Crawlspace Repair Cost in Portland, OR
Most Portland crawlspace repairs run $1,525 to $12,325 depending on scope: a standalone vapor barrier starts around $3,225, full encapsulation runs $10,100 to $12,325. 2026 ranges for every service below, with the reference project, the inclusions, and the method behind them published in full.
Cost by Service
Every range below is a modelled estimate for the Portland/Vancouver metro in 2026, priced against a stated reference project rather than a national average — and it is an estimate, not collected quote data. The methodology page sets out the reference project, what each range includes and excludes, and the limitations. Click any service for the breakdown of what moves a project toward the low or high end.
| Service | Typical Range | What Pushes It to the High End |
|---|---|---|
| Vapor Barrier Installation | $3,225–$4,425 | Premium 20-mil cross-laminated barrier with wall coverage and double-sealed seams ($4,675–$6,375 total) |
| Crawl Space Drainage | $3,825–$6,800 | Complex hillside systems with multiple interceptors and long discharge runs ($7,225–$13,600) |
| Crawl Space Waterproofing Cost detail → | $3,825–$6,800 | Hillside lots with long discharge runs or significant existing flooding ($7,225–$10,100) |
| Sump Pump Installation Cost detail → | $1,525–$2,975 | Battery backup pump ($2,125–$3,825) or full drainage system with sump ($3,825–$6,800) |
| Crawl Space Encapsulation Cost detail → | $10,100–$12,325 | Dehumidifier, closed-cell rim joist foam, and full premium scope ($14,875–$20,400) |
| Insulation Replacement | $2,375–$5,525 | Spray foam on foundation walls, closed-crawl approach ($3,825–$7,650) |
| Mold Remediation | $1,525–$3,825 | Full-area remediation paired with encapsulation or drainage to fix the source ($5,525–$10,100 combined) |
| Basement Waterproofing | $7,225–$15,300 | Dual sumps, large dehumidifiers, and finish replacement ($17,000–$25,500) |
| Foundation Waterproofing | $21,250–$42,500 | Hillside lots with shoring, deep excavation, or difficult access (beyond $42,500) |
Prices assume an average 1,200 to 1,500 sq ft Portland-metro crawlspace in typical condition. See the cost drivers below for how your specific situation shifts these ranges.
Modelled estimates, last reviewed . These ranges are built from scope, materials and Portland-market labour time — they are not drawn from a database of contractor quotes, and this site does not hold one. How these figures are produced →
What Actually Moves the Price
These are the specific conditions that shift a quote up or down, with the dollar amount each one typically adds - not vague "it depends" language.
- Square footage : Crawlspaces under 500 sq ft typically run about 25% below the typical range for a given service; spaces over 1,500 sq ft run 30% to 60% above it.
- Crawl height and access : Tight clearance adds roughly $425 in labor time; very low clearance under 18" adds roughly $850.
- Standing water or moisture level : Damp conditions add about $680, active wet conditions add about $1,360, and standing water adds about $2,375 in extra prep before the main scope can start.
- Insulation removal : Wet or rodent-damaged insulation that must be torn out and disposed of before replacement adds about $2,375; a crawlspace with no existing insulation at all adds about $1,190 for the additional material.
- Discovered rot or structural repair : Wood rot found on joists or rim boards once the old vapor barrier or insulation comes out adds $350 to $1,275 per repair location - this is the most common reason a firm quote changes once work starts.
- Vapor barrier mil thickness : Upgrading from a code-minimum 10-mil to a 12-mil reinforced sheet adds $250 to $600; a premium 20-mil cross-laminated barrier with wall coverage brings the total vapor barrier line item to $4,675–$6,375.
- Dehumidifier : A standalone dehumidifier with the electrical work to run it adds $1,275 to $2,550 to an encapsulation project; supply-air ducting from an accessible furnace is sometimes the cheaper conditioning option instead.
- Rim joist air sealing : Closed-cell spray foam at the rim joists, typically required for full code compliance on a sealed crawlspace, adds $1,025 to $2,050.
- Hillside lots and drainage complexity : Curtain drains and multi-interceptor systems needed on hillside lots (common in Lake Oswego, West Linn, the SW Corridor, and Vancouver, WA) push drainage-heavy projects 20% to 40% higher, with complex systems reaching $7,225 to $13,600.
Why Portland Pricing Looks the Way It Does
Portland's wet season runs roughly November through spring, and the local water table rises into the top few feet of soil across most metro neighborhoods during that stretch. Clay-heavy soil doesn't drain well, so water moves laterally underground and finds the easiest path into a crawlspace: a foundation crack, a vent opening, or simply saturated ground beneath the house. That's the physical reason drainage and vapor barrier work dominate the pricing table above, rather than the cosmetic repairs a drier climate would prioritize.
