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Basement Wall Waterproofing Coating Coverage Calculator

Calculate the waterproofing coating needed for a basement wall based on coverage rate and number of coats.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-27 · v1.1.0

Market
Imperial · sales tax

Waterproofing coating needed

5.28 gal

Check your inputs

A coating on a basement wall is one part of a system whose other parts — drainage, a drainage board, and somewhere for water to go — do most of the work. Applied alone against real hydrostatic pressure, a coating is being asked to do something it cannot.

With the figures above, the waterproofing coating needed comes to 20 L. The method behind this is well established, though site conditions and material batches will move it somewhat. This is calculated for United States and cites IRC 2024. Building in another market? Change the selector above so the units and code reference follow.

Estimated cost — your price

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Material needed = (area ÷ coverage rate per coat) × number of coats, the standard multi-coat coverage method

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Frequently asked questions

Will a coating alone keep a basement dry?
Not against standing water. A coating resists moisture passing through the wall; it does not resist a head of water pressing against it, and the pressure a saturated soil can generate is substantial. The coating is the last line — the drainage that keeps water from building up against the wall in the first place is what actually keeps the basement dry.
What is the difference between positive and negative side?
Which face the water is on. A positive-side coating is applied to the outside, where water arrives, and is pressed against the wall by the water. A negative-side coating is applied inside and is being pushed off the wall. They are different products with different adhesion and permeability requirements, and using one where the other belongs is a common and expensive substitution.
Why did my coating blister off?
Usually moisture behind it, or a substrate that was not prepared. A negative-side coating applied over a wall that is still passing water will be lifted off by that water; a coating applied over dust, laitance or a curing compound never bonded in the first place. Preparation is a larger share of the labour than the application.
Where does the water actually go?
That is the question that decides whether the system works. A perimeter drain must discharge somewhere — to daylight, to a storm connection, or to a sump with a pump — and a drain that discharges nowhere is a reservoir against the footing. Any waterproofing scheme that does not answer this question is incomplete regardless of what is on the wall.