Exterior Membrane on the Uphill Wall, Bedford

Reading the slope

Bedford runs downhill to the Basin, and on a sloped lot groundwater moves laterally through the soil following the grade. It arrives at the uphill wall of the house and has to go around, or through.

This property showed water on the west elevation only. The other three walls were dry through every season. That is worth stating plainly because it changes the price of the job by a large multiple: quoting a full-perimeter excavation here would have been selling three walls of work that would accomplish nothing.

What the excavation revealed

Once the wall was exposed, two things were visible that could not have been diagnosed from inside.

The original damp-proofing, the thin black asphalt coating sprayed on at construction, had failed across large areas. This is normal. Damp-proofing is a moisture retarder, not a waterproofing product; it is brittle, it cannot bridge a crack, and it takes physical damage during backfill.

The form-tie holes had never been properly sealed. These are the holes left by the steel ties that hold the forms together during a pour, and on a poured wall they run clean through the concrete. Unsealed, each one is a direct path.

What was done

The wall was cleaned back to sound concrete. Form-tie holes were cleaned and sealed, and minor cracking was repaired from the exterior face: work that is only possible with the wall exposed.

A true waterproofing membrane was applied over the full wall height and detailed at the wall-to-footing joint and at every corner. Dimpled drainage board went over it, creating a permanent air gap that carries any water down to the footing drain and protects the membrane during backfill.

New footing drainage in filter-wrapped washed stone was sloped to a daylight discharge: available here because of the same fall that caused the problem.

Free-draining backfill was placed in lifts and the final grade set to fall away from the house.

Result

The wall is dry, and the system has no pump and no power dependency.