Planning ranges
| Item | Planning range | Notes |
|---|---|---|
| Downspout extensions and regrading | $150 – $1,500 | Often the first and cheapest fix |
| Window well drain and cover | $250 – $800 | Per well |
| Interior drain system | $40 – $100 per foot | Cut floor, pipe, stone, membrane, new concrete |
| Sump pit and pump, new | $1,200 – $2,500 | Includes the discharge line |
| Battery backup pump | $700 – $1,500 | Added to an existing pit |
| Exterior excavation and membrane | $100 – $300 per foot | Dig to the footing, coat, board, drain, backfill |
How to read a waterproofing quote
Ask how many feet of wall are included, whether the price includes the sump pump and its discharge line, what happens to the old floor concrete, and whether the new concrete is finished smooth. Ask what the warranty covers and whether it transfers when you sell.
Where the money is best spent
If water comes in along one wall only after big storms, start with gutters, downspouts and grade on that side. If the cove joint is wet around most of the basement every spring, an interior drain will usually do more than any amount of outdoor work. The inspection tells you which picture you have.
Quick answers
Is exterior waterproofing worth the higher price?
When the yard is open and only one or two walls leak, it can be. For a whole basement, interior drainage is usually the better value.
Does waterproofing raise home value?
A dry basement with paperwork helps a sale. Buyers' inspectors look hard at water stains.
Will I need a permit?
Some cities and the county require one for excavation or certain interior work. We check for your address.
