A basement can be plagued with standing water or persistent moisture as a result of seasonal flooding, a high water table, poor exterior drainage, or other factors. Various exterior or interior drainage systems can be implemented to provide relief. Although a drainage system installed within a basement, by its very nature, does not make the basement waterproof, a properly installed drainage system will capture water and direct it under the basement floor to prevent it from entering the basement itself.
Addresses
1. Break up the concrete slab around the perimeter where the drain will be placed. Trench, but avoid damaging the base of the wall, which must remain intact to support the wall.
2. Dig a trench at least 6 inches wide and about the same depth next to the footing. When digging, keep in mind that the trench and pipe to be laid later should slope slightly toward a sump pump or other outlet, and be higher than any inlet into the sump pit. Typically, only a 1/4-inch change in elevation is necessary.
3. Drill a series of 3/8-inch-deep holes along the base of the wall with a rotary hammer if the wall is made of cinder block or hollow.
4. Place about 2 inches of clean, coarse gravel in the trench, making sure to maintain the slight slope established at the bottom of the trench.
5. Lay the drain tile in the trench, checking again to make sure it slopes toward the sump pump. Use an adapter, if necessary, to attach the drain tile to the sump pit.
6. Fill the space on both sides of the drainage tile with gravel.
7. Install a flange that extends from the trench to the wall. The flange should be designed to leave a small gap between the flange material and the wall for water to flow down the wall directly into the drain.
8. Backfill the remainder of the trench, to a height where a patch of concrete of the desired thickness can be placed and flush with the existing floor surface.
9. Cover the excavated trench area with a concrete patch, trowel it down, and smooth the surface with a trowel.
10. Install panels on basement walls, if desired. Use drive anchors instead of an adhesive to provide space for moisture seen through the wall to drain into the flange. Use a panel made of a material that does not allow mold to grow, such as fiberglass.
11. Route the discharge pipe or sump pump hose far enough away from the house and other structures and make sure the landscape slopes away from the house so that water cannot easily re-enter.
