A wet basement can cost $250 to fix or more than $20,000, depending on where the water comes from and which repair a contractor proposes. Fixr puts the typical job at $3,000 to $10,000. This Old House puts a 1,000 square foot basement at $13,640.
This guide answers how much it costs to waterproof a basement by method, by size and by scope. It adds the costs that quotes leave out, such as mold cleanup, grading and permits, and it explains why two honest bids can sit thousands of dollars apart.
Every price names its source and date. New York City notes follow the national numbers.
Basement waterproofing cost at a glance
How much does basement waterproofing cost? Basement waterproofing costs $3,000 to $10,000 for most homeowners.
Average cost of basement waterproofing
Fixr’s February 2026 guide lists $3,000 to $10,000 with a typical average around $5,000. Bob Vila’s June 2024 article cites Angi’s national average of $4,920 in a range of $2,300 to $7,575. This Old House’s March 2026 figure is higher, at $13,640 for a 1,000 square foot basement in a range of $12,447 to $14,833. The guides do not say what each average includes, so the next section compares what each type of job costs.
- About $5,000 typical job, Fixr, Feb 2026
- $4,920 national average, Angi via Bob Vila, Jun 2024
- $13,640 average for 1,000 sq ft, This Old House, Mar 2026
Cost per square foot, and why it can mislead
Fixr prices waterproofing at $3 to $10 per square foot and damp proofing at $3 to $6. Bob Vila cites HomeAdvisor at $5 to $10 for waterproofing. Per square foot pricing can mislead, because a drain is priced per linear foot of wall. Two basements with the same floor area can have different perimeters and different totals.
| Type of work | Cost per sq ft | Source |
|---|---|---|
| Waterproofing, whole basement | $3 to $10 | Fixr, Feb 2026 |
| Waterproofing, HomeAdvisor figure | $5 to $10 | Bob Vila, Jun 2024 |
| Damp proofing | $3 to $6 | Fixr and Bob Vila |
| Waterproof paint and sealants | $1 to $8 | Fixr, Feb 2026 |
| Wall coatings | $3 to $12 | Bob Vila, Jun 2024 |
| Sodium bentonite, exterior | $2 to $5 | Fixr, Feb 2026 |
Cost by basement size, 500 to 2,000 square feet
How much does it cost to waterproof a 1,000, 1,500 or 2,000 square foot basement? Fixr lists $3,000 to $10,000 for 1,000 square feet, $4,500 to $15,000 for 1,500 and $6,000 to $20,000 for 2,000. This Old House lists higher ranges at every size it covers.
| Size | Range | Cost |
|---|---|---|
| 500 sq ft | $1,500 to $5,000 | |
| 750 sq ft | $2,250 to $7,500 | |
| 1,000 sq ft | $3,000 to $10,000 | |
| 1,250 sq ft | $3,750 to $12,500 | |
| 1,500 sq ft | $4,500 to $15,000 | |
| 2,000 sq ft | $6,000 to $20,000 |
| Basement size | Fixr, Feb 2026 | This Old House, Mar 2026 |
|---|---|---|
| 500 sq ft | $1,500 to $5,000 | $6,260 to $7,461 |
| 1,000 sq ft | $3,000 to $10,000 | $12,447 to $14,833 |
| 1,500 sq ft | $4,500 to $15,000 | $18,634 to $22,206 |
| 2,000 sq ft | $6,000 to $20,000 | $24,817 to $29,575 |
Bob Vila’s June 2024 table lists $5,000 to $10,000 for 1,000 square feet and $10,000 to $20,000 for 2,000.
Why do basement waterproofing quotes differ so much?
Why do quotes differ so much? Contractors price different jobs under the same name. A wall coating costs $1 to $8 per square foot, and a full interior drain with a pump costs thousands.
The table lists each type of job with its published price. A quote that covers only the first row and a quote that covers the last row are not comparable, even when both say “waterproofing.”
| Scope of work | What it does | Published price |
|---|---|---|
| Waterproof paint or coating | Treats the wall surface | $1 to $8 per sq ft |
| Crack injection | Seals one crack | $250 to $1,500 per crack |
| Interior perimeter drain | Drains water that reaches the basement | $40 to $120 per linear foot |
| Sump pump | Moves collected water outside | $600 to $2,500 |
| Vapor barrier | Controls moisture vapor | $1,500 to $3,000 |
| Exterior excavation and membrane | Treats the outside of the wall | $7,000 to $15,000 |
Fixr, February 2026, for paint, injection (low end), drain, pump and vapor barrier. This Old House, March 2026, for injection (high end) and exterior work.
