New Jersey cost guide
New Jersey contractors publish $4,500 to $12,000 for a typical crawl space and $12,000 to $18,000 and up with a drain and sump; the US average is $5,500 (Angi). In a FEMA flood zone, the flood openings must stay open.
The New Jersey figures are each company's own published prices; no New Jersey agency publishes encapsulation prices. Every figure was read on October 22, 2026 and is named to its source in the tables below.
Last updated October 22, 2026. LA Trusted Partners routes home-service requests to independent providers after your consent — it does not encapsulate crawl spaces, inspect, price, or guarantee the work. Every price below comes from a cited published source, with the date it shows or the date we read it. Flood rules come only from FEMA and New Jersey's own rules, code limits only from New Jersey's adopted residential code, and radon and moisture facts only from NJDEP and EPA. This guide covers crawl spaces, not basements.
The national guides agree on the middle of the market. Angi's July 10, 2026 average is $5,500, with most jobs $5,000 to $15,000. This Old House (updated March 13, 2026) also gives a $5,500 average and a wider $1,500 to $15,000 range, and HomeGuide (January 14, 2026) gives $3,000 to $15,000, or $3 to $10 a square foot.
New Jersey contractors that publish prices sit inside and above that band. First Call Contracting in Paramus lists $4,500 to $12,000 for a typical 800 to 1,500 square foot crawl with a liner, sealed vents, wall foam, rim joist and a dehumidifier, and $12,000 to $18,000 and up once a perimeter drain and sump are added. Attic Fanatics in Jackson gives $3,600 to $18,000 and up as its New Jersey starting points. Insulation4You, which works in New Jersey and Pennsylvania, prices wall and rim joist foam at $2,800 to $6,000 for a 1,000 square foot crawl and quotes full encapsulation on site.
So a New Jersey quote between about $4,500 and $12,000 for a dry crawl of ordinary size sits inside what local contractors publish. A quote near $18,000 should list a drain, a sump, mold work or wood repair line by line; if it does not, ask why.
| Source | Published price | Per square foot or average | Dated | What it covers |
|---|---|---|---|---|
| Angi, national | $5,000 – $15,000 | $5,500 average; basic $2 – $4, extensive $3 – $10 per sq ft | Updated July 10, 2026 | Size, condition, materials, labor and permits. Labor is 50% to 70% of the total. |
| HomeGuide, national | $3,000 – $15,000 | $3 – $10 per sq ft | January 14, 2026 | Itemized: inspection, cleaning or repairs, insulation, vapor barrier, sealing vents and holes, dehumidifier. |
| This Old House, national | $1,500 – $15,000 | $5,500 average; $3 – $7 per sq ft, up to $10 with extensive moisture | Updated March 13, 2026 | Labor, repairs, permits, vapor barrier by thickness, vents, insulation, dehumidifier, drainage, mold and pests. |
| First Call Contracting, Paramus, NJ | $4,500 – $12,000; $12,000 – $18,000 and up for a wet crawl | Typical 800 – 1,500 sq ft crawl | Page undated; read October 22, 2026 | Liner, sealed vents, wall foam, rim joist and a dehumidifier. A perimeter drain and sump move it to the higher range; mold and wood repair are priced on what is found. |
| Attic Fanatics, Jackson, NJ | $3,600 – $18,000 and up | Starting points for NJ encapsulation | Page undated; read October 22, 2026 | Cleanout, rodent exclusion, insulation, vapor barrier and full encapsulation, with moisture handled first. |
| Insulation4You, New Jersey and Pennsylvania | $2,800 – $6,000 walls and rim joist; $900 – $1,800 rim joist only | Closed-cell foam $1.20 – $2.75 per board foot | Page undated; read October 22, 2026 | 1,000 sq ft crawl space for walls and rim joist; 150 linear feet for the rim joist. Full encapsulation is quoted on site. |
Ranges are the linked sources' own published figures, each read live on October 22, 2026. Your price depends on the size, the condition and the scope — treat these as a comparison baseline, not a promise.
