Basement Waterproofing in Financial District, Manhattan

Why Do Financial District Basements Get Wet?

Much of the area is low lying, especially on the East River side and at the southern tip. Hurricane Sandy flooded Water Street, the Seaport and many building basements. Old walls, failed vault lights and cracked sidewalk flags let water reach cellars on blocks that were never flooded by storms.

Rising groundwater is one cause. Rain that runs off a crowded street and finds a gap is another. A cellar below a sidewalk vault gets water from above whenever a vault light or its joints fail.

Many cellars here are lined with old brick, stone or rubble. These materials absorb water, and mortar softens with time. Dampness often shows as white powder, peeling paint or a musty smell.

We cannot tell you whether your block is in a flood zone, and we do not guess. The city publishes flood information, and you should check your address there.

What Limits and Rules Apply to Cellar Waterproofing?

Sewer backups need a licensed plumber and a backwater valve, which we do not install ourselves. Structural problems may need an engineer, and structural work can need DOB permits. Sidewalk work needs a DOT permit. Confirm current rules with the city.

Our part is the masonry, concrete and sealing work: repointing walls, repairing slabs, sealing joints and fixing the sidewalk or vault surface that sends water below. Where a plumber or engineer is needed, we say so at the visit.

Historic district rules can apply too. Stone Street, the Fraunces Tavern Block and the South Street Seaport are historic districts. Most waterproofing happens inside, but exterior or sidewalk changes there may need Landmarks review.

Can paint or sealer fix a wet wall?

Usually not by itself. A coating on a wall with a live water source tends to peel. Fix the source first, then treat the wall.

Is the sidewalk part of the water problem?

It can be. Cracked flags and failed vault lights above a cellar feed water straight in. Sidewalk repair is part of what we do, and we can fix that and the cellar together.