Basement vent leak repair in Potomac, MD. Water was entering this home at a low exterior vent beneath a basement window. The repair addressed that specific opening—not every possible source of water around the house. The homeowner later identified a separate runoff issue, which requires its own drainage work.

Where was the water getting in?

The opening sat low on a brick foundation, close to the surrounding soil. Water reaching this area could pass through the unsealed vent perimeter. The project photos show the exposed opening and the small area of masonry that needed a targeted repair.

How did we seal the vent?

The completed job scope called for a bentonite-based waterstop around the vent, followed by a cement-based concrete cap approximately 10 by 6 inches. The crew cleaned the work area and checked the seal. The photos document the opening and visible exterior finish; the waterstop beneath the cap is not exposed in the finished view.

Did the vent repair solve the whole water problem?

The owner confirmed that the vent-related water entry was resolved. A later water concern came from a separate runoff path; that drainage work has not yet been completed. That distinction matters: sealing one penetration does not redirect runoff from another part of the property.

What should a homeowner check when water appears near a basement vent?

Look for the exact entry point during rain, the height of the vent relative to the soil, and whether water is collecting or flowing toward that wall. A vent-perimeter seal can be appropriate for a localized opening. If water is also moving across the yard or from a downspout, the drainage path needs a separate diagnosis and solution.

If you have a basement leak in Potomac or elsewhere in Montgomery County, request an inspection so the water source and repair scope can be identified before work begins.