The wood sill plate sometimes referred to as a mud sill is located at the top of the basement foundation wall where the house is connected. This critical junction between the concrete foundation wall and the wood framing should be perched up out of the ground a minimum of 6″ by code. When this sill plate is at or below the grade that it is adjacent to, it can be inundated with water accumulation and have little resistance to water penetration. The result is water flowing over the top of the foundation wall and flooding the basement.
There are numerous reasons the sill plate may be buried in the ground. It could be the way the house was originally constructed or planters that were added afterwards. It is not uncommon for landscapers to raise the grounds around the structure with materials that raise the elevation. Sometimes the horrendous mistake of adding soils to create a pitch away from the house is the cause. Regardless, once the top of the foundation wall is not visible, it is subject to water intrusion because there is no waterproof barrier bridging this location by design. Making matters worse, if the wood structure comes in contact with the soils and not allowed to dry out, rot occurs and termites are introduced. At this point, a structural catastrophic failure could occur if the bottom of the house is not restored.
Boccia Inc. has unique, proprietary solutions to correct this condition. They can remove the soils and install filtered perforated pipes in a drainage stone envelope adjacent to the exterior side of the sill plate. This creates a void in the ground that will drain the water immediately so the wall will not sit in a saturated ground condition and allow the framing and façade materials to dry out. Their system may discharge to daylight, when a pitch is available, or drywells. Some situations may require that these drainage systems are incorporated with sub floor pump systems to remove the water. Part of a Boccia Inc. Sill Plate/Mud Sill system is the installation of a membrane at the top of the foundation to create a belts and suspenders comprehensive project that will eliminate the potential for water intrusion.