but there is a dust cloud. The good news about cellulose is that the duct cloud is not harmful. It is ground up paper products with a boric (a cleaner). Compare it to fiberglass which is glass shards floating in the air. Fiberglass is itchy, it takes days to get out of your throat and off your skin.

Outside of the space where the installation happens, it is pretty clean. But we always recommend that you have someone come in and deep clean the house after installation, just in case.

Can we stay in the house during installation?

You need to stay out of the space where the work is happening (attic), but you can stay in the house.

What other line items solutions may be needed in my attic?

spray foam insulation austin

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