The math shows how fast a drain job climbs. A 1,000 square foot basement measuring 25 by 40 feet has 130 feet of perimeter. At $40 to $120 per linear foot, the drain alone costs $5,200 to $15,600. Adding a pump at $600 to $2,500 brings the job to $5,800 to $18,100. That is an estimate built from Fixr’s published rates, not a quote, and it explains why This Old House’s $13,640 sits above Fixr’s typical range.
Basement waterproofing cost by method
What does each waterproofing method cost? Methods run from $1 per square foot for paint to $15,000 for a full exterior dig.
Waterproof paint and coatings
Waterproof paint and sealants cost $1 to $8 per square foot, per Fixr and This Old House. Bob Vila lists coatings at $3 to $12 per square foot and paint at $30 to $40 per gallon. It breaks interior sealants into acrylic at $3 to $4 per square foot, silicate at $4 to $6 and epoxy at $5 to $7. This Old House says paint reduces moisture but will not stop pressurized water, and that it needs reapplying every 5 to 10 years.
Crack injection and sealing
Fixr lists epoxy injection at $250 to $1,000 per crack. This Old House lists $800 to $1,500 per crack for a professional job and says foundation leak repair runs from $250 for a small crack to $10,000 for a major problem. Bob Vila says crack repair can add up to $7,000 on top of waterproofing. Fixr adds that epoxy can cost up to five times as much as acrylic sealants. DIY crack sealers last one season at most, per This Old House.
Interior drain and sump pump
An interior perimeter drain costs $40 to $120 per linear foot, per Fixr. This Old House lists interior weeping tile at $60 to $120. A pump installed costs $600 to $2,500 in Fixr’s waterproofing guide and $1,200 to $2,500 at This Old House.
- $1,400 average sump pump, range $800 to $2,000, Fixr, Jan 2025
- $500 to $1,200 to dig the pit, Fixr, Jan 2025
- $150 to $250 to add battery backup, Fixr, Jan 2025
Fixr’s sump pump page lists plumbers at $75 to $150 per hour and total labor at $300 to $4,000, depending on whether a pit and drain already exist.
Exterior excavation and membrane
Exterior waterproofing costs $7,000 to $15,000, per This Old House, and Bob Vila says a foundation membrane can reach $15,000. Fixr says total projects can reach $20,000. Excavation runs $50 to $200 per cubic yard and usually takes 2 to 3 days, per Bob Vila. This Old House says correctly done exterior work lasts for decades. No source I could open gives a reliable exterior price per linear foot, so this guide does not quote one.
Vapor barrier and dehumidifier
A vapor barrier costs $1,500 to $3,000, per Bob Vila and This Old House. Fixr puts the top at $4,000. Fixr lists a dehumidifier installation at $1,000 to $2,800. Both are add-ons for moisture control, priced separately from drains and pumps.
Waterproofing vs dampproofing: what are you paying for?
What is the difference between waterproofing and dampproofing? Dampproofing is the code’s default treatment for below-grade walls, and waterproofing is the stronger treatment required where a high water table or severe soil-water conditions are known.
The California Residential Code, section R406, follows the model International Residential Code on this point. R406.1 requires dampproofing of foundation walls that retain earth and enclose below-grade space, except where R406.2 applies. R406.2 requires waterproofing “in areas where a high water table or other severe soil-water conditions are known to exist.” Fixr prices dampproofing at $3 to $6 per square foot and waterproofing at $3 to $10, and says that unlike full waterproofing, dampproofing cannot withstand hydrostatic pressure. That makes it a poor fit for fully below-grade basements, high water tables and flood-prone sites.
| Item | Dampproofing | Waterproofing |
|---|---|---|
| Code section | R406.1 | R406.2 |
| When it applies | Default for walls that retain earth and enclose below-grade space | Where a high water table or severe soil-water conditions are known |
| Example materials | 3/8 inch Portland cement parging on masonry, then a dampproofing coat | Two-ply hot-mopped felts or 40-mil polymer-modified asphalt, among six listed systems |
| Withstands hydrostatic pressure | No, per Fixr | Yes, per Fixr |
| Price per sq ft | $3 to $6 | $3 to $10 |
Code text from the California Residential Code, section R406. Prices from Fixr, February 2026, and Bob Vila, June 2024.