Housing era matters as much as the weather. Pre-1940 homes in inner Portland neighborhoods like Sellwood, St. Johns, NE Alameda, Mt. Tabor, Laurelhurst, and Hawthorne often have low-clearance, dirt-floor crawlspaces with original old-growth Douglas fir joists and no working vapor barrier at all, which usually means a full retrofit rather than a partial fix. Tract homes from the 1970s through 1990s across Beaverton, Hillsboro, and Tigard typically have a degraded 4-mil or 6-mil poly barrier and sagging or rodent-damaged batt insulation - moderate-scope replacement work. Hillside lots in Lake Oswego, West Linn, and the SW Corridor carry the drainage-heavy premium scope described above, since they intercept groundwater flowing downhill toward the foundation instead of just sitting in saturated soil.
Licensing also shapes who can quote you a number in the first place. Oregon requires an active CCB (Construction Contractors Board) license for crawlspace repair work; Washington requires an L&I license, and the two don't transfer across the Columbia River. Two different parts of Oregon's Residential Specialty Code set the baseline, and they are worth keeping straight: R408 governs the under-floor space itself — either a vented crawlspace with a Class I vapor retarder over the ground, or a sealed one with one of three conditioning methods — while floor insulation R-values come from the energy chapter, not R408. A quote that doesn't meet the code baseline isn't a bargain, it's a project you'll likely pay to redo.
What a Proper Quote Should Include
A number without these details isn't a real quote yet - it's a guess. A licensed Portland-metro contractor's written quote should include:
- A written, line-item scope of work - not a verbal number or a one-line estimate.
- Materials specified by name and spec: mil thickness on the vapor barrier, R-value on insulation, pump horsepower, not just "vapor barrier" or "insulation."
- Your crawlspace square footage and clearance height noted, since both directly drive labor time.
- Labor and materials broken out separately, so you can see what you’re paying for.
- Permit status addressed if the scope requires one.
- Warranty terms in writing, including what’s covered and for how long.
- The contractor’s Oregon CCB or Washington L&I license number, so you can verify it yourself — it takes about two minutes and it is the single highest-value check in the whole process.
- No pressure to sign the same day the inspection happens.
Basic Projects vs Complex Projects
The spread across this table is mostly scope, not one contractor being expensive. It helps to think in three tiers rather than one number.
Basic
$1,525 – $4,425
One defined problem, one defined fix, no excavation. A sump pump in an existing basin, a standalone vapor barrier, a localized mold cleanup. Typically one to two days on site.
Standard
$3,825 – $12,325
Water management plus moisture control together: an interior perimeter drain with a sump, or a full closed-crawl encapsulation. Interior trenching, several days on site, and the tier most Portland homes with a real crawl space problem land in.
Complex
$14,875 – $42,500+
Exterior excavation, hillside drainage with multiple interceptors, or a whole-basement system. Heavy equipment, possible engineering, landscape restoration afterward, and the tier where a second opinion is worth the delay.
Two quotes that differ by thousands are usually quoting different tiers. The included-and-excluded table is the fastest way to work out which one you are holding.
What These Figures Assume, and What They Leave Out
The project being priced
- Size: 1,200 to 1,500 square feet of crawl space floor
- Condition: damp but without standing water at the time of the quote
- Access: a standard exterior or interior hatch with roughly 3 feet of working clearance
- Building: a single-family home on a continuous perimeter foundation
Excluded from every range
- Permit fees, which vary by jurisdiction and are usually billed at cost
- Structural repair of framing found to be rotten once the space is opened up
- Asbestos or lead abatement, which requires separately licensed contractors
- Electrical service upgrades where an existing panel cannot carry new equipment
- Landscape or hardscape restoration after exterior excavation
Per-service inclusion and exclusion lists, the definitions behind terms like “encapsulation” and “Class I vapor retarder”, the limitations of these figures, and the revision history are all on the cost methodology page.
Get a Range for Your Specific Crawlspace
Answer six quick questions for an estimate built from the same pricing on this page, adjusted for your square footage, condition, access, and insulation. Prefer the full-page version? Open the standalone calculator →
Crawlspace Cost Calculator
Answer 6 quick questions for a Portland-area price range based on 2026 contractor data.
This estimate is based on Portland metro 2026 pricing for projects of this size and scope. Actual costs vary by specific conditions and contractor. Get a free in-person inspection to confirm.
