Basement Waterproofing Cost in Los Angeles [2026 Data]

With the average basement waterproofing cost in Los Angeles at $4,398, homeowners can expect to pay between $2,992 and $6,038 for different types of waterproofing solutions. Generally, the type of basement in a home, the size of a basement, and the homeowner's preferences for interior versus exterior waterproofing solutions determine final costs for a project of this scope. Keep reading to learn more about what you can expect to pay when hiring a pro to waterproof your basement in Los Angeles.

Basement Waterproofing Cost Factors 

During a consultation with a basement waterproofing contractor in Los Angeles, CA, homeowners can receive suggestions for how to waterproof their basements based on factors like property slope, evidence of signs of basement water damage, and more. With basements being less common than concrete slabs due to earthquake-safety practices, common basement waterproofing options like sealants, weeping tiles, and exterior French drains can be applied to slabs in Los Angeles. 

Basement Size

The cost to waterproof a basement falls between $3 and $10 per square foot on average, although where in this range your pricing falls depends largely on the type of waterproofing method you choose. In any case, large spaces require more time, labor, and material to waterproof than small spaces. Therefore, the larger your basement, the more you can expect to pay for waterproofing for any given method.

Below is a breakdown of how much you might spend for a range of basement sizes.

Interior vs. Exterior Waterproofing

Depending on where your basement water issues are stemming from and what solutions your expert recommends, you may need either interior or exterior waterproofing services. Some homes require both. Interior basement waterproofing is often more affordable because it doesn’t involve excavation and backfilling. Something like installing damp-proofing around the exterior of your foundation would require a lot of digging, which drastically increases labor costs.

You’ll spend an average of $3,000 on interior waterproofing services, while extensive exterior services will cost an average of $7,000.

Waterproofing Method

As mentioned above, professionals can waterproof your basement from the exterior or the interior. Exterior methods are more effective because they’re preventative, but they’re also more expensive because they tend to require excavation, which is time-consuming. The table below includes a list of basement waterproofing methods along with cost ranges for each.

Basement Waterproofing Pro Costs

Basement waterproofing pros in Los Angeles set rates based on the scope of the project to account for factors like material costs, permit requirements, and labor costs.

Permits

With the exception of applying sealants and membranes to foundations, nearly all basement waterproofing work requires a permit in Los Angeles. For example, adding a drainage system requires plumbing work. Any excavation work needed to install drainage or rebuild parts of a basement will also require permits. Your basement waterproofing contractor will handle permits by submitting plans to the Los Angeles Department of Building and Safety (LADBS). On average, permit costs for basement waterproofing in Los Angeles can total between $300 and $2,000.

Local Labor

Los Angeles contractors typically charge between $170 and $190 per hour. However, larger projects are generally bundled either by square foot or under a flat-rate cost that takes into account all materials, equipment, and labor needed to get the job done.

Taxes

While the labor for basement waterproofing is exempt from sales taxes in Los Angeles, contractors will pass down the sales taxes that apply to all materials for this project to the homeowner. That means that homeowners should budget for a 9.75% total sales tax rate that takes into account a 6% California sales tax, 0.25% Los Angeles County sales tax, 1% Los Angeles sales tax, and 2.5% special Los Angeles County District Tax.

Insurance

California requires all contractors to possess general liability insurance. If a contractor has employees, they must carry workers' compensation under California law. With these costs escalating, the general cost of doing business for contractors by $150 to $325 monthly on average, homeowners should expect slightly higher labor rates.

Licensing and Certification

With the law requiring all California contractors to be licensed by the California Contractors State License Board (CSLB) for any project valued at $500 or more, local professionals must pay for training and testing prior to going into business. Between the exam fee of $450 and the initial license fee of $200, most contractors spend up to $1,000 to $2,000 just to start their businesses. In addition, license renewal registration and fees can cost $450 to $750 for various specialties. 

Does Basement Waterproofing Increase Home Value?

Is basement waterproofing worth it? Most estimates place the return on investment (ROI) for waterproofing a basement in Los Angeles at 70% to 80%. Whether a home has a full basement or slab foundation, waterproofing efforts go a long way toward the value of a home because the risk for earthquakes makes having a solid, intact foundation critical. 

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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