A crawl space is the one part of a house where the ground is inside the building. Burlington County has a great many, because the county runs from the Delaware River out to the Pine Barrens and the shallow foundation follows the sand. Crawl space encapsulation closes that space into the house: a sealed liner over the earth, the vents shut, the rim and walls insulated, and one method running year-round to keep the air dry. Plastic thrown over the dirt of a still-vented crawl is not the same job, and the code does not treat it as one.
The stock explains the demand. Of the 185,617 housing units here, 64.4% are detached and 55.7% were framed before 1980, the median one in 1977. A vented crawl with batts stapled between the floor joists was simply how those houses were built. The crawl space belt also sits where heating fuel costs the most: countywide 70.0% of occupied homes burn utility gas, but Pemberton Township runs 17.7% on oil and 23.4% on electricity, and Medford is 7.0% oil.
Where crawl space encapsulation pays in Burlington County houses
The Pinelands lake settlements. Medford and Pemberton Township both sit inside the Pinelands National Reserve, and Medford’s place names are water: Taunton Lake, Birchwood Lakes, Oak Knoll. Medford is 80.0% detached with 35.9% of its houses built in the 1960s and 70s; Pemberton Township is 72.8% detached, 47.6% from those two decades, 69.0% of it pre-1980. Out there houses were set on low block stem walls rather than dug in, and what we find under the floor is batts hanging out of the joists, rusted hangers and bare sand.
The house that has a basement and a crawl space. This is the county’s most common version of the problem. A 1960s ranch or split in Willingboro, 51.2% of which went up in that one decade, in Cinnaminson at 33.8%, or Delran at 46.3% across the 1960s and 70s, later gains a family room or bedroom wing over a shallow crawl while the original half keeps its basement. The two halves are vented differently, and the floor over the addition is the cold one every winter.
Rows over a shared crawl. Mount Laurel is 25.9% single-family attached, 5,178 townhouses and duplex halves, and Evesham 18.8%, against 14.5% countywide. Where a row sits over a crawl instead of a slab, the space usually carries straight past the party wall, so the liner and the drying method cover more than one address, and the owner or the association decides that scope.
The river-town houses with a cellar and a wing. Moorestown is 23.8% pre-1940 against the county’s 10.7%, Burlington Township 7.7%. Those houses often carry a stone cellar under the original block and a dirt-floored crawl under a kitchen wing added decades later, reached through a hatch in a closet floor.
Manufactured homes. The county holds 2,032 of them, 1.1% of all units and 6.1% of Pemberton Township. Skirting is not a stem wall, so the liner has nothing to seal to; there the work is the ground cover, the belly and the duct connections.
How we do crawl space encapsulation in Burlington County
Water comes before plastic. A liner over wet ground keeps the water underneath it, and a dehumidifier removes vapor, not puddles. The code wants the ground to fall at least 6 inches in the first 10 feet from the foundation, and where the water table can reach within 6 inches of the crawl space floor an approved drainage system goes in first. Gutters and downspouts get checked too. Interior drains, sump pumps and exterior waterproofing belong to a waterproofing contractor, a separate trade from ours.
Radon comes next, because a vented crawl dilutes it and a sealed one can let it collect. Test first, mitigate if the number calls for it, test again afterward. The federal guidance is to fix at 4 picocuries per liter and consider fixing between 2 and 4; the Department of Energy’s crawl space advice is to mitigate at 2 or more before closing. Mitigation and encapsulation share the same sheet of plastic: the radon pipe is laid under the membrane before it is sealed down. A natural-draft furnace or water heater down there needs its combustion air settled before the vents close.
Then the space gets cleared: vegetation, wood forms and debris out, as the code requires, and sagging floor batts down. Wet, settled or rodent-fouled insulation is bagged and removed under containment, and the reason it got wet is fixed first. Mold on the joists or the subfloor is remediation work for a remediation company, done before we seal anything in.
The liner is a Class I vapor retarder over every square foot of exposed earth, seams lapped at least 6 inches and taped, piers and pipes wrapped, and the edge carried at least 6 inches up the stem wall and sealed there. The code sets a class, not a thickness: 6-mil polyethylene meets it, and 10-, 12- or 20-mil reinforced liners buy puncture and tear resistance where somebody kneels to service a furnace or a sump. Vents are closed, rim joists air sealed and insulated, and the walls get closed cell foam at R-6.9 to R-7.1 per inch. Fiber does not go against a crawl space wall; it collects moisture and holds it.
Something has to dry the space, and the code lists four ways: a dehumidifier sized to its manufacturer’s specification, conditioned supply air at 1 cubic foot per minute for every 50 square feet of floor, a continuous exhaust fan at that rate, or the crawl run as a plenum, allowed only in an existing house. Choose before the liner goes down, because a dehumidifier needs a drain line on a constant fall and a grounded outlet, and most Burlington crawl spaces have neither. Wall foam can stay uncovered where the crawl is entered only for repairs and the product is tested for exposed use or given an ignition barrier; turn the space into storage and a thermal barrier is required. Foam plastic needs a permit in New Jersey, and we pull it as part of the job.
What crawl space encapsulation costs in Burlington County
Most of our projects run between $3,500 and $12,500. Ground area sets the base and access sets the labor: a stand-up crawl under a Medford contemporary and an 18-inch belly crawl under a Cinnaminson ranch are different days of work for the same square footage. The rest is how much old insulation and debris leaves the space, the liner thickness, the feet of stem wall and rim joist getting foam, the piers to wrap, and whether the drying method needs a drain line and an outlet run to it. Radon mitigation, drainage and pest work are priced by the trades that do them. Our insulation cost guide sets out the pieces.
