By Al Warson
There doesn't appear to
be any compelling reason, short of a hurricane or flood, why water should leak
into basements in single-family homes, townhouses, stacked or otherwise, or
apartment buildings. Nor is there any reason enough moisture should accumulate
to create that unpleasantly pungent, lingering dampness odour - not with two
popular Canadian foundation waterproofing products sold across North America.
One of them is manufactured by Guelph, Ontario-based ArmTec, the other by Cosella Dorken Products Inc. of Beamsville, Ontario. Both systems are based on an air-gap membrane principle, not unlike the air barrier cavity systems in office buildings, which are designed to prevent hard-driving rain from leaking inside through badly caulked windows.
Ken Macdougall, ArmTec's Ontario sales manager, explains that his company's Platon Foundation Protector, a high-density polyethylene (including some recycled product) membrane, is wrapped around the basement exterior walls before the excavation is filled in. That can be concrete block walls, poured concrete walls, permanent wood (PWF), insulated concrete forms and existing, as opposed to new, foundations.
"The air membrane keeps water away from the basement walls and allows it to flow into the foundation drain and then into tubing [which his company also manufactures], drawing it farther away," he says. There is a top piece to the system that is fixed to just below grade to hold it in place, and "dimples" that keep the membrane rigidly away from the wall.
Wet soil can't push the membrane up against the wall, Macdougall says, which allows water to eventually escape into a sump pump - providing there are no cracks in the basement wall to which water will naturally gravitate. Water not only seeks its own level, but any crack in a wall through which it can flow.
Macdougall says condensation on the back of the membrane also dries out the foundation. Moreover, the basement wall can shift, crack and settle without affecting the product's performance. There is also a basement flooring application, he says, because the membrane can act as a sub-floor, keeping moisture out and helping to keep the basement warm. Anyone who has spent any time in a damp, cool or even cold basement will appreciate what he's saying.
Macdougall, who points
out that ArmTec isn't an installer, figures that the Platon system would add
about $600 to the cost of a 1,000-square-foot house. This is less costly than
repairing a water damaged basement and avoids a jump in the insurance premium
if, in fact, the homeowners' policy covers water damage.
Dave Gallagher, Cosella Dorken Product's controller, says his company's DELTA®-MS high-density polyethylene resin product is "impermeable to water and water vapour and unaffected by ground soil acidic or alkaline environments," stabilized against oxidation, and impact-, chemical- and environmental-stress crack resistant. He says their product is the only dimpled membrane on the market manufactured in a co-extrusion process, using virgin polyethylene on the outside layers and post-industrial recycled high-density polyethylene in the middle. The membrane comes in a chocolate brown and orange stripe pattern - before it disappears forever underground.
Before it does disappear, during back-fill operations, the membrane protects the walls from damage. DELTA®-MS, Gallagher says, bridges large cracks, ignores damage points and deflects water as well as soil dampness. The company's literature notes that the "membrane is vacuum formed in a dimpled pattern to create an air-gap at the foundation wall. This unique design allows any water getting past the dimpled membrane to fall freely to the footer drain."
Gallagher says that, while the concept is very simple, the manufacturing process involves high technology that facilitates a level of production, which serves a large and growing market. The firm's business is mainly in Ontario and with single-family home builders - not that it excludes "anything with a foundation," he says, but customers in western and eastern Canada are also becoming familiar with it, and Quebec is turning into a growing market. Gallagher says his company is also looking at the flooring application. DELTA®-MS was imported from the parent company in Germany from 1992 until 1995 when the Canadian operation was established.
In terms of what the system would add to the cost of a house, Gallagher ventured somewhere between $400 to $800, depending on the size of the house. On the other hand, he says, it is worth the additional cost to avoid bad relations (and a damaged reputation) with a homeowner over water in their basement and going back to repair the damage at a cost of thousands of dollars to make sure it doesn't happen again. HB
Pictures courtesy of Cosella Dorken Products Inc. (top) and ArmTec