Foundation Waterproofing Cost: Exterior Membrane, Coating, and Drain

What this page prices, and what it does not

Foundation waterproofing cost means the outside job. Excavating to the footing, parging the wall, then coating or membrane on the exterior face. Then a drainage mat, the footing drain, and backfill. New construction and crawlspaces count too.

Interior systems are different money. The sump pump, the interior sealer, and the digging it takes live on our basement waterproofing cost page.

SimplyWise Cost Estimator turns a photo into an itemized estimate in about 6 seconds.

Dampproofing and waterproofing are two different code jobs

Most cost pages skip this. It moves the material line more than anything.

Section R406.1 of the model code calls for dampproofing on walls that retain earth and enclose space below grade. It runs from grade to the top of the footing, or 6 inches below the basement floor, whichever is higher. Masonry gets 3/8 inch of portland cement parging first, then one of five listed coatings, bituminous among them.

Section R406.2 calls for waterproofing instead, where a high water table or severe soil water conditions are known. Its list is two ply hot mopped felts, 55 pound roll roofing, and 40 mil polymer modified asphalt. Also 60 mil flexible polymer cement, a 1/8 inch fiber reinforced cement coating, and 60 mil liquid rubber.

What the exterior materials cost

Three lines carry the job, and the sheet membrane also needs its primer, which is not priced here. Every figure came off a seller or a maker.

A 140 foot wall treated 8 feet high is 1,120 sq ft. Membrane alone is 6 rolls, $924 to $1,101. With the mat, $1,960 to $2,516. Coating is 5 to 7 pails, $289 to $441.

What we will not price

No publisher we accept states an installed price a foot, so none is printed here. Fluid applied coatings were looked at and dropped, because the maker coverage spreads are too wide to turn a pail into a rate.

The footing drain the code asks for

Section R405.1 wants drains around foundations enclosing usable space below grade. The dimensions take off cleanly.

Stone drains run 1 foot past the outside edge of the footing, and 6 inches above its top. A filter membrane covers them. Perforated pipe sits on 2 inches of washed rock and gets 6 inches over it. Group I soils, the well drained gravels and sands, are exempt.

What the labor side pays

Construction Laborers posted a May 2025 national median of $22.66 an hour and a mean of $25.02. The 25th percentile sits at $18.57 and the 90th at $37.54.

The excavator seat pays more. Operating Engineers posted a median of $28.78 and a 90th of $48.60. Both are wages, not what you bill. The survey skips the self employed, and your rate carries burden, machine, and margin.

Price an exterior foundation job in four steps

1. Measure the run and the treated height

   Tape the run and the height from grade to the footing top, then multiply.

2. Settle dampproofing against waterproofing

   Read R406.1 and R406.2 against the local amendment and the soil report.

3. Count rolls and pails, and round up

   Sheet and mat run 200 sq ft a roll before laps. A pail covers 350 to 500 sq ft a coat.

4. Add the drain, the stone, and your hours

   Take pipe and rock off the R405.1 dimensions, then price hours off your own sheet.