Rebates for crawl space encapsulation in Burlington County
Six of the nine towns below buy both bills from PSE&G: Burlington Township, Cinnaminson, Delran, Moorestown, Mount Laurel and Willingboro. Pemberton Township takes electricity from JCP&L, with PSE&G gas reaching only a corner of it. Evesham and Medford are split on both meters, electricity between PSE&G and Atlantic City Electric, gas between South Jersey Gas and PSE&G. Two names on two bills means either company’s program can take the project; start with the one that bills your heating fuel, since the gas programs require gas heat.
The program is Whole Home Energy Solutions, and it pays on a scope rather than a product: air sealing plus the insulation the assessment calls for. Crawl space wall and rim insulation belongs in that scope; the liner, the drying equipment and any drainage are judged by the assessment, so ask what counts before the savings are modeled. PSE&G pays up to $7,500 with 0% on-bill repayment of up to $25,000, starting from an assessment by a BPI-certified contractor participating in its program, who sets that fee. JCP&L and South Jersey Gas publish the formula, $2,000 at a modeled 5% energy saving plus $200 for each point above it, capped at $7,500 and at half the project cost, each with 0% financing of $2,500 to $25,000. Atlantic City Electric pays up to $7,500 on single-family residences and finances through the program’s lender. Ask any installer, ourselves included, whether they participate in the program you intend to use.
Income-qualified households can have the work done at no cost: PSE&G Home Weatherization, or up to $14,000 in upgrades plus $2,500 in health and safety repairs at JCP&L, South Jersey Gas and Atlantic City Electric. New Jersey Comfort Partners serves households at or below 250% of the federal poverty guidelines, $82,500 for a family of four in 2026, and refers oil, propane and kerosene homes to the state’s weatherization office instead. New Jersey’s IRA Home Energy Rebates are not available; the state still lists them as in development. The federal 25C tax credit ended for anything placed in service after 31 December 2025. The rest is in our New Jersey rebate guide.
Code and climate in Burlington County
Burlington County is climate zone 4A, the milder of New Jersey’s two zones and a humid one, which is the condition that ruins vented crawl spaces: summer air carrying moisture into a space whose surfaces sit below its dew point. New Jersey adopted the 2024 IECC on 17 August 2026, and for a sealed crawl space it asks for R-10 continuous or R-13 cavity on the walls in the zone 4 counties, which closed cell foam reaches in about 1 1/2 inches. Walls may be left bare only where the crawl is vented to the outdoors and the floor above is insulated instead.
The residential code sets the rest. An unvented crawl space needs the sealed ground cover and one of the four drying methods together, not either alone. A crawl that stays vented needs 1 square foot of vent for every 150 square feet of floor, dropping to 1 in 1,500 once a Class I ground cover is down, so even a vented crawl earns its liner. Existing houses fall under New Jersey’s Rehabilitation Subcode, so sealing a crawl space does not oblige the rest of the house to meet current code. With 55.7% of this county built before New Jersey’s first statewide energy subcode of 1 January 1978, most of these crawl spaces answered to no insulation standard at all.
Towns we serve in Burlington County
Crawl space work runs county-wide, in all 40 municipalities. Nine of them carry their own page.
Common questions about crawl space encapsulation in Burlington County
Who are the crawl space encapsulation contractors near me in Burlington County?
We are one of them, working with our own crew from the river towns out to the Pinelands edge of Medford and Pemberton Township. An estimate means going under the house: headroom, ground condition, standing water, the floor batts, the stem walls, the vents, the piers, and whether anything down there burns fuel. You get a written scope naming the liner, the wall insulation, the drying method and the order the trades work in.
How much does crawl space encapsulation cost in Burlington County?
Most of our projects run between $3,500 and $12,500. A small, clean, stand-up crawl under one addition sits near the bottom. The number rises with square footage of ground, with access under 2 feet of headroom, with old wet insulation and debris that has to come out, with a heavier liner where equipment gets serviced down there, and with running a drain line and an outlet for a dehumidifier.
Do I need a dehumidifier in a Burlington County crawl space?
You need one of four drying methods, and a dehumidifier is the usual pick where the house has no easy way to supply conditioned air to the space. Size it to the manufacturer’s specification rather than a rule of thumb, and check the operating temperature: crawl spaces run cool, frost can form on the coils below 65 degrees, and units made for this work list minimums near 50 degrees. Target 30 to 50 percent relative humidity, and give the unit a drain line that falls the whole way.
Is a vapor barrier enough, or does my crawl space need full encapsulation?
A ground cover on its own stops moisture rising out of the soil. It does nothing about air coming through the vents, which in a humid zone 4A summer is the bigger load. Plastic down with the vents still open is a vapor barrier job, and the code still counts that crawl space as vented. Encapsulation adds sealed edges, closed vents, insulated walls and rim, and a drying method. We quote the vapor barrier version only where the floor above stays insulated.
Free energy audit in Burlington County
The crawl space visit happens on hands and knees with a flashlight and a moisture meter: the ground and what is on it, the joists and subfloor overhead, the batts and their hangers, the stem walls, the vents, the rim, the piers, the ductwork and any fuel-burning equipment, plus standing water and the grade outside that feeds it. Upstairs we walk the floors over the crawl and the rooms that never hold heat.
What comes back is a written scope and a price, free and without obligation. Call 914-554-2289, 8am–8pm, seven days. The Home Insulators is family-owned, has worked out of New Rochelle, NY since 2015, and puts its own 100-plus-person in-house crew on every job; we never subcontract.
Get my free estimateor call 914-554-2289, 8am–8pm every day