Perimeter waterproofing systems install on the inside of the home's foundation walls and underneath the basement floor. These drainage systems are much more accessible for maintenance purposes. Drain tile installation begins by jackhammering the foundation floor about 18-24 inches away from the interior wall. Alternatively, Basement Systems' best French drain, WaterGuard subfloor drainage system, will need only 8-12 inches of the concrete floor to be removed for the perimeter waterproofing system's installation. This is made possible because WaterGuard rests on top of the footer and directly against the basement wall.
After the perimeter drain has been installed, the soil underneath is excavated out from 8-18 inches deep. There are some contractors who believe a deep trench is the best choice, but the farther down the trench is dug, the more water that must be uselessly removed from around the foundation by the sump pump system and the sooner the sump pump will need maintenance. Areas with a high water table will not benefit by digging down to the water when it's not reaching the house. A deeper sump pump pit does not mean a drier basement, and it may even mean a housing code violation.
Once the trench has been dug, perforated PVC drainage pipe is installed in the bottom of the trench. This PVC pipe is sometimes equipped with a fabric filter sleeve that is designed to prevent silt, mud, or debris from clogging the pipe. Like any other filter, however, this material eventually clogs. And because the pipe and filter fabric is located deep underneath the concrete floor, it is not serviceable.
Drain tile is laid with a slight angle to allow it to drain into a sump pit. The sump pump then discharges the water from the basement, directing it away from the house. A reliable sump pump system is important - if you install one that fails and has no battery backup, your basement will flood. Basement Systems dealers have sump pumps, backup sump pumps, and battery backup sump pump systems that are the best in the world!
Bay Area Moisture Control has access to these patented and award-winning basement waterproofing products!
After a standard drain tile and sump pump have been installed in this foundation waterproofing system, the gap remaining in the trench can be filled with gravel or stone, which is then covered over with concrete. A two-by-four laid sideways can then be set against the basement wall. Concrete is added to fill in the gap. This technique creates a 1.5-inch gap at the perimeter of the basement floor that's designed to drain water from leaking basement walls down under the floor. Unfortunately, this gap is unsightly and tends to fill with dirt, objects, and other debris that collects from the basement floor.