How To Compare Blown-In Fiberglass Insulation

Woman shaking hands with salesman sitting beside husband on couch at homeAs a roofing contractor or remodeler, when you submit a re-roofing proposal for a homeowner, it's the ideal time to suggest upgrading the attic insulation to help them save on utility costs in the summer and winter. We explored the opportunity in a previous blog regarding the advantages of suggesting attic insulation when bidding roof jobs. If you're going to incorporate blown-in attic insulation to your roofing proposals, that's great! Next, you'll need to decide what brand of insulation to use and where to buy it from...

Blown-in insulation is available at many big box stores, as well as roofing distributors. And while it's common for big boxes to prominently promote a low price per bag on fiberglass, it's important to look a little deeper - because not all fiberglass insulation is created equal. Let's take a look at an example based on a quick price shop:

Seller Product Advertised Bag Price
Big Box "M" Guardian Fiberglass Blown-In Insulation $34.57/bag
Big Box "L" Owens Corning AttiCat Blown-In Insulation $34.57/bag
Distributor "W" Owens Corning ProCat Blown-In Insulation $36.50/bag


By a strict price comparison per bag, it looks like Big Box M's Guardian Fiberglass Blown-In Insulation and Big Box L's Owens Corning AttiCat are tied for the best value, while Distributor W's Owens Corning ProCat is 6% more expensive.


Coverage Matters: Time & Materials

Every F/G blown-in insulation product has a different coverage rate, or the amount of insulation required to insulate a given area of attic space at a specific R-value. This is usually shown in a table on the bag itself, as well as the manufacturers' website. The value is typically expressed for key R-Values as both a number of bags/sqft, and as a net coverage/bag. Using the net coverage/bag, we can arrive at a real cost/sqft. Let's add that to our table, using R-30 as a common insulating value for a typical blown-in insulation job:

Seller Product Advertised Bag Price Coverage: sqft/bag @ R-30 $/sqft
Big Box "M" Guardian Fiberglass Blown-In Insulation $34.57/bag 65.3 sqft (data sheet) $.53
Big Box "L" Owens Corning AttiCat Blown-In Insulation $34.57/bag 68.5 sqft (data sheet) $.50
Distributor "W" Owens Corning ProCat Blown-In Insulation $36.50/bag 80.6 sqft (data sheet) $.45


Owens Corning ProCat Blowing MachineWow - all of a sudden, the product with the highest bag price, Owens Corning ProCat, becomes the best value due to its superior coverage rate. Moreover, with an 80.6 sqft coverage per bag at R-30, it will take just 13 bags ($474.50) to insulate a 1,000 sqft attic - versus 15 bags of Owens Corning AttiCat ($518.55) or 16 bags of the Guardian product ($553.12).  That's a swing of almost $80 per thousand sqft! Less bags translates to less labor time for your crew during installation - saving you more time and money.

Don't Forget Level of Service

An additional factor that can help you determine where to buy blown-in insulation is the level of service provided by the distributor. Many, but not all, distributors and home centers will rent the blowing equipment to you for free as a convenience with a 10+ bag purchase. On the other hand, some big boxes will charge $25 for a four-hour rental, and additional fees for more time - not ideal for professional contractors!

Take the Time to Find the Best Value

Blown-in attic insulation can be a great add-on for roofing sales.  When figuring blown-in fiberglass insulation into your roofing quotes, select the product with the highest coverage rate and best value, and the distributor that provides the best equipment rental program. You'll maximize your profitability and increase your labor efficiency at the same time!

Tags Insulation Blown In Insulation

About Dave Karras

Dave Karras

Dave Karras is the Marketing Manager at Wimsatt Building Materials.

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