Start with conditions, not a product
On Asheville's hillside lots, a wet basement wall can trace back to slope drainage, retaining-wall seepage, hydrostatic pressure, a settled crack, or condensation -- each with its own fix, not a shared one.
Build a complete scope
- Where the water enters, and from which direction on the slope
- The condition of any retaining wall holding ground above the foundation
- What is being corrected outside the wall, not only what is installed inside it
- The method proposed, and what was considered and ruled out
- Access on a steep lot, restoration afterward, and what the warranty covers
Asheville context
On a mountainside the physics are one-sided, and that is the thing to understand about below-grade water here. A wall cut into a slope has soil bearing against it to nearly full height on the uphill face and little or nothing on the downhill one, so pressure arrives from a single direction rather than evenly around the structure. Mountain clay makes it worse by holding water instead of draining it, so after the intense rainfall this region gets, that uphill face stays loaded for days. Freeze-thaw cycling then works the resulting cracks open a little further each winter, which is why leakage here is typically seasonal and progressive rather than constant. Almost all of that is decided outside the wall, which is where a durable fix usually has to happen.