Every guide prices by area, so measure the crawl space first: length times width of the floor. Rows marked "by arithmetic" multiply the guide's own per-square-foot range by the size; the others are the guide's own table.
| Crawl space | HomeGuide (Jan 14, 2026) | Angi (Jul 10, 2026) | This Old House (Mar 13, 2026) |
|---|---|---|---|
| 500 sq ft | $1,500 – $5,000 (by arithmetic, $3 – $10 a sq ft) | $1,000 – $2,000 basic; $1,500 – $5,000 extensive (by arithmetic) | $1,500 – $3,500 (by arithmetic, $3 – $7 a sq ft) |
| 1,000 sq ft | $3,000 – $10,000 | $2,000 – $10,000 | $3,000 – $7,000 |
| 1,500 sq ft | $4,500 – $15,000 | $4,500 – $15,000 extensive (by arithmetic) | $4,500 – $10,500 (by arithmetic); labor alone $2,250 – $10,500 |
| 2,000 sq ft | $6,000 – $20,000 | $4,000 – $20,000 | $6,000 – $14,000 (by arithmetic) |
Per square foot: HomeGuide $3 – $10; Angi $2 – $4 basic and $3 – $10 extensive; This Old House $3 – $7, up to $10 with extensive moisture. Arithmetic is ours; the per-foot ranges are theirs.
Encapsulation is several jobs on one quote. The liner covers the dirt. The vents and gaps get sealed. The walls or rim joist may get foam. Something has to keep the air dry, usually a dehumidifier. And if water comes in, drainage comes first. Angi and This Old House both put labor at 50% to 70% of the total.
Two quotes for the same crawl can be far apart because they are not the same job. Lay them side by side against the lines below.
| Line on the quote | What it is | Published prices | Ask before you sign |
|---|---|---|---|
| Inspection | Someone crawls the space, measures it and checks moisture, mold, pests and wood | $100 – $250 (HomeGuide) | Is the inspection free, credited to the job, or billed on its own? |
| Cleanout and repairs | Debris, old insulation, standing water, rot or pests removed before anything is sealed | $500 – $8,000 if needed (HomeGuide); old insulation removal $1 – $2 a sq ft (HomeGuide); one-off crawl space cleaning $4,000 average (Angi) | What exactly is being removed, and is disposal included? |
| Vapor barrier (liner) | Plastic over the dirt floor and up the walls, seams sealed | $1,200 – $4,000 installed, about $2 – $4 a sq ft (HomeGuide); material $0.30 – $0.35 a sq ft at 6 mil up to $0.60 – $0.70 at 20 mil (HomeGuide) | What thickness (mil), how far up the wall, and are piers and seams taped? |
| Sealing vents and holes | Closing foundation vents, gaps and the access door | $150 – $450 (HomeGuide); vent covers $40 – $50 each installed (Angi); access door $60 – $150 (This Old House) | Is the house in a flood zone? If so, which openings stay open (see the flood-zone rule below)? |
| Insulation | Foam board or spray foam on the walls and rim joist | $500 – $3,700 (HomeGuide); NJ: walls and rim joist $2,800 – $6,000 for 1,000 sq ft, rim joist only $900 – $1,800 (Insulation4You) | Walls or the floor above? What R-value, and what product? |
| Dehumidifier | A unit that keeps the sealed space dry, with a drain line for the water | $1,000 – $3,500 installed (HomeGuide); $800 – $2,000 with wiring (This Old House) | What size (pints a day), where does the water drain, and is a new circuit needed? |
| Drainage and sump | An interior drain and a pump for crawls that take on water | $800 – $3,000 interior drain (HomeGuide); $600 – $1,800 full drainage (This Old House) | Where does the sump discharge, and is it separate from the dehumidifier drain? |
| Mold treatment | Treating growth on joists and the subfloor before sealing | $1,500 – $4,000 for a crawl space (HomeGuide); $1,000 – $3,500 (Angi); $500 – $4,000 (This Old House) | Will they show you photos of the growth before treating it? |
| Permit | The town's construction permit, if your municipality requires one | $50 – $250 (Angi); $100 – $250 (This Old House) | Who pulls the permit, and is the fee in the price? |
National: HomeGuide (January 14, 2026), Angi (July 10, 2026), This Old House (March 13, 2026). New Jersey: Insulation4You, read on October 22, 2026.
