Open-cell and closed-cell polyurethane foam that air-seals and insulates in one application — installed on roof decks, walls, and crawl spaces throughout Marathon.
Spray foam is the only insulation on this list that stops air movement and heat transfer at the same time. In Marathon, that matters more than the R-value on the label. A Monroe County attic can run 130°F in August while the air handler fights to keep the house at 76°F, and most of that battle is lost through gaps — around can lights, at the top plates, where the soffit meets the roof deck. Foam seals those as it expands, which is why homes here often feel different within a day of the install rather than after a full billing cycle.
The reason spray foam keeps coming up in Marathon is humidity, not temperature. Monroe County homes lose comfort to moisture as much as to heat, and a vented attic pulls damp outside air across everything in it — including the ductwork. Closed-cell foam applied to the underside of the roof deck brings that whole volume inside the building envelope, so the ducts are no longer running through a hot, wet space. Homeowners describe the result as the air feeling drier, which is exactly what has happened.
Marathon sits in Florida Climate Zone 1 — the hottest, most humid zone in the continental United States. Under the Florida Building Code, Energy Conservation (8th Edition), the ceiling minimum here is R-30 and framed walls are R-13. ENERGY STAR recommends R-30 for an uninsulated attic in this zone; we build to R-38 as the practical target.
| Item | Value | Where it applies |
|---|---|---|
| Open-cell foam | R-3.7 per inch | Roof decks, interior walls, sound control |
| Closed-cell foam | R-6.5 to R-7.0 per inch | Roof decks, crawl spaces, block walls, flood-prone areas |
| Air sealing | Effectively eliminates envelope air leakage at the application surface | Both types |
| Vapor behavior | Closed-cell is a Class II vapor retarder at 1.5" and above | Closed-cell only |
We inspect the attic, roof deck condition, duct location, and any existing insulation, and confirm the roof has enough service life left to justify foam.
Existing insulation is removed where required, penetrations are prepped, and the work area and HVAC returns are masked and protected.
Foam is sprayed in controlled lifts to the specified thickness, checked with a depth gauge as we go rather than by eye.
The space is ventilated per the manufacturer's re-occupancy schedule before anyone goes back in.
We measure thickness, photograph the finished surface, and hand over documentation for permits, insurance, or a future sale.
Spray foam in Marathon typically runs $3.00 to $7.00 per square foot depending on foam type and thickness. A full closed-cell roof deck encapsulation on a 2,000 sq ft Marathon home usually lands between $6,000 and $13,000; open-cell on the same deck is meaningfully less.
Not sure spray foam is the right call? These are the other scopes we run in Marathon — and the Marathon insulation overview covers the whole envelope.
Loose-fill fiberglass or cellulose blown to a consistent, verified depth across Marathon attic floors — the fastest way to bring an under-insulated attic up to code.
Blown-In Insulation in Marathon →Pre-cut fiberglass and mineral wool batts fitted between studs, joists and trusses in Marathon homes, additions, garages and light commercial framing.
Batt Insulation in Marathon →HEPA-filtered vacuum removal and disposal of wet, contaminated, storm-damaged or rodent-infested insulation from Marathon attics, walls and crawl spaces.
Insulation Removal in Marathon →Attic, wall, floor and air-sealing work for Marathon houses, condos and townhomes — the whole envelope handled by one contractor instead of four.
Residential Insulation in Marathon →Envelope, mechanical and fire-rated insulation for Marathon offices, retail, restaurants, hotels, medical buildings, warehouses and cold storage — including night and weekend work in occupied space.
Commercial Insulation in Marathon →Spray foam in Marathon typically runs $3.00 to $7.00 per square foot depending on foam type and thickness. A full closed-cell roof deck encapsulation on a 2,000 sq ft Marathon home usually lands between $6,000 and $13,000; open-cell on the same deck is meaningfully less. Standard Insulation gives free written itemized estimates throughout Marathon and Monroe County — call (561) 975-6204.
Marathon sits in Florida Climate Zone 1 — the hottest, most humid zone in the continental United States. The Florida Building Code, Energy Conservation (8th Edition) sets a R-30 minimum for ceilings in this zone, and R-38 is the practical target for comfort and utility savings. Many Marathon homes built before 2005 still measure R-11 to R-19, which is a large part of why their summer bills run high.
Cooling is roughly half of a typical Marathon electric bill. Bringing an under-insulated attic up to a properly air-sealed R-38 commonly cuts the cooling portion by 20 to 30 percent — more if your ductwork runs through the attic. On a $300 summer bill that is usually $30 to $45 a month back.
It depends on the building and the budget, and we will tell you honestly which applies. If your attic is at R-13 and you want the most improvement per dollar, blown-in to R-38 with proper air sealing is the answer. If your ducts are in the attic and you want humidity control, closed-cell spray foam on the roof deck is the answer. If your roof is more than twelve years old, do the roof first — we will say so.
Yes, and it is a large share of what we do in Monroe County. Wet insulation does not recover — it mats down, loses its R-value permanently and holds moisture against your framing. We remove it under containment, document the condition for your insurer, dry and treat the deck, and reinstall once the cause is repaired.
Florida Keys Electric Cooperative is the main electric utility across Monroe County and publishes current residential efficiency incentives on its own site — we link to it below. Standard Insulation does not administer utility programs, but we supply the itemized invoice and R-value documentation these applications ask for.
Insulation-only retrofits in Monroe County usually do not require a permit, but new construction, additions and commercial work do, and the requirement is set locally rather than statewide. We confirm with the Monroe County building department before we start, and we link to their site below so you can check for yourself.
These are the outside sources we work from. None of them are ours — check them yourself before you sign anything with any contractor.
Written, itemized, and no obligation. We answer the phone 24 hours a day.
Request your free estimate 📞 (561) 975-6204
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