Nor'easter and hurricane prep for city homes and buildings

Why city storms flood from both directions

Heavy rain overwhelms the sewers: on September 1, 2021, Ida put 3.15 inches of rain on Central Park in one hour (source), and much of the city drains rain and sewage through the same pipes (source). Water comes up through basement drains while wind-driven rain comes in through roofs and windows above.

Coastal storms add surge: Sandy's water reached deep into Lower Manhattan and the West Village (source).

Roofs, drains and gutters

Flat city roofs drain through a few roof drains and scuppers. If leaves or debris block them, water ponds and finds every weak seam. Clear roof drains, scuppers and gutters before the storm, and check that downspouts aren't disconnected at the bottom.

Look at flashing around bulkheads, skylights and chimneys; that's where most top-floor leaks start.

Windows, doors and air conditioners

Wind-driven rain gets past window seals, through gaps around window air conditioners and under ground-floor doors. Close and latch windows, pull or seal around window units if you can, and keep towels ready at doors that face the wind.

Bring in anything loose on balconies, terraces and fire escapes; it becomes debris in a strong wind.

Basements and floor drains

Move belongings off basement floors, especially anything stored in cardboard. If the building has a backwater valve, make sure it's clear; if it doesn't and backups have happened before, ask a plumber about one (source). Our guide on sewer backups explains why basements back up in cloudbursts.

In apartment buildings

Supers should check roof drains, areaway drains, sump pumps and the boiler room before the storm and know where the main water and power shutoffs are. Residents on top floors and ground floors are the most exposed; ask them to report leaks quickly so the building can act before water spreads.

Records before the storm

Take photos of your rooms and belongings before storm season. It takes ten minutes with a phone and makes any claim easier. Keep your policy number, your insurer's claims line and the building's emergency contacts somewhere you can reach without power.

Ground-floor stores and restaurants

Businesses on the ground floor take water from the street and from backups in the building's line. Move stock off the floor, protect electrical equipment and know where the building's shutoffs are. Our commercial restoration page covers how we dry and clean a business in stages so it can reopen sooner.

Power outages and pumps

Storms often cut power, and a sump pump without backup power stops when it's needed most. Buildings with pumps in basements or elevator pits should check backup power before storm season. Residents should keep phones charged and flashlights handy rather than candles.

Top floors and roof leaks

Top-floor apartments are where wind-driven rain and roof leaks show up first, often as a stain along the wall or around a light. Report it right away; a leak that runs through a storm can soak insulation and ceilings across the whole floor. Our ceiling leak page explains the drying.

Cars, stoops and areaways

Street-level flooding reaches ground-floor doors, areaways and cars parked in low spots. Move cars to higher ground if flooding is forecast, clear areaway drains, and keep sandbags or door barriers ready if your entrance has flooded before.

After the water goes down, photograph the high-water mark on walls and doors before cleaning; it shows how deep the flooding was.

After the storm

Check ceilings, walls under windows and the basement once the rain stops, even if nothing looked wrong during the storm. Photograph any damage before cleaning up, cover openings to stop more water getting in, and call for extraction if water is standing. Our storm damage page explains the job.