Looking for a basement waterproofing contractor in St. Helena, CA? Describe your project once and up to three waterproofing contractors who work in St. Helena and Napa County get back to you with a quote. It's free and there is no obligation.
St. Helena is home to about 5,257 people (2024 Census Bureau estimate), a shrinking community (−3.2% since 2020). With 1,060 people per sq mi, it is a suburban area. Heavy rains, high water tables and older foundations are the usual causes of wet basements here.
St. Helena at a glance
- Population (Census Bureau estimate, 2024)
- 5,257 (−3.2% since 2020)
- Rank in California
- 423rd of 482 cities and towns
- Land area
- 5.0 sq mi
- Population density
- 1,060 people per sq mi (suburban)
- Type
- City (St. Helena city)
- Main county
- Napa County
What to check before hiring in St. Helena
- Outside first: check gutters, downspouts and grading before paying for a system.
- License and permit: in California, check the contractor's license and whether a permit is needed.
- Warranty: ask what it covers, whether it is transferable and who backs it.
- Price drivers: wall length, system type, sump pumps and excavation.
Useful official resources
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EPA: mold
Official information and guidance.
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ICC: International Code Council
Official information and guidance.
Services available in St. Helena
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Interior drain tile and sump pump
Interior perimeter drain, sump pump and vapor barrier to keep water out of the basement.
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Exterior waterproofing
Excavation, membrane and footing drain on the outside of foundation walls.
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Basement crack sealing
Injection or sealing of leaking cracks in poured or block foundation walls.
Frequently asked questions in St. Helena
How much does basement waterproofing cost in St. Helena, CA?
It depends on the system and the size of the basement. Describe the problem: contractors who serve St. Helena reply with a quote.
How long does it take?
Interior systems often take a few days; exterior work takes longer.
Will waterproofing stop mold?
It removes the main cause. Existing mold should be cleaned up separately.
Which waterproofing contractors will contact me?
Up to three independent waterproofing contractors who serve St. Helena and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.