Waterproofing services

Most companies sell one method because that is the method they own equipment for. An interior-drainage company will recommend interior drainage. An excavation company will recommend digging. Neither is lying, but neither is neutral. Get quotes from at least one of each before you sign anything over about $5,000.

The important distinction is managing water versus stopping water. An interior perimeter drain and sump pump does not keep water out of your foundation wall — it catches water that has already come through and pumps it away. That is often the right, affordable answer. But if you are finishing the basement or the wall is deteriorating, water still passing through the block is a problem you have not solved.

Before anyone sells you a system, the cheap stuff should be ruled out. Clogged gutters, a downspout dumping at the foundation, and soil sloping toward the house cause a large share of wet basements. The residential code baseline is ground that falls at least 6 inches within the first 10 feet from the wall (2021 IRC R401.3). Fixing grading and downspouts costs a fraction of a drainage system and sometimes ends the problem.

If you were sold at your kitchen table, note that the FTC's Cooling-Off Rule generally gives you until midnight of the third business day to cancel a sale of $25 or more made in your home — in writing, not by phone (FTC, 16 CFR Part 429). Exceptions exist, so read the FTC page.

How to choose

Start with a diagnosis, not a product

A good contractor asks when the water appears, where it enters, and what the outside of the house looks like. One who quotes a system before walking the exterior is selling, not diagnosing.

Interior drainage for chronic seepage

Best when water enters at the wall-floor joint after heavy rain and you mainly want a dry, usable space. Less disruptive and usually cheaper than excavation.

Exterior work when the wall itself is the problem

Worth the excavation cost if the wall is spalling, bowing, or you are protecting a finished basement long-term. It is the only approach that keeps water out of the foundation.

Crack injection for a single, identifiable leak

Epoxy or polyurethane injection into one poured-concrete crack runs roughly $300-$800 per crack (HomeCostLab). If a contractor quotes a whole-perimeter system for one crack, get another opinion.

Site work first, always

Gutters, downspout extensions and regrading are cheap and reversible. Do them and wait through one wet season before spending five figures, unless water is actively damaging the structure.