Exterior Basement Waterproofing in Schenectady

• What's involved
• When it's worth it
• The case against
• Access decides it
• Cost
• Questions

What's involved

The wall is excavated from outside to the footing — seven or eight feet on a full cellar. Once exposed, it's cleaned, deteriorated mortar is cut out and repointed, spalled masonry is repaired, and the surface is parged smooth where it needs to be. Then a rubberized asphalt or elastomeric membrane seals it, and dimpled drainage board goes over the membrane to create an air gap so any water reaching the wall runs down rather than sitting against it.

At the base, a new footing drain is bedded in washed stone and wrapped in filter fabric, pitched to daylight where the lot falls away or to a sump where it doesn't. The trench is backfilled — ideally with free-draining material rather than the clay that came out — and the grade rebuilt to fall away from the house, roughly six inches over the first ten feet.

When it's worth the money

• The wall itself is deteriorating. Mortar washing out of a rubble wall, spalling block, water moving through the masonry. Interior drainage manages the symptom; this repairs the cause. On Schenectady's older stock this is the strongest argument for going outside.
• The basement is already finished. Demolishing a finished basement for an interior drain often costs more than digging outside once the rebuild is counted.
• You want dry walls, not just a dry floor. On old masonry, sealing from outside is the only route to that.
• The grade needs rebuilding anyway. If you're regrading, doing the wall while the trench is open costs far less than doing it later.
• You're already excavating. New egress window, sewer lateral replacement, an addition. Do it while the machine is on site.

The honest case against

It's disruptive in a way interior work isn't. The yard becomes a construction site: spoil pile, machine, open trench along the house. Foundation plantings in the excavation zone don't survive, and mostly don't go back. A patio, walk or driveway along that wall comes up and has to be replaced, which is a separate cost people routinely forget to budget.

It's weather-dependent. From roughly December through March, frozen ground makes excavation impractical here. That's a real scheduling constraint, and it's why we often stabilize things inside over winter and dig in spring.

And it isn't automatically better. Where water is plainly hydrostatic — rising through the slab and the cove joint on every wall — an interior system addresses it directly for a third of the cost. Sealing the outside does nothing about water pushing up from beneath the floor. Anyone presenting exterior as universally superior is selling rather than diagnosing.

Access decides this more than anything else

The single biggest variable is whether a machine can reach the wall, and in Schenectady the answer is often no. Stockade lots are narrow and tightly built. Central Park, Bellevue and the older streets off Union have side yards measured in single-digit feet. Hand-digging an eight-foot trench changes the economics completely — sometimes to the point where exterior work stops making sense at all.

Adding cost, in rough order of how often it comes up: a driveway or patio along the wall, a deck, gas and electric services entering that side, an AC condenser, mature trees with roots in the trench line, a property line closer than about twelve feet, and slope that makes machine positioning awkward. None is fatal alone. Several together point you back inside.

What it costs

Frequently excluded and worth asking about explicitly: replacing a patio or walk that has to come up, restoring landscaping, and masonry repair discovered once the wall is exposed. That last one is the usual surprise — nobody can see the bottom four feet of a foundation until it's dug up. A good contractor gives you a unit price for repointing up front so it isn't a negotiation mid-job.

Questions about exterior work