Waterproofing checklists

Before you call anyone. Log dates and weather when water appears. Photograph every wet area with a date. Do the plastic-sheet condensation test. Read your humidity with a meter (EPA target: below 60 percent, ideally 30-50). Clean gutters, extend downspouts, and check that ground falls at least 6 inches in the first 10 feet (2021 IRC R401.3). Note anything outside that would block excavation: deck, driveway, AC unit, mature trees.

Comparing quotes. Every bid should state: the diagnosed water source; the method; linear feet covered; pipe type, diameter and filter fabric; stone type; pump make, model and horsepower; battery backup yes or no; discharge line length and destination; excavation depth; what is removed and what is restored; who pulls the permit; start date and duration; payment schedule; and the full written warranty, including what voids it and whether it transfers.

Before final payment. Run water into the system and watch the pump cycle. Confirm the discharge point is where the contract said. Check that concrete patching is finished and level. Confirm any removed landscaping, decking or driveway is restored as promised. Collect the permit sign-off if one was pulled, the warranty document, and product data sheets for the pump and membrane.

Every year after. Test the pump by pouring water into the pit. Clean the pit of gravel and silt. Check the check valve and the discharge line for ice or blockage. Confirm the battery backup still holds charge. Re-check grading after settling, and clean gutters twice a year.

How to choose

Do the condensation test before spending anything

Two days and a piece of plastic can save you from buying a drainage system for a dehumidifier problem.

Force bids onto identical line items

Send all three contractors the same list of items to price. Otherwise you are comparing numbers that describe different work.

Hold back a final payment until you have inspected

A meaningful retainage tied to a walkthrough is normal and reasonable to ask for.

Get the warranty before, not after

Read the full warranty document during the quote stage. Warranty terms are set by each individual company and vary widely — never assume.

Diary the annual pump test

A sump pump that has never been tested is the most common single point of failure in an interior system.