The Home Insulators

Basement Insulation in Ulster County, NY

In most Ulster County houses the basement is already half inside the house, whether anyone planned it that way or not. The boiler is down there, the oil tank beside it, the water heater and the duct or pipe runs overhead, and 44.9% of occupied homes in the county burn oil or kerosene with another 13.2% on propane. Once the heating plant lives in a space, that space belongs inside the insulated shell, which means the work goes on the foundation walls and the rim joist rather than the ceiling.

The foundations themselves decide the method. A quarter of the county’s 86,178 housing units, 25.3%, went up before 1940 on stone or rubble walls that no sheet of board will ever lie flat against, and the postwar decades added poured and block walls that will. Both get insulated, just not with the same material.

Where basement insulation pays in Ulster County houses

The rim joist, in every one of them. This is the band of framing sitting on the sill at the top of the foundation, and it leaks at three lines at once: sill to masonry, rim to sill, and rim to subfloor. Warm air lost at the attic is replaced by cold air drawn in here. Where a whole-basement job is more than the budget allows, sealing and insulating the rim alone still returns comfort and fuel, which is why it is the first thing we price in a house anywhere from Saugerties to Plattekill.

Stone and rubble cellars under pre-war houses. The City of Kingston is 54.1% pre-1940, Rosendale 31.4%, Wawarsing 28.9% and Marbletown 28.6%. Cellar walls in those houses are irregular by nature, and rigid board bridging the high spots leaves hollows behind it where house air reaches cold masonry. Closed cell foam sprayed onto the wall follows every bulge and seals the sill in the same pass, which is why it is the standard answer under an old Ulster County house.

Walk-out and daylight basements on hillside lots. The 1960s and 70s are 35.4% of Hurley, 29.5% of Plattekill and 26.6% of the Town of Ulster, an era that liked the raised ranch and the split, both of which put finished rooms half below grade. Those walls are poured or block and flat enough for board, and the rules of thumb change with the grade: the top of a foundation wall is by far the most important part thermally, and it is also the part exposed to outdoor air on the downhill side.

Cellars shared by two households. Two-unit buildings are 19.1% of the City of Kingston and buildings of three or four another 11.6%, with Lloyd at 8.6% and 5.7%. One stair, one boiler, one cellar: the air path runs through the whole building, so a two-family is priced as one envelope rather than as two apartments, and the owner decides the work.

Basements that end in a crawl space. Plenty of houses here have a full cellar under part of the plan and a crawl under an addition or a kitchen wing, with a doorway or a low block wall between them. They share air and they get one plan; the crawl half is covered in our crawl space encapsulation page.

How we do basement insulation in Ulster County

Water comes before insulation, without exception. Standing water, wet cracks, white efflorescence on the block, condensation on pipes or a damp smell means the source gets dealt with first, and insulation over a wet wall makes matters worse rather than better. Gutters, grading, crack repair, interior drains and sump work belong to the waterproofing and drainage trades. Radon is tested before the space is tightened and again afterwards, and mitigation is designed by a radon contractor. Where a basement runs above 60 percent relative humidity, a drained dehumidifier is part of the plan.

Then the rim joist. Closed cell foam in the joist ends joins foundation, sill, rim and subfloor into one air barrier and keeps house air off cold wood; the code allows that foam to stay uncovered up to 3 1/4 inches, roughly R-22 to R-23, when its density and flame-spread ratings fall inside the limits. Where board is used instead, each piece is cut snug to the bay and sealed on all four edges, and unfaced or with the film peeled so the rim can still dry. Batts are the weakest choice, because house air passes through fiber and reaches the cold band behind it.

Then the walls, and only moisture-tolerant material touches masonry. Closed cell foam at R-6.9 to R-7.1 per inch goes straight onto stone, block or poured concrete and just over two inches reaches R-15. Unfaced rigid board suits a flat wall, glued in full contact with every seam and edge sealed so no air can get behind it, and it stops at the thickness that still lets the wall dry inward. What never goes in is a stud wall packed with fiberglass against bare concrete and wrapped in plastic: the batts hold the moisture, the plastic stops it drying, and mold follows. Where a finished room is wanted, the framing stands off the concrete, the foam goes on continuously behind it, unfaced batts fill the studs if more R-value is needed, and the drywall is held off the slab.

Old material comes out first where it has failed. Wet, settled or rodent-fouled insulation and sagging blanket batts are bagged and taken out under containment, with a HEPA insulation vacuum; mold on joists, framing or the foundation is remediation work and goes to that trade before we start. Old pipe wrap and pebble-like vermiculite stay untouched until a licensed professional has tested them. Foam on a basement wall needs a thermal barrier over it — half-inch gypsum or an equivalent — whether the basement is finished or not, unless the product carries approval for exposed use.

What basement insulation costs in Ulster County

Most of our projects run between $3,500 and $12,500. A rim-joist-only job is the low end of that, and a full cellar in a pre-war house the high end. The figure follows wall area and height, whether the walls take board or have to be foamed, the number of bays and penetrations at the rim, how much failed insulation has to come out, the headroom and the access — a Kingston cellar reached by a narrow stair takes longer than a walk-out under a raised ranch — and whether a thermal barrier has to be installed over the foam. Waterproofing, drainage, radon systems, electrical and drywall are quoted by the trades that perform them. See our insulation cost guide.