| Item | Published cost | Source |
|---|---|---|
| Drainage system repairs | $500 – $800 every five to ten years | Angi, Jul 10, 2026 |
| Routine crawl space inspection | $100 – $300 | Angi, Jul 10, 2026 |
| Mold inspection, if there was mold before | $150 – $300, every three to five years | Angi, Jul 10, 2026 |
| Routine cleaning after encapsulation | $150 – $300 every few years | Angi, Jul 10, 2026 |
Liners are sold by thickness in mil (thousandths of an inch). HomeGuide lists material at $0.30 to $0.35 a square foot for 6 mil and $0.60 to $0.70 for 20 mil (January 14, 2026). On a 1,000 square foot floor, by arithmetic, that is $300 to $350 of plastic against $600 to $700: the thickness alone does not explain a quote thousands of dollars higher.
This is the rule the national price guides leave out. FEMA's NFIP Technical Bulletin 1 (March 2020, the current edition on FEMA's technical bulletins page) says, in its own heading, that conditioned crawlspaces must have flood openings: "In SFHAs, all crawlspaces must have flood openings that meet the NFIP requirements and building codes." An SFHA is a Special Flood Hazard Area, the Zone A and Zone V areas on FEMA's flood maps.
The same bulletin notes that ordinary ventilation openings sit near the top of the wall and are usually too far above grade to count as flood openings. So in a flood zone, sealing the vents is not the issue; blocking or removing the flood openings is.
New Jersey's own rules point the same way. Section R408.7 of the State's 2024 residential code requires flood openings in the walls around an under-floor space in a flood hazard area, and New Jersey's flood hazard rules require an enclosure below the lowest floor that is built under a DEP permit to have permanent flood openings that meet the Uniform Construction Code (N.J.A.C. 7:13-12.5(p)3).
It can cost money at insurance time too. Technical Bulletin 1 says that if flood openings are not compliant, the floor of the crawlspace is treated as the lowest floor for flood insurance rating, which may raise NFIP premiums. FEMA has since changed how it rates policies — its October 2025 Flood Insurance Manual says base flood elevation is no longer a rating factor — so ask your flood insurance agent how a change to the openings would affect your policy before you sign.
Source: FEMA NFIP Technical Bulletin 1 (2020), sections 2, 7.1 and the residential code cross-reference, read October 22, 2026. Your town's floodplain administrator can tell you whether your house is in an SFHA and whether stricter local rules apply.
New Jersey builds one- and two-family homes to the International Residential Code, New Jersey edition. The Division of Codes and Standards lists the 2024/2023 codes as adopted August 17, 2026. Section R408 of the 2024 New Jersey edition gives a crawl space two legal paths.
Vented (R408.2): vent openings of at least 1 square foot for every 150 square feet of crawl space floor, one within 3 feet of each outside corner. With an approved Class I vapor retarder on the ground, the vent area can drop to 1 square foot per 1,500 square feet. By arithmetic, a 1,200 square foot crawl needs 8 square feet of vents, or 0.8 square feet with a liner.
Unvented, the code's word for a sealed crawl space (R408.3), needs all of this:
Why it matters for the bill: a quote that seals the vents but adds no exhaust, conditioned air or dehumidification does not match either path. Ask which path the contractor is building to.
Radon is a separate job from encapsulation, even though both start with plastic on the dirt. EPA's Consumer's Guide to Radon Reduction says the most effective way to reduce radon in a crawlspace home is submembrane suction: a high-density plastic sheet over the earth floor, with a vent pipe and fan drawing the radon from under it and venting it outdoors. A liner without the pipe and fan is not that system. EPA recommends fixing a home at 4 pCi/L or higher.