Interior vs exterior waterproofing: cost, lifespan and cost per year
Is it better to waterproof a basement from the inside or outside? Interior work costs less, with an average of $3,000 at This Old House, and exterior work costs $7,000 to $15,000. The right choice depends on where the water enters and how much access the contractor has to the outside wall, so ask for a written diagnosis before choosing.
Side-by-side comparison
| Measure | Interior | Exterior |
|---|---|---|
| Average cost | $3,000 | $7,000 or more |
| Typical range | $2,000 to $6,000 | $7,000 to $15,000 |
| Unit prices | Drain $40 to $120 per linear foot, pump $600 to $2,500 | Excavation $50 to $200 per cubic yard, bentonite $2 to $5 per sq ft |
| Time on site | 1 to 3 days for most projects | Excavation usually 2 to 3 days |
| Published lifespan | Paint 5 to 10 years, sealants a few years | Decades when done correctly |
Averages and ranges from This Old House, March 2026. Unit prices from Fixr, February 2026, and Bob Vila, June 2024. Lifespans from This Old House. The same guide prices interior and exterior work together at $8,000 to $18,000.
Cost per year of protection
What is the cost per year of each waterproofing method? Only two methods have published lifespans, so only two can be priced per year. Waterproof paint costs $1 to $8 per square foot and lasts 5 to 10 years, which is $0.10 to $1.60 per square foot per year. Exterior work costs $7,000 to $15,000, and This Old House says it lasts for decades. If decades means at least 20 years, that is $350 to $750 per year. At 30 years it is $233 to $500.
- $0.10 to $1.60 per sq ft per year, paint over 5 to 10 years
- $350 to $750 per year, exterior work if it lasts 20 years
- $233 to $500 per year, exterior work if it lasts 30 years
No guide I could open gives a lifespan for an interior drain or pump, so this guide does not invent a per-year figure for them. The 20 and 30 year lines are assumptions, not published lifespans.
How to calculate your cost: perimeter, area and depth
How do you estimate waterproofing cost for your own basement? Measure the wall perimeter in feet, multiply it by the drain rate of $40 to $120 per linear foot, and add a pump at $600 to $2,500.
- Measure the length and width of the basement in feet
- Add them and double the result to get the perimeter
- Multiply the perimeter by $40 and by $120 for the drain range
- Add $600 to $2,500 for a sump pump
- Add $250 to $1,500 for each crack that needs injection
- Add related costs, such as grading or mold cleanup
| Size | Range | Cost |
|---|---|---|
| 1,000 sq ft | $5,800 to $18,100 | |
| 1,500 sq ft | $7,000 to $21,700 | |
| 2,000 sq ft | $7,800 to $24,100 |
Worked example: 1,000 square feet
A 25 by 40 foot basement has a perimeter of 2 x (25 + 40), which is 130 feet. The drain costs $5,200 to $15,600. A pump brings the total to $5,800 to $18,100. Three cracks at $250 to $1,500 each add $750 to $4,500, for a total of $6,550 to $22,600.
Worked example: 1,500 square feet
A 30 by 50 foot basement has a perimeter of 160 feet. The drain costs $6,400 to $19,200. With a pump, the total is $7,000 to $21,700.
Worked example: 2,000 square feet
A 40 by 50 foot basement has a perimeter of 180 feet. The drain costs $7,200 to $21,600. With a pump, the total is $7,800 to $24,100.
| Basement | Perimeter | Drain and pump estimate | Fixr whole-basement range |
|---|---|---|---|
| 1,000 sq ft, 25 x 40 ft | 130 ft | $5,800 to $18,100 | $3,000 to $10,000 |
| 1,500 sq ft, 30 x 50 ft | 160 ft | $7,000 to $21,700 | $4,500 to $15,000 |
| 2,000 sq ft, 40 x 50 ft | 180 ft | $7,800 to $24,100 | $6,000 to $20,000 |
Estimates multiply Fixr’s drain rate of $40 to $120 per linear foot by the perimeter and add its pump range of $600 to $2,500. Real basements are rarely exact rectangles.
The estimate’s high end passes Fixr’s ceiling at every size. Fixr’s range covers cheaper scopes, such as coatings and crack repair, so a full drain and pump job sits in the upper part of its range or above it.
French drain vs sump pump: differences and costs
What is the difference between a French drain and a sump pump? A French drain collects water, and a sump pump moves it out of the basement.
Do you need both?
