Foundation & Basement Waterproofing: what to know
Connecticut basements get wet for local reasons: heavy, poorly draining soils through the Connecticut River valley, a high seasonal water table, snowmelt on frozen ground that cannot absorb it, and frost pressure in saturated backfill pushing against the wall every winter.
Fix it in the right order
- Water delivery. Blocked gutters, a downspout discharging two feet from the wall, and grade sloping toward the house cause a startling share of "foundation leaks". This is the cheapest step and it is skipped constantly.
- Interior measures. Polyurethane or epoxy injection for a poured-wall crack; an interior perimeter drain to a sump for chronic seepage.
- Exterior work. Excavating the wall, repairing and membrane-waterproofing it, and installing a proper footing drain in stone with filter fabric. Thorough, effective, and by far the most expensive.
Stone foundations are different
Plenty of Connecticut homes sit on rubble stone or fieldstone laid in lime mortar, often with no real footing. Those walls were never designed to be waterproof: they were designed to breathe and drain. Coating the inside face with an impermeable sealer traps moisture in the wall and pushes the mortar apart. The right approach is normally repointing with a compatible lime-based mortar plus managing the water outside and under the slab.
When to call an engineer instead
A horizontal crack in a block wall, stair-stepping through mortar joints, a wall that has bowed inward, offset between two sides of a crack, or doors binding upstairs are structural signals. Those need a licensed professional engineer to specify the repair, with a mason executing that specification, not a waterproofing salesperson recommending a product.