Interior French Drains in Knoxville, TN

Often it doesn't. If the water is coming from one side, a drain along that wall and around the corner can be enough, and the silt lines and wet soil show where it needs to run. Where water enters from several sides, a full loop is usually the better use of your money, and we'll tell you which one your space needs.

The pipe sits in washed gravel, and in silty ground a filter fabric goes around the gravel so fine soil can't wash into the perforations. A steady slope toward the outlet keeps water moving fast enough to carry small amounts of sediment through. Where a sump is part of the system, the basin gives you a place to see and clean out any silt.

Yes. The drain goes in the ground under the liner, so it has to be done before or alongside the encapsulation, and a liner laid over a wet floor only hides the water. If you're doing both, have them quoted together so the liner is laid out around the drain and sump from the start.

Often, yes, though low clearance slows the work and changes how the trench is dug. We measure the clearance at the estimate and look for any stretch that's too tight to work safely. If part of the space can't be reached, we'll tell you plainly and explain what that means for the layout.

One of two places. If the lot falls away from the house enough, the pipe runs out through the foundation wall to a gravity outlet down the slope. If the yard is flat or falls toward the house, the pipe feeds a sump basin and a pump pushes the water out through a discharge line routed well away from the foundation.

It catches what runs down the inside of the wall and reaches the floor, and it relieves water pressure in the soil along the footing. The block itself will still get wet. Where the wall is soaked from outside, an exterior drain or better grading on that side may be part of the answer, and the estimate looks at both.

The trench runs along the perimeter wall and stays clear of the interior piers. Where a pier sits close to the wall, the trench is laid out around it. If we see a pier that has already settled or cracked, we'll point it out, since that's a support question to deal with on its own.

Shallow rock is common around Knoxville, and it does change the job. The trench depth follows what the ground allows, and the pipe can be routed around ledges. In a few spots the drain may sit shallower than ideal, and we'll explain at the estimate how that affects what it can collect.

Very little. A gravity outlet should be kept clear of leaves, soil and mulch so the water can get out, and a sump pump is worth testing a couple of times a year by pouring water into the basin. If you ever see water sitting in the crawl space again after a storm, call us and we'll check the outlet first.

Partly. Removing standing water and wet soil takes away a big source of moisture, which helps. The smell usually comes from humid air under the floor, though, and that's handled by a sealed barrier or encapsulation with a dehumidifier. We'll tell you whether your space needs one, the other or both.