Sources
These establish the code a compliant scope has to meet, the incentives that offset part of it, the licensing and bonding overhead a legitimate Portland contractor carries, and the climate driving the demand. None of them prices this work — no published source does for this metro, which is why the ranges above are modelled rather than cited.
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Oregon Building Codes Division, 2023 Oregon Residential Specialty Code (ORSC) (2023 edition, based on the 2021 IRC)
Section R408 under-floor space requirements: ventilation openings and ratios for vented crawl spaces, Class I vapor retarder coverage and lap dimensions, and the three conditioning methods that permit an unvented crawl space.
Note: Effective October 1, 2023 (construction provisions mandatory April 1, 2024). Oregon has begun adoption of a 2026 edition, anticipated effective October 1, 2026 with a six-month phase-in, so verify the edition in force before relying on a section number.
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Energy Trust of Oregon, Oregon Residential Incentive Information Sheet (Form PI 320I, version 2026.4, effective January 1, 2026)
Every 2026 incentive figure quoted on this site: per-square-foot amounts for floor and wall/rim joist insulation by occupancy type and by state, the R-11-or-less existing floor insulation threshold and the R-30 insulate-to target, the R-4-or-less wall and rim joist threshold, the 60-day submission deadline, the paid-in-full invoice requirement, and the list of participating utilities.
Note: Energy Trust states incentives are subject to funding availability and may change. Confirm the current amount before budgeting around it.
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Oregon Construction Contractors Board, Licensing
Surety bond amounts by licence endorsement, including the increase applied to every endorsement effective January 1, 2024.
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NOAA National Weather Service, Portland, Portland Climate Book — precipitation normals (1991–2020 climate normals)
Portland-area rainfall totals and their seasonal distribution, the basis for every statement on this site about the wet season and its timing.
Sources last checked . Where a figure comes from a document that is revised on a schedule, the edition or version is named above so you can confirm it against the current one yourself.
Cost Guide FAQs
- Most Portland-area projects fall between $1,525 and $12,325 depending on scope. A standalone vapor barrier runs $3,225 to $4,425, a drainage-plus-sump system runs $3,825 to $6,800, and full closed-crawl encapsulation runs $10,100 to $12,325. Basement and foundation waterproofing run considerably higher, from $7,225 up to $42,500+ for a full-perimeter foundation excavation. The calculator below narrows the range for your specific situation; a free in-home inspection gives you an exact number.
- The cheapest common job is a standalone sump pump pump-only replacement at $600 to $1,025 (reusing an existing basin). The most expensive is full-perimeter foundation waterproofing on an existing home - $21,250 to $42,500 and beyond - because it requires excavating around the entire foundation. Between those extremes, most homeowners are looking at a vapor barrier, drainage system, or encapsulation project in the $3,225 to $12,325 range.
- It depends on the cause. Sudden, accidental water damage is sometimes covered; gradual moisture intrusion, groundwater seepage, and mold from long-term conditions usually are not, since most policies treat those as maintenance issues. Many Oregon insurance policies also carry an explicit mold cap, often $5,000 to $10,000, even on events that are otherwise covered. Document conditions with photos and a contractor’s written assessment before filing, and confirm your specific policy language with your carrier.
- Yes, on both sides of the metro, though the amounts differ. Crawlspace floor insulation upgraded to current code (R-30) and rim joist air sealing are eligible measures under Energy Trust of Oregon when installed on a home served by a participating utility. For an owner-occupied Oregon single-family home the 2026 floor insulation incentive is $0.75 per square foot; on the Washington side it runs through NW Natural at $1.25 per square foot. Existing insulation must be R-11 or less to qualify. See our 2026 Energy Trust rebate guide for the full amounts and filing deadlines.
- The calculator gives a realistic range based on the service, square footage, moisture condition, access, and insulation state you select - the same variables that drive the price ranges on this page. It cannot see hidden conditions like framing rot behind an old vapor barrier or the exact excavation depth a curtain drain needs, so a free in-home inspection from a licensed contractor is what turns that range into a firm, written number.
- Usually, yes, for drainage-related work specifically. Hillside lots in Lake Oswego, West Linn, the SW Corridor, and parts of Vancouver, WA intercept groundwater flowing downhill toward the foundation, which often requires a curtain drain in addition to interior perimeter drainage. That combination pushes drainage-heavy projects 20% to 40% above the typical range, with complex multi-interceptor systems reaching $7,225 to $13,600. Vapor barrier and insulation pricing is not meaningfully affected by hillside grade.
Get an Accurate Quote for Your Project
The cost calculator gives ranges. A free in-person inspection gives you an exact number. Connect with a licensed contractor today.