Rebates for basement insulation in Ulster County

Central Hudson is the electric utility in every town here except Shawangunk, which it shares with NYSEG; the name on the bill tells you which one a given street has. Gas service exists in the city, the Village of Saugerties and parts of Esopus, Lloyd and the Town of Ulster, and hardly at all elsewhere, so most basement work in the county is quoted for a house heated by delivered fuel and metered by one of those two electric companies. Both collect the System Benefits Charge, which is what opens NYSERDA’s door.

The rim joist has its own line in the state program. Comfort Home pays $2,500 for the attic-and-rim-joist package and $3,000 when wall and floor work is added, through a NYSERDA-approved Comfort Home contractor, for market-rate homes of one to four units. It sets the rim joist at R-14 and requires closed cell foam if two-part spray foam is the material used there, and for the larger package it counts basement foundation walls insulated to at least 18 inches below grade. Comfort Home runs through 2026 and gives way to the utilities’ new weatherization programs around January 2027.

Income-eligible households use EmPower+, where the work can be no cost up to $14,000, or half the cost up to $7,000 at the moderate-income tier, through an EmPower+ contractor; the 2026 Ulster County no-cost limits are $50,325 for a single person and $80,160 for a household of four, and renters as well as owners may apply. Federal HEAR money inside it adds up to $1,600 toward air sealing, insulation and ventilation. Each program pays only through the contractors taking part in it, which is worth asking about before you sign with any company, us included. The federal 25C credit ended for work placed in service after 31 December 2025, and New York has no state tax credit for insulation. Our New York rebate guide keeps the current detail.

Code and climate in Ulster County

New York puts Ulster in Climate Zone 6, but the basement numbers do not change with the zone here: the 2025 Energy Conservation Construction Code of New York State, effective 31 December 2025, asks for R-15 continuous, R-19 in a cavity, or R-13 cavity plus R-5 continuous on a basement wall in every one of the state’s zones. In practice that is a little over two inches of closed cell foam, four inches of unfaced expanded polystyrene, or an inch of extruded board behind a 2×4 wall holding R-13 batts.

Where a basement is heated, the insulation runs from the top of the wall down to the basement floor, or to ten feet below grade if that comes first. A slab only falls under the code’s floor rule when it sits within 24 inches of grade, so insulating the floor of a deep Ulster County cellar is a comfort and moisture decision rather than a code one — and a ground temperature near 55 degrees all year is why a slab sweats in August. A Class I vapor retarder is not allowed to serve as the air barrier on a below-grade wall, and the residential code does not ask for a vapor retarder on a basement wall at all, which is the opposite of what the old plastic-wrapped stud walls assumed.

Towns we serve in Ulster County

We insulate basements and cellars across the county, city blocks and hill farms alike. Sixteen places have pages of their own.

Common questions about basement insulation in Ulster County

Why start with the rim joist?

It is the cheapest square footage of air sealing in the house. The band of framing on top of the foundation leaks where the sill meets masonry, where the rim meets the sill and where it meets the subfloor, and on a cold night that is where the replacement air for everything escaping upstairs comes in. Closed cell foam in the joist ends ties all of it into one barrier and keeps house air off cold wood. On a tight budget, rim joists alone are worth doing.

Rigid foam or spray foam for an Ulster County basement wall?

The wall decides. Poured or block walls in postwar houses are flat enough for unfaced rigid board, glued in full contact with every seam and edge sealed so no air gets behind it. Stone and rubble cellars under pre-1940 houses are not: board bridges the high points and leaves voids against cold masonry, so closed cell foam is sprayed directly on, filling the irregularities and sealing the sill in one pass. Just over two inches of closed cell reaches the R-15 the code asks for.

Should I insulate the cellar ceiling instead of the walls?

Only when the cellar is dry, unfinished, staying unheated, and holds no furnace, boiler, water heater, ducts or unprotected pipes. In this county that combination is rare, because so many cellars hold an oil boiler and a tank. Where the equipment is down there, insulating the ceiling leaves it in an unheated space and leaves the pipes at risk, so the walls and rim are the right target. Ceiling insulation between a cellar and the rooms above mostly buys quiet.

Do you waterproof a basement as part of the job?

No. Waterproofing, interior drains, sump pumps and crack repair are a separate trade, priced by the contractors who do that work, and mold remediation is another. Our part starts once the water is stopped: air sealing, the rim joist, foam or board on the walls, and removal of whatever failed insulation is down there. If the source of water cannot be removed, the honest answer is not to insulate over it, and we will tell you that on the walk-through rather than after.

Free energy audit in Ulster County

We begin at the bottom of the stairs: the wall material and how even it is, the damp line on the block, the rim and sill, the pipes and ducts, the boiler or furnace and its flue, the tank, and whatever insulation is already down there and what state it is in. Outside we look at the grade and the gutters, because that is usually where a wet cellar begins. The scope and price come in writing, along with a straight list of what another trade has to handle first.

Call 914-825-6824 or use the contact form, 8am–8pm, seven days. The Home Insulators is family-owned, works out of New Rochelle, NY, and sends a 100-plus-person in-house crew that never subcontracts.

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