Blown-In Insulation in Boca Raton: The Complete 2026 Guide

Why blown-in is the Boca attic default

Blown-in insulation — cellulose or loose-fill fiberglass — is the most common attic retrofit in Boca Raton for one reason: it's the lowest cost per R-value of any material that fills an attic floor completely. No gaps, no compression, no batts to cut around recessed lights and ductwork.

For a dry attic that just needs more R-value, blown-in is the right answer. It's not the right answer for every attic — but when it is, nothing beats the value.

Cellulose vs. loose-fill fiberglass

| Material | R-value per inch | Cost per sq ft | Best for | |---|---|---|---| | Cellulose | R-3.8 | $1.00–$2.00 | Most Boca attics, fire-resistant, dense | | Loose-fill fiberglass | R-2.2–R-2.7 | $0.80–$1.50 | Very dry attics, budget top-up |

Cellulose is denser, settles less, and is treated with borate fire retardant — which also deters pests. In Boca's humidity, we install cellulose more often than loose-fill fiberglass because it holds its R-value better when humidity spikes.

The step most contractors skip: air sealing

Blown-in insulation slows conductive heat — but it does not stop air movement. If your attic has bypasses (can lights, plumbing penetrations, attic hatch, duct chases), hot humid attic air flows through the insulation into your living space. Blowing in 16 inches of cellulose over unsealed bypasses gives you a thick blanket with holes in it.

Before any blown-in install, we air seal the attic floor: caulk and foam every penetration, seal the attic hatch, and box around recessed lights. This step is the difference between a blown-in job that drops your FPL bill 15–20% and one that does nothing.

What it costs in the Boca corridor

Blown-in attic insulation across Boca Raton, Delray Beach, and Boynton Beach runs $1.50–$4.00 per square foot installed, including air sealing. A typical 2,000 sq ft attic is $3,000–$6,000 to bring from R-19 up to R-49 (Florida code for new construction).

That's roughly half the cost of a closed-cell spray foam retrofit — which is why blown-in is the default when the attic is dry and the budget matters.

When blown-in is the wrong choice

Blown-in is not the right call if:

• Your attic has had any water event. Wet cellulose compacts and molds. Remove the old material first.
• You're conditioning the attic. If you're moving the thermal boundary to the roof deck (conditioned attic), you want spray foam on the underside of the roof, not blown-in on the floor.
• Your problem is radiant heat, not conductive. A 145°F attic radiates heat downward through any insulation. A radiant barrier under the roof deck stops radiant heat at the source; blown-in only slows what gets through.

The right next step

If your attic is dry and you want the most cost-effective R-value boost in Boca, blown-in cellulose with air sealing is it. If you're not sure whether your attic is a blown-in candidate or needs foam, a free FLIR inspection tells you in 30 minutes.

Call (561) 654-7698 for an instant quote by ZIP. We serve Boca Raton, Delray Beach, Boynton Beach, West Palm Beach, and Parkland — 5.0 stars on Google.