Phoenix Insulation FAQ

Most Phoenix attics do well between R-38 and R-49. If your attic has very little insulation left, R-49 is our usual recommendation. The right number depends on what is up there now, your ducts and your goals, so we check it during the free attic inspection. Blown-in fiberglass runs $1.35 per sq ft for R-38 and $1.65 for R-49.

We will not promise a dollar figure, because every house is different. What we can tell you is that Phoenix attics can reach 150 F in summer, and a thin or leaky attic makes your AC work harder all day. Adding insulation and sealing air leaks takes load off the system. We also help with APS and SRP rebates through our attic package.

Blown-in fiberglass is our most common attic fix: it fills around obstructions and goes down fast. Spray foam insulates and seals air leaks in one pass, which suits rooflines and tricky cavities. Batt insulation comes in pre-cut pieces, works in open walls, and is harder to fit well in an existing attic. We use Knauf Jet Stream Ultra blown fiberglass.

Sometimes you can add on top, but removal is the better call when the old insulation is dirty, damaged, matted down or has rodent droppings in it. Our order of work is removal first, then air sealing, then new insulation. Sealing comes after removal so we can reach the gaps. The inspection shows which route fits your attic. See our insulation removal service.

Properly installed blown-in fiberglass and spray foam both last for decades in an Arizona attic. What shortens their life is not the heat. It is pests getting in, roof leaks that soak the material, and other trades disturbing it. A look at the attic after roof work or pest treatment is smart, and our attic inspections come with photos so you can see the condition.

Open-cell foam gives about R-3.6 to 3.9 per inch, costs less and is a good fit for large areas and sound control. Closed-cell foam gives about R-6 to 7 per inch, blocks moisture and adds stiffness, so it suits tight spaces. Both seal air leaks well. We price both by custom quote. Learn more about spray foam insulation.

Yes. The most common use is on the underside of the roof deck, which puts the attic and any ducts inside the conditioned envelope instead of a 150 F oven. On a flat attic floor, blown-in fiberglass is usually the better value. Spray foam is a custom quote because every roofline is different, and we will walk you through the options on our spray foam page.

Spray foam is considered safe when trained installers apply it correctly and it cures fully. The work area has to stay clear while it cures, and we explain the timing for your home before we start. Our own crews do the work, never subcontractors. Poor installation is the real risk, so ask any contractor who will be on your roof. Details are on our spray foam insulation page.