Do you need both a French drain and a sump pump? Fixr and This Old House price the drain and the pump as separate lines, so a quote should show each one with its own price. A drain that collects water needs a place to send it, which is why many interior systems include a pump.
How many sump pumps does a large basement need?
No guide I could open gives a rule for the number of pumps. Ask the contractor to explain the count in writing. Fixr lists battery backup at $150 to $250 when added to an existing pump, so ask whether a backup is in the price.
Sump pump installation and replacement cost
Fixr’s January 2025 sump pump guide lists an average of $1,400 in a range of $800 to $2,000. Its waterproofing guide lists $600 to $2,500, This Old House lists $1,200 to $2,500, and Bob Vila lists $490 to $1,170. Labor depends on whether a pit and a drain already exist, which is why replacing a pump in an existing pit costs less than a new installation.
| Sump pump item | Cost | Source |
|---|---|---|
| Installed, average | $1,400 | Fixr, Jan 2025 |
| Installed, range | $800 to $2,000 | Fixr, Jan 2025 |
| Pit excavation | $500 to $1,200 | Fixr, Jan 2025 |
| Labor | $300 to $4,000 | Fixr, Jan 2025 |
| Battery backup add-on | $150 to $250 | Fixr, Jan 2025 |
| Pump unit, pedestal | $80 to $800 | Fixr, Jan 2025 |
| Pump unit, submersible | $90 to $1,000 | Fixr, Jan 2025 |
What raises or lowers the price?
What affects the cost of waterproofing a basement? Foundation type, wall height, soil and water conditions, the severity of the leak and local labor rates all move the price.
Foundation type and condition
Poured concrete costs least to seal, block costs more and stone costs the most, per This Old House and Fixr. Bob Vila says homes built before the 1960s may lack footings, and that block walls and needed foundation repairs add cost. This Old House lists foundation repairs at $2,000 to $8,500 and underpinning at $25,000 or higher. Fixr says older homes with deteriorated mortar joints may need costlier systems.
Water table, soil and hydrostatic pressure
High-water-table and flood-prone areas tend to cost more, per Bob Vila, and This Old House says clay soil pushes prices up. Fixr says heavy rainfall or snowmelt raises prices too. Water pressure limits cheap fixes. This Old House says waterproof paint reduces moisture but will not stop pressurized water.
Basement depth and access
Taller walls cost more. Fixr says 8 to 10 foot ceilings add cost, and This Old House says an 8 foot foundation needs heavier excavation. Excavation runs $50 to $200 per cubic yard and usually takes 2 to 3 days, per Bob Vila.
Severity of the water problem
Standing water removal costs $1,000 to $3,000, per Bob Vila. This Old House lists water damage repair at $1,360 to $6,290 and foundation leak repair at $250 for a small crack up to $10,000 for a major problem.
- $1,000 to $3,000 standing water removal, Bob Vila, Jun 2024
- $1,360 to $6,290 water damage repair, This Old House, Mar 2026
- $250 to $10,000 foundation leak repair, This Old House, Mar 2026
Labor and location
Fixr and This Old House put professional labor at about $200 per hour. Bob Vila lists $3 to $8 per square foot. Permits cost $75 to $500, per Fixr.
What is the cheapest way to waterproof a basement?
What is the cheapest way to waterproof a basement? Move roof water away from the foundation first, then seal only the spots that leak. Bob Vila advises extending downspouts 8 feet or more from the basement and waterproofing only the areas that actually leak.
DIY vs professional
This Old House lists these jobs as reasonable for a homeowner: waterproof paint on clean walls, dehumidifiers, sealing hairline cracks with store-bought compounds, gutter cleaning and downspout extensions. It says to hire a professional for drainage systems, foundation excavation, sump pump installation and anything involving electrical wiring or concrete. Fixr warns that excavating around a foundation yourself is extremely risky.
| Task | Who does it | Published cost |
|---|---|---|
| Waterproof paint | Homeowner | $30 to $40 per gallon, $1 to $8 per sq ft |
| Hairline crack sealing | Homeowner | Store-bought compound, price not published |
| Downspout extensions and gutter cleaning | Homeowner | Gutter cleaning $200 to $400 per visit if hired |
| Interior drain and pump | Professional | $40 to $120 per linear foot, pump $600 to $2,500 |
| Exterior excavation | Professional | $7,000 to $15,000 |
Task guidance from This Old House, March 2026. Prices from Fixr, February 2026, Bob Vila, June 2024, and This Old House. Bob Vila lists DIY equipment rental at about $75 to $350 per day and says some manufacturers void warranties if a licensed professional does not install the product.
