What should I know about Basement Drainage?
Leaks involving the drainage system are characterized by water entering through the floor or the cove area, the joint where the floor and wall meet. A foundation and waterproofing repair specialist will be familiar with the necessary methods and equipment to resolve the matter. Common maintenance issues to inspect before contacting a professional include:
Check the grading: Dirt around the home must slope away from the foundation.
Gutters: Keep gutters free from leaves and debris. Downspouts may need to have added extensions. Placing them at least four feet away from the foundation ensures minimal water saturation.
Window wells: Poorly draining window wells will lead to leaks.
Driveway: Patch all cracks to prevent misdirected water.
Floor and Drain System Leaks
For leaks entering through the floor or drain system, the cause is often related to the structure sitting on a high water table. Interior sub-floor drainage systems in combination with a sump pump system are usually ideal to resolve the constant presence of water. The advantage offered is that these drainage systems are less costly and easier to install than the traditional exterior systems requiring excavation.
French drains also work well in getting rid of excessive underground water. The surface inlets remove the water and are pumped away from the structure foundation. Backwater valves deter water overflow from the main sewer drain from backing up into other outlets in the basement: sinks, tubs, showers, floor drains.
Localized leaks do not always indicate drain tile failure. These types of leaks can be caused from localized water saturation or soil settlement. Drain tiles fail because they are damaged from either soil settlement or foundation shifting. In older homes, decaying drain tiles can cause problems depending on the material that had been used. This is quite common with the clay drain tiles that were in standard use some years ago.
Cove Area or Floor/Wall Joint Leaks
Water penetration from the cove area is often attributed to water pooling at the foundation perimeter. This condition causes soil displacement, and the swelling lifts the building structure, allowing water to move under the foundation. If there is still water moving under the foundation approximately a year after modifying the source of the drainage problem, a moisture barrier placed several feet below the surface is necessary.
Because the soil composition and footing wall floor construction are not standardized from one home to another, it is much more reliable to analyze soil and footing configurations with the floor open. The key factor to installing a lasting and effective waterproofing and drainage system is in accurately identifying the footing configuration in relation to the floor/slab and the foundation wall.