Basement waterproofing in Scarsdale and nearby towns

Start with a diagnosis

A contractor worth hiring looks before selling. They should walk the outside of the house to check gutters, downspouts, grading, window wells and any low spots where water pools. Inside, they look at where the stains, puddles or efflorescence show up, check the cove joint and cracks, look at the sump pit if there is one and ask when the water appears. A basement that gets wet only after days of rain behaves differently from one that gets wet whenever the gutters overflow.

Write down what you have noticed before the visit: which walls, which storms, how much water and how fast it disappears. Photos from the last time it happened are useful.

The main fixes, from smallest to largest

Most contractors work through a short list, and many basements need only the first one or two.

• Fix gutters, extend downspouts and regrade soil so water runs away
• Seal cracks and pipe penetrations with injection
• Install or replace a sump pump, with a battery backup
• Cut an interior perimeter drain that feeds the sump
• Excavate outside and apply a membrane with a footing drain

Poured, block and stone foundations

Poured concrete walls usually leak at cracks and at the cove joint. Concrete block walls have hollow cores that fill with water and can let it out through mortar joints or weep along the bottom course. Stone foundations, found in some older Westchester homes, have many mortar joints and tend to let water through in many small places. Each type points to a different repair. Block walls, for instance, are often drained through small holes drilled into the bottom course as part of an interior drain system.

What a good proposal includes

A clear proposal lists the work by wall and by linear foot, the type of pump and pipe, where the discharge line goes, whether the floor will be patched and how, who pulls permits, what cleanup is included and the warranty terms. Compare at least two proposals if the job is large, and be wary of anyone who pushes the most expensive system without explaining why the smaller fixes will not work.

Living with a dry basement

Even after the leaks stop, basements stay cooler and more humid than the rest of the house. A dehumidifier set to about 50 percent humidity, draining to the sump or a floor drain, keeps mold and musty smells away. Keep stored items on shelves rather than the floor, and check the sump pump each spring and fall by pouring a bucket of water into the pit to make sure it starts.

Typical basement waterproofing costs

National figures from Fixr. Not quotes.

National figures, rounded, not quotes. Your price depends on the method, wall length, access and site conditions.

Sources: Fixr, basement waterproofing