When a cheap fix fails
Waterproof paint will not stop pressurized water, per This Old House. Sealants may last only a few years, and DIY crack sealers last one season at most. A fix that fails costs the original price plus the damage it did not prevent.
Signs you need waterproofing, and when dampproofing is enough
How do you know a basement needs waterproofing? Look for these signs, which Bob Vila, This Old House and Fixr list between them.
- White powder on walls or floors, called efflorescence
- Water stains or discoloration on walls, floors, baseboards or carpet
- Musty or earthy odors
- Standing water on the floor after rain
- Water pooling in the yard, driveway or garden beds near the house
- Rust on drain pipes, pipe hangers or other metal
- Foundation cracks, bowing walls or horizontal cracks
- Visible mold growth
Bob Vila notes that efflorescence is harmless in itself, but the water that left it behind may not be. Dampproofing is enough only for minor moisture. Fixr says it handles minor moisture and cannot withstand hydrostatic pressure, and Bob Vila says most modern homes already have some dampproofing and that it does little against groundwater.
What happens if you do not waterproof a basement?
What happens if you do not waterproof a basement? Water damage costs follow, and the guides price them: mold cleanup, water damage repair and structural repair. None of the guides gives the odds that any one of these will happen.
| Possible result | Published cost | Source |
|---|---|---|
| Mold remediation | $500 to $6,000 | Fixr and Bob Vila |
| Water damage repair | $1,360 to $6,290 | This Old House |
| Structural damage repair | $2,500 to $25,000 | Fixr |
| Underpinning | $25,000 or higher | This Old House |
Bob Vila advises not to ignore warning signs, because addressing water damage early prevents more expensive repairs later.
Should you waterproof before finishing a basement?
Should you waterproof before finishing a basement? Yes, waterproof first. This Old House advises waterproofing before installing drywall or flooring so you do not have to redo finished work.
Will insurance pay for basement waterproofing?
Will insurance pay for basement waterproofing? No, most homeowners policies do not cover waterproofing work, per Bob Vila. Water damage may be covered when a covered event causes it.
Standard homeowners insurance
Amica says maintenance and repair are generally the homeowner’s responsibility, and that slow leaks are usually not covered. It lists groundwater seepage through the foundation as an exclusion, so a policy generally will not pay for water that seeps through a wall.
Water backup and sump pump endorsements
A water backup endorsement adds coverage for repairs to walls and floors, damaged personal property, and cleanup, drying and mold prevention, per Amica. The same page excludes normal wear and tear of plumbing and sump pumps, although resulting water damage may be covered. Ask the agent which events the endorsement covers and what limit applies.
Flood insurance
Amica says surface flooding needs separate flood insurance. Neither a standard policy nor a backup endorsement covers it.
Is basement waterproofing worth the cost?
Is waterproofing a basement worth the cost? It is worth it when water reaches the basement, because the guides price the damage at $1,360 to $25,000 and more. This Old House says waterproofing adds usable space and improves resale value. Bob Vila says it may or may not raise a home’s value, and that solving a moisture problem can make a home more appealing to buyers. No source I could open gives a percentage return.
Tax treatment: repair or improvement?
IRS Publication 523 for 2025 returns says improvements add to a home’s tax basis and repairs do not. It names fixing leaks and filling holes or cracks as repairs, and it does not list waterproofing among its improvements. A new drainage system may count as an improvement and a crack repair as a repair, but the publication does not say so. Ask a tax professional before assuming either.
Does waterproofing increase home value?
The guides give no fixed amount. This Old House says waterproofing improves resale value without giving a number, and Bob Vila says it may or may not raise value. Ask a local real estate agent how buyers in your area treat a disclosed wet basement.
Basement waterproofing cost in New York City
How much does it cost to waterproof a basement in New York City? The only New York City price I found is five years old: HomeBlue’s page, last updated October 2021, lists $4,300 to $17,300 for the whole job. That is about 1.7 times Fixr’s national ceiling of $10,000.
| New York City item | HomeBlue, Oct 2021 | 130 ft perimeter, estimate |
|---|---|---|
| Whole job | $4,300 to $17,300 | Not applicable |
| Exterior foundation waterproofing | $184 to $260 per linear foot | $23,920 to $33,800 |
| Basement French drain | $108 to $130 per linear foot | $14,040 to $16,900 |
| Basement sealing | $8.70 to $17.30 per sq ft | Priced by wall area |
HomeBlue is a cost-estimate site, and its figures are four to five years old. The 130 foot column multiplies its per-foot rates by the 25 by 40 foot example from earlier. Treat all of it as a rough guide.
