Common approaches
| Approach | Typical use | Pricing basis |
|---|---|---|
| Interior coating | Limited vapor and surface dampness | Wall area |
| Crack repair | Specific non-moving wall defects | Per crack or linear length |
| Interior perimeter drainage | Recurring wall-floor seepage or groundwater | Basement perimeter |
| Sump pump | Collect and discharge drainage water | System and discharge conditions |
| Exterior membrane and drain | Manage water outside the foundation | Accessible exterior perimeter and depth |
Why exterior work costs more
Exterior systems may require excavation to footing depth, safe soil support, landscape or pavement removal, wall cleaning and repair, membrane, drainage board, footing drain work, backfill, compaction, and restoration. Access and depth are often more important than wall coating price.
Factors that change the estimate
- Basement perimeter and wall height
- Water source, severity, and frequency
- Exterior equipment access and restoration
- Number and condition of cracks
- Pump capacity, backup, and discharge routing
- Electrical work and permits
- Mold, damaged finishes, or structural repair
Low-cost checks before major work
Inspect gutters, downspouts, grading, window wells, plumbing leaks, exterior penetrations, and sump discharge. Direct roof water away from the foundation and correct obvious drainage defects. These steps do not replace a needed system, but they can remove avoidable water load.
Comparing proposals
Ask each contractor to identify the water source, define the system limits, show discharge routing, describe restoration, list exclusions, and explain the warranty. Compare the same perimeter and components.