Spray Foam Insulation in Staten Island, NY

Spray foam insulation on Staten Island has two jobs that most places only have one of. It has to keep a house comfortable through humid summers and cold, damp winters, and on much of the island it has to cope with water below the first floor. We air seal and insulate attics, walls, basements, crawl spaces and rim joists across the borough, using closed-cell or open-cell spray foam where it earns its cost and blown-in cellulose or fiberglass where that does the job for less. Every price is written after an on-site visit.

The climate we insulate for

New York City sits in a humid subtropical climate, according to Wikipedia's Climate of New York City article. The 1991-2020 normals for Central Park show a January daily mean of 33.7F, a July daily mean of 77.5F, about 29.8 inches of snow a year and roughly 49.5 inches of precipitation. July and August dew points average close to 62F. In practical terms, that means an attic that bakes all summer, a top floor the air conditioner struggles to cool, and a lot of moisture in the air looking for a cold surface to condense on. Staten Island's own official climate records are kept at Prohibition Park in Westerleigh, but the pattern is the same: warm, sticky summers and winters cold enough to make drafty houses expensive to heat.

What the energy code asks for

The 2025 New York City Energy Conservation Code says Climate Zone 4A applies to all projects in the city. Its residential insulation table for that zone lists R-49 for ceilings; R-30 for wood-frame walls, or R-20 in the cavity plus R-5 continuous, or R-13 plus R-10 continuous; R-30 for floors; and R-15 continuous or R-19 in the cavity for basement and crawl space walls. The same code caps air leakage at 3.0 air changes per hour at 50 pascals. Those numbers apply to new work and renovations that trigger the code, but they are also a fair yardstick for an existing house. Most Staten Island homes built before the 1990s fall short somewhere, usually in the attic and at the rim joist.

Water, flooding and the lower level

Hurricane Sandy hit the island on October 29, 2012. Wikipedia's account of the storm in New York reports at least 21 deaths on Staten Island, a storm surge of 9.56 feet above normal tide near the Kill Van Kull, and the state's highest observed water line, 7.9 feet above ground, on a doorframe in Oakwood. Whole blocks were washed away in Midland Beach, New Dorp and Oakwood Beach. Many houses near the shore have been rebuilt or raised since then, and many lower levels have been gutted and redone.

That history shapes how we insulate below the first floor. FEMA's Technical Bulletin 2 says only Class 4 and Class 5 flood damage-resistant materials are acceptable below the base flood elevation in a special flood hazard area, and it defines those as materials that can take at least 72 hours of contact with floodwater without more than cosmetic repair. If your house is in a mapped flood zone, we check what the rules require for the space before recommending a material, and we talk through closed-cell foam, rigid board and other options with you.

Closed cell vs open cell

Open-cell foam is soft and light. HomeGuide lists it at R-3.5 to R-3.7 per inch. It expands a lot, fills irregular cavities and seals air well, and it dampens sound, which helps in houses near the expressway or a busy road. Water vapor can pass through it, so it needs a moisture plan. Closed-cell foam is dense and rigid at R-5 to R-7 per inch. At normal thickness it slows vapor, absorbs very little water and stiffens the surface it is sprayed on.

On Staten Island we usually reach for closed-cell on rim joists, basement and crawl space walls, the underside of roof decks in cathedral ceilings, and anywhere the space floods or stays damp. Open-cell fits interior walls, above-grade wall cavities and many attic rooflines. On a wide open attic floor, sealing the gaps and blowing in cellulose to depth is often the better value, and we will say so.

Questions to ask insulation contractors

When you call spray foam insulation contractors or insulation companies on Staten Island, a few questions show who has thought about your house. Ask what they will seal before they insulate. Ask which foam they plan for each area and why, and what thickness and R-value the quote shows. Ask how they ventilate during spraying and how long you need to stay out (HomeGuide advises allowing at least 24 hours). Ask what they do with old insulation that is wet or moldy, and how they handle a basement that has flooded before. A quote that lists each area with its own material, thickness and price is easy to compare. Ours does.

Spray foam insulation cost

HomeGuide's 2026 guide puts installed spray foam at $1.50 to $5.00 per square foot: $1.50 to $3.50 for open-cell and $3.00 to $5.00 for closed-cell. It lists rim joists at $2,000 to $2,500, an attic at $3,000 to $8,000 and a whole house at $8,000 to $20,000, and notes that many installers charge a minimum of $1,000 to $2,000 or more. Fixr's figures for existing homes run higher, $3.15 to $7.50 per square foot for existing walls. These are national numbers. On Staten Island, tight attic access in older houses, debris removal after flooding and the need to protect finished rooms can move the total. The written estimate we give you after the visit is what you pay.

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We work in every part of the island. North Shore neighborhoods like St. George, Stapleton, Port Richmond and West Brighton hold many of the borough's 19th-century frame houses, with balloon framing, plaster walls and little or no wall insulation. The Mid-Island, from Westerleigh and Willowbrook to New Springville, Todt Hill and Dongan Hills, filled in with single-family homes after the Verrazzano-Narrows Bridge opened in 1964. The East and South Shore, from South Beach, Midland Beach and New Dorp to Great Kills, Eltingville, Annadale, Prince's Bay, Rossville, Charleston and Tottenville, mixes old beach bungalows, postwar capes, 1970s to 1990s development and newer townhouses, and much of it sits low enough that flooding is part of the conversation. Pick your neighborhood below to see what we look for there.