HomeGuide's national guide, written January 23, 2026, puts the average cost of basement waterproofing at $6,000 to $18,000, with interior work at $6,000 to $12,000 and exterior work at $10,000 to $18,000. No guide publishes verified Annapolis prices, so this post sets out what the guides say, how the methods differ and what moves the number on a real house.
The Short Answer
A small fix such as regrading or a downspout costs hundreds to a few thousand dollars. A drainage and sump system costs thousands, and excavating and coating the outside of the foundation costs more. Annapolis MD Basement Waterproofing prices every job after an on-site inspection, because where the water enters and how much wall needs work decide the total.
Compare the Prices
| Job | National figure | Source |
|---|---|---|
| Basement waterproofing overall | $6,000 to $18,000 average | HomeGuide, written January 23, 2026 |
| Interior waterproofing | $6,000 to $12,000 average | HomeGuide, January 23, 2026 |
| Exterior waterproofing | $10,000 to $18,000 average | HomeGuide, January 23, 2026 |
| Exterior French drain | $30 to $90 per linear foot, with installation | HomeGuide, January 23, 2026 |
| Sump pump installation | $600 to $2,500 or more | HomeGuide, January 23, 2026 |
| Epoxy crack injection | $250 to $800 or more per crack | HomeGuide, January 23, 2026 |
| Sealers (waterproof paint, concrete sealing) | $2 to $10 per square foot | HomeGuide, January 23, 2026 |
| Regrading | $1,000 to $5,000 | HomeGuide, January 23, 2026 |
| Downspout replacement | $220 to $625 | HomeGuide, January 23, 2026 |
| Crawl space encapsulation | $3 to $10 per square foot, or $3,000 to $15,000 | HomeGuide, written January 14, 2026 |
| Crawl space drain | $800 to $3,000 | HomeGuide, January 14, 2026 |
| Mold remediation | $1,500 to $15,000 | HomeGuide, January 23, 2026 |
HomeGuide also lists an interior French drain at $4,000 to $17,000 on average, which runs above its own $6,000 to $12,000 interior total, so we do not use that figure as a single number.
What Moves the Price
HomeGuide names these cost drivers: the foundation type, the size of the basement, the type and severity of the problem, the method, and the location. In practice, these decide the total:
- The foundation type. Poured concrete is generally cheaper to waterproof than block, and stone is the most expensive.
- The method. Interior options usually cost less than excavation-based exterior work, and combining methods raises the total.
- How the water enters. Several entry points or a lot of pressure cost more than one seep.
- Access. Exterior work needs room to dig around the foundation.
- Extras. A dehumidifier is $130 to $300 for a portable unit and $1,500 to $3,500 for a whole-house unit.
Annapolis Conditions That Affect the Job
The NOAA climate normals for the Annapolis NAF, MD station (1991-2020) record 43.99 inches of precipitation a year. According to the Maryland Geological Survey, most wet basements are caused by foundation, landscaping and grading issues, not by rising groundwater. When the cause is outside the wall, regrading or a downspout fix can cost less than a system, according to the figures above. Census Bureau figures (American Community Survey, 2020-2024) show that about 59% of occupied Annapolis homes were built before 1980, and the median owner-occupied home is worth $548,900. Why is my basement wet
What a Fair Quote Lists
A quote compares with another only when both describe the same work. Look for where the water enters, the length of wall or drain, the pump and the discharge, the warranty in writing, the contractor's MHIC license and who handles any permit. How to compare waterproofing quotes
Frequently Asked Questions
How much does basement waterproofing cost in Annapolis?
HomeGuide's January 2026 national guide puts the overall average at $6,000 to $18,000, with interior waterproofing at $6,000 to $12,000 and exterior at $10,000 to $18,000. Those are national averages, not Annapolis quotes. An on-site inspection gives the number for a specific house.
Why is exterior waterproofing more expensive than interior?
Exterior work means excavating around the foundation, and HomeGuide says interior options usually cost less than excavation-based exterior work. Exterior drains and membranes both require digging around the perimeter. Interior vs exterior waterproofing
Is a basement inspection free?
Inspections are priced by the company. Annapolis MD Basement Waterproofing offers a free, no-obligation inspection with every estimate.
Can a cheaper fix stop the water?
Sometimes. HomeGuide says regrading is occasionally enough on its own, at $1,000 to $5,000, and lists downspout replacement at $220 to $625. We check the outside first and tell you when a smaller fix will do.
Can I get a firm price before work starts?
Yes. The written plan names the where, the length of wall or drain, the pump and the price. A price set before the work starts is the price, and anything outside the written scope is agreed in writing first. Interior basement waterproofing