In New Jersey, NJDEP says that by law all businesses and professionals testing for or mitigating radon must be certified by the DEP; homeowners testing or mitigating their own home are the exception. NJDEP's radon testing page says high levels can occur anywhere in the state and recommends testing every home; a retail test kit should carry a New Jersey certification number starting with MEB9. So test before you encapsulate, and if the number is high, ask whether the contractor is DEP-certified for radon mitigation.
On moisture, EPA says to keep indoor humidity below 60 percent, ideally 30 to 50 percent, and that condensation on windows, walls or pipes can be a sign of high humidity. A humidity meter costs $10 to $50 (EPA). Put one in the crawl for a week before you buy anything.
When there is a moisture problem you can measure — humidity over EPA's 60 percent line, condensation, mold or water — yes, the fix is real. HomeGuide says encapsulation can lower energy bills 10 to 30 percent and pay back in 7 to 10 years, but its page gives no study for those numbers, so treat them as the publisher's claims, not a promise.
None of the guides in this article publishes a measured resale gain. What a New Jersey buyer does get by law is paperwork: NJDEP says the seller must give the buyer the results of any radon test and evidence of any mitigation when the contract of sale is signed. Keep the encapsulation contract, warranty and any permit with those papers.
Usually no. The Insurance Information Institute says standard homeowners policies exclude flood and do not cover damage from lack of maintenance, mold or pests. FEMA's flood policy gives only limited coverage in basements, and its basement fact sheet lists dehumidifiers that are not part of the heating and air conditioning system among excluded items.
Encapsulation is home improvement work. The New Jersey Division of Consumer Affairs' consumer brief on hiring a home improvement contractor (revised January 13, 2025) says contracts over $500 must be in writing with the contractor's legal name and business address, start and completion dates, a description of the work, the total price and the Home Improvement Contractor registration number. It also says to get warranties in writing with the brand or grade of materials, and that you can cancel a signed contract for any reason before midnight of the third business day after you receive your copy, in writing.
How to look a registration number up is in how to check a contractor in New Jersey.
Encapsulation controls moisture in a crawl space that is structurally sound. It does not fix a sagging beam, a cracked or bowing wall, or soil that is moving.
If the floor above is sagging or bouncy, the joists are soft, or the crawl space walls are cracked or leaning, that is a foundation repair question first. If water is coming in now, start with the water. If mold is growing on the joists, it is treated before anything is sealed; the mold remediation cost guide has the New Jersey prices.
LA Trusted publishes this cost guide so you can budget from published figures. It does not encapsulate crawl spaces, test for radon or guarantee the work, and it sets none of the prices above.
You describe the house, what you see in the crawl space and the town. Your contact information is shared with a matched independent provider only after you agree to the disclosure.
The inspection, the quote, materials, labor and any warranty come from the independent provider. LA Trusted's standards ask that a provider's business identity and service area be checkable, and that licensing where applicable, insurance evidence and complaint history be checked before routing.
This request is for foundation problems in or around the crawl space. Tell us who you are and where the house is, then note what you have seen: sagging floors, soft joists, cracked or bowing walls, or water coming through the foundation. We take it from there and an independent foundation provider calls you back. LA Trusted does not arrange crawl space encapsulation, so for moisture work alone, use the price checks above to choose a contractor yourself.
Coverage depends on the town and the job. LA Trusted does not do the work itself and does not promise a response time, so the quote and any warranty come from the provider who calls you. Ask for the total, including any inspection fee.
Already have a quote? Check it line by line. The foundation repair request page takes the same request.
Start a foundation request, price mold work, or check a contractor's registration.
New Jersey contractors that publish prices list $4,500 to $12,000 for a typical 800 to 1,500 square foot crawl space with a liner, sealed vents, wall foam, rim joist and a dehumidifier, and $12,000 to $18,000 and up when it also needs a perimeter drain and sump (First Call Contracting, Paramus). Attic Fanatics in Jackson gives $3,600 to $18,000 and up. Both read October 22, 2026. Angi's national average is $5,500, with most jobs $5,000 to $15,000 (July 10, 2026).