The New York City Department of Buildings says permits are required for most excavation work, including underpinning, and that contractors must give the department 24 to 48 hours of notice before excavating. Its excavation page does not mention waterproofing. Exterior work that digs down to the footing is likely to involve a filing. Interior-only work may not. Ask the department or a licensed contractor to confirm before work starts.
How to get and compare quotes
How should you compare basement waterproofing quotes? Get at least three written bids, per Bob Vila, This Old House and Fixr, and compare them line by line on the same scope.
An itemized quote checklist
- The method, and why it fits this basement
- Footage of drain and the rate per linear foot
- Sump pump price, pit work and battery backup
- Number of cracks and the price per crack
- Vapor barrier or dehumidifier, if included
- Grading, gutters and downspout work
- Permits and who files them
- Cleanup after the work
- Any chance of additional costs
- Warranty terms, and whether the warranty transfers to a new owner
Red flags in a low quote
- A single lump sum with no footage or per-unit prices
- A coating-only price for a basement with water pressure, since waterproof paint will not stop pressurized water
- No pump line on a job that moves water, when a pump costs $600 to $2,500
- No written reason the method fits your basement
- A product warranty that requires a licensed installer, when the installer is not licensed
Questions to ask a contractor
Bob Vila suggests asking for proof of insurance, how long the company has been in business, references for similar projects, which products it uses, whether it handles cleanup, whether additional costs are possible, why the method fits your home and whether it offers a warranty. This Old House says professionals typically back their work with a warranty and gives no length. Ask for the length and the transfer terms in writing.
Basement waterproofing cost FAQs
How long does interior drain installation take?
Bob Vila lists a typical project at 1 to 3 days, and longer when excavation is needed. Exterior excavation usually takes 2 to 3 days.
Is waterproofing paint effective?
Waterproof paint reduces moisture but will not stop pressurized water, per This Old House. It costs $1 to $8 per square foot and needs reapplying every 5 to 10 years.
What are my options if water comes from below the slab?
The guides price an interior perimeter drain at $40 to $120 per linear foot and a sump pump at $600 to $2,500 for water that reaches the basement. Fixr says dampproofing cannot withstand hydrostatic pressure. Ask a contractor to diagnose where the water enters before choosing a method.
How much does it cost to seal a foundation crack?
Epoxy injection costs $250 to $1,000 per crack at Fixr and $800 to $1,500 at This Old House. This Old House lists foundation leak repair at $250 for a small crack. For masonry repair in New York City, see Rockzen USA’s masonry contractor page.
How long does waterproofing last?
This Old House says paint needs reapplying every 5 to 10 years, sealants may last a few years and correctly done exterior excavation work lasts for decades. No source I could open gives a lifespan for an interior drain or pump.
Bottom line and next steps
How much does it cost to waterproof a basement? Most homes pay $3,000 to $10,000, with an average near $5,000, and this guide’s estimate for a full drain-and-pump job on a 1,000 square foot basement reaches $18,100.
| Question | Answer |
|---|---|
| Typical total | $3,000 to $10,000 |
| Average | About $5,000 |
| Per square foot | $3 to $10 |
| Interior drain | $40 to $120 per linear foot |
| Sump pump | $600 to $2,500 |
| Exterior excavation | $7,000 to $15,000 |
| Insurance | Usually no for waterproofing work |
- Find where the water enters, and fix gutters and downspouts first
- Measure the perimeter and estimate the drain and pump cost
- Get three written quotes that follow the same checklist
- Ask about permits, warranty length and transfer terms
- Finish the basement only after the water is under control
Match each quote to the source of the water before you compare prices.
Sources
- Fixr: How Much Does It Cost to Waterproof a Basement? (updated 6 February 2026)
- Fixr: Sump Pump Installation Cost (updated 31 January 2025)
- This Old House: Basement Waterproofing Cost (updated 4 March 2026)
- Bob Vila: Basement Waterproofing Cost (updated 14 June 2024)
- Amica: Water Backup Coverage
- IRS: Publication 523, Selling Your Home (2025)
- California Residential Code: Section R406, Foundation Waterproofing and Dampproofing
- HomeBlue: Basement Waterproofing Cost in New York, NY (updated 26 October 2021)
- NYC Department of Buildings: Excavation
