If your roof is in good shape, your attic is properly vented, and you mainly want to cut summer energy bills without a big upfront investment, blown-in insulation is usually the more practical choice for Dallas-Fort Worth homes. If you're dealing with duct work in an unconditioned attic, chronic hot spots in upstairs rooms, or you're re-roofing anyway and want to convert to a sealed, conditioned attic assembly, closed-cell spray foam solves problems blown-in insulation can't touch. There isn't a universal right answer here - it depends on your roof deck, your ductwork, your budget, and how you plan to handle a future hail claim. We'll walk through both, then get specific about what matters in North Texas.
Blown-in insulation - typically loose-fill fiberglass or cellulose - is installed by machine, filling the attic floor between and over the joists to a target depth. It's the insulation most North Texas houses built from the 1970s through the 2000s already have, usually in need of a top-off or full replacement by the time a home hits 20-30 years old, since loose-fill settles and compresses over time and loses R-value.
The attic stays vented in this approach - soffit vents pull in outside air, it moves up through the attic space, and ridge or gable vents let it out. The insulation layer sits on the attic floor, not against the roof deck, so the attic itself stays roughly the same temperature as outside air, while the living space below stays separated by the insulated ceiling plane. This is the traditional building approach for this climate, and it works fine as long as the ventilation is actually functioning and the ductwork running through the attic is well-sealed and insulated on its own.
Closed-cell spray polyurethane foam is applied directly to the underside of the roof deck, sealing the attic off from outside air entirely rather than venting it. This converts the attic from a vented, unconditioned space into a semi-conditioned one that stays much closer to indoor temperature year-round. Because the foam also acts as an air barrier, it stops the hot, humid outside air infiltration that loose-fill insulation does nothing to block.
For a North Texas attic that regularly hits 130-150°F on a July afternoon, that's a meaningful shift - your HVAC ductwork and equipment, if they're located up there, suddenly sit in a space closer to 90-100°F instead of attic-peak temperatures, which reduces the heat gain those ducts pick up before conditioned air ever reaches a supply register. Spray foam also adds structural rigidity to the roof deck itself and reduces the amount of air movement that carries dust, pollen, and moisture into the attic.
Cost: Blown-in insulation is the cheaper option per square foot by a wide margin - it's a fast, single-day install with no roof work required. Closed-cell spray foam costs several times more per square foot because of material cost and labor-intensive spray application, and pricing depends heavily on attic accessibility and thickness required to hit code R-values.
Lifespan: Quality closed-cell spray foam holds its R-value for decades and doesn't settle or compress the way loose-fill does. Blown-in fiberglass and cellulose lose loft and effectiveness over time, especially cellulose in attics that have had even minor roof leaks, and most North Texas attics benefit from a top-off or refresh well before the 20-year mark.
Wind rating: Neither product carries a wind rating in the way roofing materials do, since insulation isn't an exterior, wind-exposed assembly. Where wind does matter indirectly is straight-line wind and derecho events common to North Texas, which can strip shingles or damage the roof deck - in that scenario, spray foam adhered to the underside of the decking can actually add some racking resistance to the deck itself, a side benefit rather than a rated performance spec.
Maintenance: Blown-in insulation needs almost no attention beyond checking depth every several years and confirming ventilation isn't blocked by stored items or animal nesting. Spray foam needs even less routine maintenance, but it comes with one maintenance complication worth knowing about before you commit: if a hailstorm damages your roof badly enough to require deck replacement, foam bonded directly to the underside of that decking makes tear-off dramatically more labor-intensive, since crews have to grind or scrape cured foam off the old decking or account for it in the new install. That's a real cost and time factor to weigh given how often North Texas roofs see hail-driven claims.
Appearance: This is entirely an attic-space consideration, not a curb-appeal one - neither product is visible from outside the home. Inside the attic, spray foam gives a cleaner, sealed look along the roofline, while blown-in insulation simply covers the attic floor and is the more familiar sight to most home inspectors and appraisers in this market.
For most existing North Texas homes with a functioning vented attic and a roof that isn't due for full replacement soon, we typically point homeowners toward blown-in insulation as the better value: it directly targets the biggest driver of high summer electric bills - undersized or settled attic insulation - at a fraction of the cost of converting the whole attic assembly. It's also the lower-risk choice if a hailstorm hits your roof next season and the deck needs work, since there's no foam bonded to the underside to deal with during repairs.
Spray foam earns its higher price tag in specific situations: homes with ductwork and HVAC equipment located in the attic (very common in DFW slab-on-grade construction), homes with chronically hot upstairs rooms despite adequate attic insulation depth, or homeowners who are already re-roofing and want to convert to a sealed attic as part of that project rather than as a standalone job. If your foundation has had movement - not unusual in the expansive clay soils across the Metroplex - and that's caused gaps or cracks in the ceiling plane and top plates, spray foam's air-sealing properties can also help close off some of the air leakage those movement cracks create, something loose-fill alone won't fix.
Alpine Exteriors evaluates the roof deck, existing ventilation, ductwork location, and your home's specific heat-gain problems before recommending either option - because the right call really does change house to house, and the wrong one either wastes money or creates a headache at your next hail claim.
It depends on the manufacturer and whether the foam is applied to new or existing decking. Some shingle manufacturers require specific ventilation or deck-preparation conditions for their warranty to remain valid, so this should be confirmed with your specific roofing material's documentation before converting an attic to unvented spray foam.
Not much on its own - a vented attic with loose-fill insulation still allows outside air, and the dust and pollen it carries, to move through the space. Spray foam's air-sealing does reduce this infiltration more effectively, which is worth considering if allergy symptoms are a factor in the decision.
Hail itself doesn't damage attic insulation, since it never reaches the insulation layer directly. The connection is indirect: if hail damage requires deck replacement down the road, spray foam bonded to that deck adds cost and labor to the repair, while blown-in insulation on the attic floor is unaffected by roof-level hail repairs.
Yes, this is a legitimate approach in homes with complex rooflines or attic sections used for storage versus mechanical equipment. It's more common to spray foam a smaller area around ductwork or a knee wall while leaving the main attic floor as blown-in, which can control costs while still solving a specific hot-spot problem.
Every North Texas attic is dealing with the same summer heat and the same hail-and-wind risk, but the right insulation approach still comes down to your specific roof, ductwork, and budget. Alpine Exteriors serves homeowners across Dallas, Fort Worth, Plano, Frisco, Arlington, Irving, McKinney, and Denton, and we're glad to walk your attic with you, look at what's already up there, and lay out real cost ranges for both options before you spend a dollar. Contact us to schedule an attic evaluation.