How much does basement waterproofing cost in Ontario, CA?

Most Ontario homeowners spend between $3,150 – $12,600 on basement waterproofing, with an average around $6,850. Local labor prices 5% above the national average, so Ontario quotes tend to land at the higher end of national ranges.

How many quotes should I get in Ontario?

Get at least three written quotes from licensed, insured California contractors. Comparing line items — not just the bottom line — is the fastest way to spot an inflated bid in the Inland Empire market.

How much does basement waterproofing cost?

$3,000 to $12,000 on average. Interior drainage is $3,000 to $10,000; exterior excavation is $8,000 to $25,000.

Interior or exterior waterproofing?

Interior drain tile manages water that gets in and costs far less. Exterior membrane keeps water out entirely and is the permanent fix, at two to three times the price.

How much is a sump pump?

$1,000 to $3,000 installed, plus $500 to $1,500 for a battery backup that keeps working during a storm outage.

Is waterproofing covered by insurance?

Groundwater seepage is excluded from standard homeowners policies. Separate flood insurance or a water backup endorsement is required.

Will waterproofing fix mold?

It stops the moisture source, but existing mold needs separate remediation, typically $1,500 to $6,000.

Does a dry basement add value?

Yes — a documented, warrantied waterproofing system removes a major buyer objection and enables finishing the space.

Home/Cost guides/Basement Waterproofing/Ontario, CA

Inland Empire · California

Basement Waterproofing cost in Ontario, CA

Ontario homeowners typically pay $3,150 – $12,600 for basement waterproofing. Local labor and materials price 5% above the national average.

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Ontario average

$6,850

Typical low

$3,150

Typical high

$12,600

Per linear foot

$42 – $265

Sample ZIP

91761

What drives Ontario pricing

Local labor

Licensed Ontario contractors carry California workers' comp and prevailing wage pressure, and crews here quote roughly 5% above the national labor average. Demand in the Inland Empire market peaks in spring, so booking early usually beats a rush premium.

Permits & code

Ontario follows the California Building Standards Code, so most structural, electrical, plumbing and re-roof work needs a permit from the Ontario building department plus Title 24 energy compliance. Inland Empire jurisdictions add high-wind and fire-hardening requirements in foothill zones.

Climate & conditions

Ontario sits in a hot, dry inland climate with Santa Ana wind events, so expect wind-rated fasteners, fire-resistant materials and heat-tolerant finishes.

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Wall length to treat80 linear feet

Method

Foundation depth

Exterior access

Water problem

Estimated project cost

$420 – $1,280

Most homeowners pay around $850

Compare method

Cost by material in Ontario

Installed Ontario pricing per linear foot.

Option	Installed cost	Pros	Cons
Interior sealant	$5 – $16	Cheapest, DIY possible	Cosmetic — does not stop hydrostatic pressure
Interior drain tile + sump	$42 – $105	Effective, no landscaping destroyed, done in days	Relies on a pump and power
Exterior membrane	$105 – $265	Stops water before it reaches the wall — the permanent fix	Most expensive and disruptive
Crawlspace encapsulation	$21 – $63	Controls humidity, mold and energy loss	Needs a dehumidifier to keep working
Wall reinforcement	$84 – $210	Addresses bowing plus water together	Structural scope and engineering

Where the money goes in Ontario

A typical $6,850 Ontario project, broken down by line item.

Labor and excavation50% · $3,425
Drainage materials22% · $1,507
Sump pump and equipment16% · $1,096
Concrete restoration and disposal12% · $822

Common add-ons

Extras that show up on Ontario quotes but rarely in the headline price.

Sump pump

$630 – $2,100

Battery backup

$525 – $1,600

Dehumidifier

$1,250 – $3,150

Mold remediation

$1,600 – $6,300

Vapor barrier

Per square foot

$2 – $6

Egress window

$2,650 – $6,300

Ways to save in Ontario

Do the cheap exterior fixes first — gutters, downspout extensions and grading solve many wet basements for under $1,000.
Choose interior drain tile over exterior excavation unless the wall itself is failing.
Get bids from waterproofing specialists and a general contractor; approaches and prices differ enormously.
Ask about a transferable lifetime warranty — it holds value at resale.
Install the sump and drainage before finishing the basement, never after.

Ontario FAQs

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More Ontario research

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Basement Waterproofing cost near Ontario

Basement Waterproofing cost in Riverside, CA

$3,180 – $12,720

Basement Waterproofing cost in San Bernardino, CA

$3,090 – $12,360

Basement Waterproofing cost in Temecula, CA

$3,240 – $12,960

Basement Waterproofing cost in Eastvale, CA

$3,240 – $12,960

Basement Waterproofing cost in Rialto, CA

$3,060 – $12,240

Basement Waterproofing cost in Victorville, CA

$2,970 – $11,880

More California cities

Los Angeles San Diego San Jose San Francisco Oakland Sacramento Fresno Long Beach

Other project costs in Ontario

Fence Installation in Ontario

$1,575 – $4,200

Roof Replacement in Ontario

$8,925 – $35,700

Kitchen Remodel in Ontario

$18,900 – $99,750

HVAC Replacement in Ontario

$5,775 – $18,900

Deck Building in Ontario

$4,620 – $12,600

Window Replacement in Ontario

$473 – $1,575

See every Ontario cost guide