We left off last time discussing the water table and its role in causing wet soggy back yards and a damp basement. As we explained, the rain and melt water that percolates down into the earth’s crust, will eventually join up with the natural underground springs and sources, which are present in every locality. The upper level of this subterranean water when it is fuelled by heavy rains, can, and often does, rise up close to the surface of the ground around your home.
When the water table reaches the level of your foundations and footings, it is poised to cause most of the dampness and basement waterproofing problems that are commonly found. The positive hydrostatic pressure, as the outside water pressure pressing against your home is called, acts powerfully against your foundations, seeking out every little crack and fault in the structure, and can eventually lead to dampness forcing its way into the interior of your home.
Once we know the cause it becomes possible to review the problem and provide solutions that will leave you with a dry, comfortable basement and interior.
Drainage: the most powerful tool for relieving dampness problems.
Unless you are growing rice in a rice paddy, soggy water logged fields are highly unsuitable for most farming purposes! So for hundreds of years, farmers have been using various forms of surface drainage to lead water away from the fields where they plant their crops, to more suitable locations, such as dams and reservoirs.
The simplest system is to dig a ditch into which the surface water flows. The ditch is graded so that it slopes gradually away from the area where you want to maintain dry earth. The obvious drawback is that an open ditch is a hazard, and obviously not suitable in locations where your livestock runs the risk of falling into it! Enter the French Drain!
The French Drain At Its Simplest: Using Natural Materials
At its most rudimentary, French Drain may be nothing more than a ditch or sump filled with rocks or coarse gravel. This will capture runoff water allowing it to drain down to the bottom of the pit, where over time, it will be absorbed into the earth. Naturally this will only provide a partial and localized solution, aside from the fact that it is unsightly and impractical in residential locations.
More Sophisticated Applications
The most commonly used technique makes use of perforated pipes that are laid in a custom dug trench. The pipes extend all the way along the trench and allow water percolating down into the trench, to enter the pipe and be led away to a suitable locality, where it can either discharge naturally, or be pumped further away.
The trench, around the pipe, is filled with semi-permeable material that allows surface water to filter down easily until it enters the drainage pipe through the many perforations in the pipe surface. The trench is then covered with a suitable layer of soil and planted with grass or other vegetation, so that it matches the surrounding area.
The drain can be led to an area where one may wish to collect the water for irrigation purposes, or in a residential location, into the city water system.
How Can This Be Applied In Your Home?
Experienced drainage and waterproofing companies use a variety of different techniques, tailored to each individual damp basement case and budget. The next article will outline some of these in more detail.
Give us a call and we will provide a detailed report to suit your needs.