Before another Northern Michigan winter, the insulation options can feel overwhelming. Fiberglass batts, blown-in fiberglass, blown-in cellulose, and spray foam all promise lower bills. The trouble is that they work in different ways.
Story Basements is here to cover the two most common attic insulation options for homeowners. The best type of insulation for an attic depends on your home’s construction, existing insulation, ventilation, and needs.
Your Two Main Options: Blown-In vs. Spray Foam Insulation
Blown-in insulation is loose-fill fiberglass or cellulose that an installer blows across your attic floor through a hose. It traps air in countless small pockets, and that trapped air slows the heat moving between your rooms and the attic above. Blown-in installation settles easily around joists, wiring, and awkward corners, and it costs less on a large attic.
Closed-cell spray foam is a liquid polyurethane that expands on contact and cures dense and rigid. It does two jobs at once. It resists heat flow, and because the cured foam is air-impermeable, foam application also seals the gaps that let heated air escape.
That is the real difference in blown-in insulation vs. spray foam for the attic. Blown-in insulation adds thermal resistance, but it does not air-seal on its own. That matters most when your attic is finished or conditioned, or when it houses HVAC ducts.
R-Value and Air Sealing Matter
The effectiveness of attic insulation depends on two things: its R-value and how well the attic is air sealed. R-value measures resistance to heat flow, while air sealing prevents warm indoor air from escaping through gaps and cracks.
Air leaks are common around attic hatches, recessed lights, plumbing penetrations, and other openings. When warm air escapes through these gaps, cold air is pulled into the living space below, forcing your heating system to work harder. That’s why sealing air leaks should happen before adding insulation.
Blown-in insulation can provide the high R-values (resistance to heat flow) needed for northern Michigan attics, but it does not stop air movement on its own. Closed-cell spray foam, by contrast, combines insulation and air sealing in a single application while achieving a high R-value with less thickness.
At Story Basements, our insulation services address both insulation performance and air sealing. The same approach guides our basement insulation and crawlspace insulation solutions.
Your Attic’s Condition Shapes the Right Choice
If your attic is vented, accessible, and the existing insulation is still sound, blown-in insulation offers better value, though cellulose can absorb moisture and lose R-value in a damp attic. Closed-cell foam earns its price where blown-in cannot go. In a conditioned attic, it goes straight onto the roof sheathing with no ventilation gap, and it resists water while acting as a vapor retarder.
You do not always have to pick one. Some attics get a layer of spray foam to seal penetrations and gaps around ducts and plumbing. Then, insulation contractors use blown-in insulation over the top to add depth. Our completed projects show both materials at work in homes near Cadillac and for Buckley homeowners facing the same winters.
Get the Right Attic Insulation
Your construction, ventilation, moisture, existing insulation, and budget all shape the answer, and a poor fit can create moisture problems rather than savings. That is why our team assesses each attic first. Contact us at Story Basements today to book your attic assessment across Northern Michigan