Basement Waterproofing Cost Calculator
Price a basement waterproofing job from the wall perimeter and the price per linear foot in your own quote — whichever method you choose — plus an optional sump add-on.
Calculator
Waterproofing a 120 LF perimeter at $75.00/ft is about $9,000.00 with your sump add-on. Enter the $/ft for the method you pick (interior drain tile, exterior membrane or sealant) from your own quote.
Basement waterproofing is usually priced by the linear foot of wall the system follows, so the math is simple once you know two numbers: how many feet of wall you are treating and the price per foot from your contractor’s quote. This calculator keeps those two figures in your hands — enter the perimeter you measured and the $/ft you were quoted, add the installed sump price if the method needs one, and it returns a clean planning total.
The right $/ft depends on the method. There are three broad families, and each is the honest answer to a different problem — enter the $/ft for the one you are actually pricing:
Formula
total = perimeter × price_per_ft + sump
Perimeter is the linear feet of wall the system runs along; price_per_ft is the installed $/ft from your quote for the method you chose; sump is the optional installed sump pump / pit. No price is baked in — the number is only as good as the $/ft you enter.
Worked example
Say you are waterproofing a 120 linear foot perimeter and your interior drain-tile quote works out to $75 per foot, with a $1,200 sump pump installed:
120 × $75 = $9,000, then + $1,200 sump = $10,200.
So the planning total is about $10,200. Change the method — an exterior excavation-and-membrane job carries a much higher $/ft than an interior sealant — and the total moves with the $/ft you type, not with any figure we store.
Interior vs exterior vs sealant
Interior drain tile + sump collects water that reaches the footing and pumps it out; it is priced per linear foot of interior footing and pairs with a sump. Exterior excavation + membrane digs down to the footing and waterproofs the wall from outside — the most involved and highest $/ft, and heavy excavation that needs licensed pros and a permit. Interior sealant / coating is the lightest option and resists damp, but it is not a fix for active water under pressure. For a side-by-side of the methods, see the reference table below and the waterproofing methods table. Persistent water, movement or cracking is a signal to have a licensed structural or geotechnical engineer look before you commit to a method.
Reference table
| Method | What it is |
|---|---|
| Interior drain tile + sump | Perforated pipe in the footing trench routes water to a sump; priced per linear foot of interior footing. |
| Exterior excavation + membrane | Excavate to the footing and waterproof the wall from outside; highest $/ft, heavy excavation, permit needed. |
| Interior sealant / coating | Interior masonry coating that resists damp; lightest option, not a fix for active water pressure. |
Methods only — enter the $/ft from your own quote. No prices are stored here.