Basement waterproofing techniques. Waterproofing basement in USA

US waterproofing basement is featured in “This Old House”

US Waterproofing is proud to have had their work featured in the March/April 1997 edition of THIS OLD HOUSEĀ® Magazine. The following text and photos are from that article.

US waterproofing basement Old House


Inside Job…
Wet basement headaches can be cured, with a little common sense and willingness to dip deep.

If she tries very hard, Pinky Markey of Greenwich, Connecticut, can think back to a time when her basement made her happy. Her husband, Terry, set up a workshop and an exercise room down there. Her two children all but disappeared into the playroom, which the previous owners–“nice people who swore it never leaked,” recalls Markey–had paneled in walnut. But soon after moving in 10 years ago, she walked downstairs barefoot after a spring rain and stepped onto a cold, soggy carpet.

It was just a little water at first, but with each storm the tide rose steadily higher in the basement, The Markeys installed an electric sump pump, which kept things relatively dry until last October, when a Nor’easter struck the coast. At six inches, the rains were bad, and the winds were powerful enough to topple a giant white oak on the family’s front lawn. When the tree fell, it ripped apart power lines across the street, leaving the Markeys–and their sump pump–without power for five days. Downstairs, water hit the two-foot mark. “Everything was floating,” Markey says. “All the kids’ toys were wiped out. The pool table–slate, or course–was hot. The exercise equipment, gone.” Not to mention the furnace and the water heater. In all, the damage came to $35,000. Worse, the Markeys’ insurance agent told them none of it would be covered, because their basement, like most basements in this country, was not covered for floods. “I always wondered why people totally freaked when it came to water in their basements,” Markey says. “Now I know.”

Among homeowners, few things can match the aggravation caused by a wet basement. And there’s no comfort in company: According to the American Society of Home Inspectors, 60 percent of all houses in the nation have foundation leaks, and the number climbs to 90 percent for houses built with cinderblocks. Water is a home’s greatest enemy. Accumulating in the basement even in tiny amounts, it can warp floorboards, rust the life out of appliances and utilities and turn finished rooms into mildewy caves. Just as bad is the cost, in time and money, of trying to find the leaks and fix them. Water seepage “is like cancer of the house,” says Tom Maiorano, president of U.S. Basement Waterproofing, a business he runs in Pleasantville, New York, with his sons Dean and Ron. “It shows up in one little spot, and before you know it, you’ve got a big problem.”

Even crawl spaces and poured slab foundations are susceptible to water damage. If drained improperly, they can trap moisture and leak. Hidden from view, the problem is easy to ignore until it’s too late. John Annunziata, a licensed home inspector in Westchester County, near New York City, slid around one wet crawl space recently only to discover that “you could grab the beams with your hand and squeeze them like a sponge because they had deteriorated.”

As frustrating as basement and crawl-space leaks are, many can be fixed with minor effort. “In a lot of cases, the problems occur because the site isn’t right,” says This Old House master carpenter Norm Abram. This condition can be corrected, he says, “by helping the natural drainage away from the foundation.” As a test, This Old House contractor Tom Silva suggests putting a ball on the ground next to the foundation. If it rolls away from the house, the slope is fine. “If it rolls toward the foundation, you’re in trouble,” he says. To fix the problem, Tom suggests clearing away plantings and gently building up the soil to slope away from the foundation, with a grade of at least one inch per four feet. (To protect against rot and insects, however, the soil should be kept at least eight inches away from wood siding.)

Downspouts can also be a source of trouble. Some end right at the foundation, where, during rainstorms, pools of runoff water can seep through cracks in the walls. Simply rerouting the water by extending the downspout a few feet away from the house can help. For bigger problems, the downspouts can be connected to a pipe buried 18 inches deep that uses gravity to drain water farther away from the foundation. But not every problem has such an easy fix. At certain times of the year, the rising water table can force itself into basements through a phenomenon known as hydrostatic pressure, which nothing can stop. “I’ve seen it actually squirting up through basement floors and into the air,” Tom says. In these cases, no amount of patching, regrading or drainage pipe will help. “You’ve got to find where the water’s coming from and get it out of there.”

