Bentonite clay is the moving part. It swells when wet and shrinks when dry, and the shrink half of the cycle opens hairline cracks in foundations and floor joints. The next wet season, the same cracks are the entry points, and the swollen clay then holds the water against the wall for days. The signature is seasonal seepage at the same joints, worst after the ground saturates. The answers run outside in: drainage and grading that move water away, crack repair in the dry season, and a sump that is tested before the melt rather than during it.
Prefer to talk later? Leave your details and an independent local pro will call you back. No charge to you, no obligation.
Plum Creek Restoration is a free referral service. Submitting this form connects you with independent local contractors who provide the work.