HomeGuide puts a 1,500 square foot crawl space at $4,500 to $15,000 (January 14, 2026). At This Old House's $3 to $7 a square foot, it works out to $4,500 to $10,500. In New Jersey, First Call Contracting's $4,500 to $12,000 range covers crawl spaces of 800 to 1,500 square feet, before any drain and sump.
HomeGuide gives $3,000 to $10,000, Angi $2,000 to $10,000 and This Old House $3,000 to $7,000 for 1,000 square feet. The spread comes from condition: a dry, clean space sits at the bottom; mold, water or rot pushes it up.
Angi puts basic encapsulation at $2 to $4 a square foot and extensive jobs at $3 to $10. HomeGuide gives $3 to $10, and This Old House $3 to $7, up to $10 with extensive moisture problems.
It is worth it when the crawl space has a moisture problem you can see or measure: damp air, condensation, mold, or water. EPA says to keep indoor humidity below 60 percent, ideally 30 to 50 percent. HomeGuide says encapsulation can cut energy bills 10 to 30 percent and pay back in 7 to 10 years, but it gives no study for those figures, so treat them as the publisher's claims.
None of the price guides in this article publishes a measured resale gain. HomeGuide says buyers see it as a sign of good maintenance but gives no figure. In New Jersey, the seller must give the buyer the results of any radon test and evidence of any radon mitigation when the contract of sale is signed (NJDEP).
Usually not. Encapsulation is an improvement, and the Insurance Information Institute says standard homeowners policies exclude flood and do not cover damage from lack of maintenance, mold or pests. Flood damage needs a separate flood policy, and FEMA says its flood policy gives only limited coverage in basements; a crawlspace with its floor below ground on all sides may count as a basement.
Not the flood openings. FEMA's Technical Bulletin 1 says that in Special Flood Hazard Areas all crawlspaces, including sealed conditioned ones, must have flood openings: at least two, with 1 square inch of open area per square foot of enclosed area unless engineered, the bottom no more than 1 foot above grade. New Jersey's residential code (R408.7) carries the same rule for under-floor spaces in flood hazard areas.
Yes. Section R408.3 of New Jersey's 2024 residential code allows an unvented crawl space if the earth is covered with a continuous Class I vapor retarder, lapped 6 inches and sealed, run 6 inches up the wall, and the space has continuous exhaust, conditioned air, or dehumidification sized to the maker's specifications. A vented crawl space needs 1 square foot of vent for each 150 square feet of floor, or 1 per 1,500 with a Class I liner (R408.2).
Not by itself. EPA says the most effective radon fix for a crawlspace home is submembrane suction: a high-density plastic sheet over the earth floor with a vent pipe and fan drawing the radon from under it. EPA recommends fixing a home at 4 pCi/L or higher. In New Jersey, by law, radon testing and mitigation businesses must be certified by the DEP; a homeowner may test or mitigate their own home.
It needs some way to keep the air dry. New Jersey's code lists four for an unvented crawl space: continuous exhaust, conditioned air, a plenum in an existing house, or dehumidification. A dehumidifier is the common choice on quotes; HomeGuide puts one at $1,000 to $3,500 installed.
No. A vapor barrier is the plastic on the floor. Encapsulation also seals the vents and gaps, runs the liner up the walls, and adds a way to keep the air dry. HomeGuide prices a vapor barrier alone at $1,200 to $4,000 installed and full encapsulation at $3,000 to $15,000.
It depends on the town and the work. Angi says it depends on your municipality and puts a permit at $50 to $250; This Old House says crawl space work usually requires one, at $100 to $250. Ask your town's construction office before work starts, and get in writing who pulls the permit.
Every source in this list was checked live, and every figure taken from it re-read, on October 22, 2026. Naming a company here is not an endorsement and does not mean it is an LA Trusted Partners provider.
Start with one documented request. You stay in control of whether your information is shared with a matched independent provider, and you get the total, including any inspection fee, before anyone starts.