During the same Nor’easter that deluged Pinky Markey’s basement, her neighbor Betty McMoran found her own basement filling with water for the first time since the house was built in 1956. It was hardly a deluge: A carpet-cleaning company sucked up just five gallons of water. But McMoran depends on rent from a tenant in her basement apartment–a tenant she was likely to lose if the flooding continued. “When I saw that water, I knew it was only going to get worse,” she says.

During inspection, Tom Maiorano quickly found the problem: McMoran’s house had been built into a rocky hillside, and runoff water drained directly against the front foundation wall. To complicate things, a puddle of water near the front door turned out to be a spring, which kept the ground saturated year-round. “The miracle is that this was her first leak,” he says.

When regrading is not the answer, Maiorano suggests building either an interior or an exterior perimeter drain to stop leakage. McMoran chose the exterior system, because she didn’t want to rip up the carpet and floors in her finished basement. “I wanted the mess outside,” she says. First, work crews excavated around the front of the house down to the footings. They laid a drainage pipe in gravel to draw water away to a deep runoff trench dug to one side of the yard. As a precaution, the foundation walls were waterproofed not just with a 60-mil coating of tar, but with a 22-mil rubberized sheet and an inch of foam insulation as well. “It’s a lot of material, ” Maiorano says, “but there’s no other way to make sure it works.” Finished in three days, the new drains and the waterproofing cost McMoran $7,590, but the expense seemed worth it when the next storm arrived. “It rained last night, and guess what–no water!” she says with delight. “I ran down about eight times to check.”

McMoran may now be free of water worries, but her friend Pinky Markey still finds herself mired. In the weeks since the Nor’easter, she has had some good news. The insurance company finally declared her basement disaster “an act of God” and covered everything. But to prevent another flood, the Markeys must build an exterior perimeter drain around their entire house. The estimated cost, which will not be covered by insurance, is “25,000. Not surprisingly, Markey lately finds herself yearning for a basement-free life. “I want to do the Henry David Thoreau thing,” she says. “Give me some woods, and give me a cabin. We humans can survive in the simplest of environments, as long as it’s warm.” And dry.
Betty McMoran loved the way her house tucked into a Connecticuts hillside–until the foundation started absorbing runoff water.

Careful to avoid smashing the stone facade or ripping into lines for water and natural gas, waterproofing expert Dean Maiorano maneuvers an excavator across the front of McMoran’s house and digs a trough down to the footings.

In order to drain all the water that might leak inside the house, the exterior perimeter drain must be placed next to the footings, below the basement floor. To reach this level, workers jackhammer a trench through 6 inches of ledge rock that couldn’t be budged with the excavator.

Instead of using foundation tar, a worker seals the exposed wall by quickly smearing on a layer of 60-mil-thick fibered cement, similar to roofing cement.

The foundation coating makes the walls damp-proof, not waterproof. For extra protection, the crew affixes a 22-mil-thick plastic rubberized sheet that stops water from penetrating unseen cracks.
After a corrugated black drainpipe is laid in the trough, gravel is spread on top to keep the pipe from plugging up with dirt. On the walls, sheets of 1-inch foam insulation are glued onto the rubberized sheet to prevent tearing.

After the trench is backfilled to the halfway point, a second drainpipe is installed to catch runoff from the downspouts.

Both the footing drain and the downspout drain are fed by gravity into pipes buried in a trench dug off to the side of the house.

Inside Job…

During a rainstorm at their new house in Brewster, New York, David Angley and his family found their downstairs rec room filling with water. “There was nothing we could do but stack up the furniture, roll up the carpets and start pumping it out,” he says. An inspection revealed the problem: The house’s exterior footing drains had been damaged during construction. The could be replaced, but a cheaper solution lay indoors: running a drainpipe along the basement wall. For $4,000, a crew jackhammered a trench into the basement floor, top left, then dug it out so four-inch corrugated piping with slits on all sides would lie below the concrete slab, middle. Interior systems require a gravity feed or a sump pump, which is installed in a shallow well, bottom left. Once the pipe is placed in the trench and covered with gravel, below, a plastic vapor barrier, bottom right, is laid on tip and then patched with cement. “We’ve had lots of rain since,” Angley says, “but it’s been dry as a bone.”

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