Many cellars suddenly turned to pools during the deluges of last spring. Here's how to protect yourself against the next downpour.

By A. I. Schultzer, Senior Editor

(Article from Medical Economics Magazine/November 14, 1983)

The young Connecticut gynecologist's first clue that there was water in his cellar was the sight of his favorite wood tennis racquet and a trail of tennis balls floating past the foot of the steps after a night of heavy rain. His frantic attempts to dry up the flood only resulted in a backache.

"My wife and I knocked ourselves out all weekend," the OBG lamented, "dragging pail after pail of water out of the basement."

A more experienced M.D. homeowner explained: The OBG had been trying to lower the water table around his house. "For every pailful you and your wife took out, another rushed in," the older man said. "You'll have water in your cellar until we get a dry spell and the water table drops of its own accord." Then he recommended that the OBG see about waterproofing his cellar.

That recommendation is common. In this especially wet year, many physicians have discovered miniature tidal basins seeping up through their cellar floors. It's a problem that can be solved, although not always simply or cheaply. Here's what causes a flooded basement and what can be done to waterproof it.

Where basement water comes from.
"Two kinds of water get into a basement, surface and ground," says Louis Alloro of Bonded Waterproofing Systems Co., Bergenfield, N.J., a veteran of over 20 years of putting his finger in the basement dike. Surface water is runoff water, usually the result of a heavy storm in combination with blocked gutters or downspouts. "Surface water will show up as stains starting at the top of a cellar wall," says Alloro. "If there's enough water, it'll come all the way down to the floor."

Groundwater comes from below as the water table builds up on top of the subsurface rock, shale, or other impermeable layer under your house. That explains why a higher elevation doesn't always guarantee a dry cellar in a wet year.

"For signs that the groundwater may be the problem in a wet season, look at the floor," says Alloro. "Sometimes you get rust stains near the heating equipment or the Lally columns--the weight-supporting pipes--in a house. Also check the wall where it meets the floor for a white powder. That's efflorescence, lime that's been leached out of the cinder or concrete blocks by water seeping into the cellar."

Eliminating surface water. This job is a matter of seeing where water collects and then doing something about it. The best time to locate trouble spots is during a rainstorm. Then take these steps.

• Keep gutters and downspouts well-maintained and clear of leaves and other debris. Otherwise they'll dump hundreds of gallons of water around the house foundation instead of carrying it away. Eventually that water will find its way into the cellar.
  
  
• Make sure the subsurface drain tile or pipes into which downspouts discharge aren't clogged by debris. They are if they back up in a storm. You can clear them with chemicals available in most hardware stores. If your home doesn't have subsurface drains, install concrete splash blocks where downspouts discharge, and pitch them to direct runoff at least 6 feet away from the house foundation.
  
  
• Protect basement window wells. If landscaping near the house is pitched toward the foundation, for example, water will flow into the wells. In even a moderate storm, water will build up rapidly and will seep through window joints or the wall into the cellar. To cure this, grade the landscaping away from the house and build up the height of the window-well perimeter with corrugated sheet metal. If that doesn't work, you may have to install underground drainage pipes.

Correcting groundwater problems.
Waterproofing contractors generally deride attempts to waterproof a basement wall from the outside after a house is built. If you coat foundation walls with tar or polyethylene film, constant exposure to the earth will sooner or later break the seal, and hydrostatic pressure will force water through the foundation wall.

"If you coat the inside of the wall with a waterproof sealant," says Alloro, "you'll trap water inside the foundation wall, where it'll do more damage than if it had passed through into the cellar."

That's what not to do. Here's what you should do.

• Use a sump pump in a cellar floor to lower the water table. "If there's excellent natural drainage under the cellar floor--if, for example, the cellar floor was laid on a bed of gravel--a sump pump can keep the cellar dry," says Alloro.
  
  A sump pump is installed in a plastic- or concrete-lined pit dug about 36 inches deep in the basement floor, where water first collects. It pumps the water that accumulates in the pit to a storm sewer, dry well, or brook well away from the house.
  
  The pump may be either of two kinds: submersible, which is immersed in the water, or pedestal, in which the pump motor sits on top of a shaft with a submerged impeller. In either case, a float triggers a switch that turns on the electric pump. When the level of the water in the sump drops, the pump switches off.
  
  
• A French drain can be used with a sump pump if the pump itself doesn't get rid of cellar water. To construct a French drain, you have to break through the cellar floor and dig a trench around its perimeter about 12 inches wide and up to 12 inches deep. The trench must reach to the bottom of the concrete footing of the foundation wall.
  
  "We then bleed the cellar wall," says Alloro. "That means tapping holes in each cinder block around the wall, so that water can drain through it into the ditch." A perforated 4-inch drainpipe is then laid in the French drain and covered with gravel. From this perimeter drain, a feeder drain is dug to the sump pump so water that collects can be pumped out of the cellar. To restore your cellar floor, the French drain is covered with cement--except for a three-quarter-inch-wide track next to the cellar wall. This is a fail-safe opening to catch water that may seep through the joint where wall and floor meet.

Waterproofing Caption 1: Workers use jackhammer to break up the finished basement floor and dig a French drain 1-foot wide around the cellar perimeter and down to the foundation base. The prefabricated sump tub, discharge pipe, and sump pump will be placed in a pit dug in the floor. Drains are pitched from the drain to the sump.

Waterproofing Caption 2: A discharge pipe rises from the sump and exits through the cellar wall to the outside. Gravel is laid in the drain before capping it with concrete.