Internal Waterproofing Procedure

Foundation interior drainage systems are one of the most important aspects of residential construction. Drain tile systems are also one of the most misunderstood aspects. Because these systems are buried and cannot be easily modified or corrected, it is vitally important that they are installed correctly Foundation drainage systems, which are installed properly, can serve a dual role.

Foundation drain tile systems are the means by which groundwater can be transported away from your basement. If you want a dry basement and a sound foundation, you must have an adequate foundation drainage system. The water content in the soil surrounding your house can fluctuate seasonally. There is always a point at which you can dig and hit water. Geologists often refer to this as the water table. This water table rises and falls in response to the amount of precipitation in any given time period. The water table in many parts of the country can rise to within a few feet of the surface during wet spells. Water will take the path of least resistance. If there is no exterior waterproofing water can go sideways through a crack in your foundation, or it can go down alongside your foundation into a pipe. I’m sure that you will agree that it is a better idea for the water to go down into the pipe.

Interior drainage systems work extremely well for many customers. Depending on your circumstances, this may be an effective solution. Many water control system companies claim to be waterproofers and offer this method as a solution to every basement water problem. If a company proposes opening the floor on the inside for any reason, they are offering an interior drainage system. Only an exterior excavation to the footer or bottom of the foundation accomplishes waterproofing. Never contract for a water control system if dampness, seepage, and or cracking on the walls are your concern, as this may result in further damage to your foundation.
Pressure relief systems, also known as drainage systems and French drains, are an extremely efficient way to prevent water seepage through the basement floor caused by hydrostatic pressure. Hydrostatic pressure is the force exerted by water against an item such as a foundation. When the groundwater levels outside the basement rise above the level of the floor, the basement acts like a boat in a pond. If a boat is sitting in water, water will leak in through any open cracks, holes or porous areas. It works the same way with a basement. Hydrostatic pressure can push water through hairline cracks. Symptoms of this are water coming up through the basement floor or water coming in at multiple locations.

To de-water a basement from the interior, a perimeter drain must be installed. In cases where water is coming up through the floor, we prefer adding lateral (front to back) drain pipe to collect water before it comes in contact with the underside of the slab. The water is transported away from the basement, preventing floor water, and flooding. If a basement has a concrete slab floor this will entail breaking the floor at the walls and/or across the floor and installing drain pipe that leads to a sump-pump or gravity drain, and then re-pouring the broken sections of the floor. If grade conditions and slope of land are adequate to accommodate a gravity drain, or you build on a hillside, your drain tile pipe will simply ‘daylight’ or come to the surface. It is a much more reliable system, as you do not have to rely on electricity to discharge the water in a torrential rain, your system depends entirely on gravity to work. If you build on level ground, you have basically two choices, install a sump pit or a large buried french drain. A french drain pit is a large subterranean pit filled with gravel. The drain tile pipe runs to this pit and the water fills this pit. French drains do not work well in areas where the water table rises above the level of the French drain pit or the basement floor. A sump pit is installed inside the basement of your home. The drain tile pipe runs to this sump. The collected water is then mechanically pumped from the sump and away from the home.

Internally we are redirecting the water and thus not letting it remain standing in the structure of your basement. Remembering that we want to keep the structure, not just the living space, as dry as possible, we put the weeping tile beside the footer. You can keep the basement dry with a drain installed on top of the footer, or even with a “baseboard” system. However, using these last two methods, the footer is permanently high in moisture. This means that over time it will begin to crumble and start to disintegrate, impinging on the integrity of the complete building. As a repair, for an existing problem, the following happens:

• Trench the floor slab.
• If the walls are made with “block” drill holes into the hollows.
• Install low-level drainage board.
• Install weeping tile.
• Install a layer of gravel.
• Refinish the floor.
• Install a sump pump and connect new weeping tile to it. Connecting the weeping tile to a floor drain is possible, but generally not advised, in some instances.

Whichever method you decide to use, get it done professionally as a job done properly protects your investment and should give you peace of mind in the form of a 30 years warranty.