Drainage around a house or property is one to the most over looked items when purchasing a home. Water is the enemy of any home or building and poor drainage just increases the probability for that water to cause problems.
Common problems that poor drainage around a home can cause:
- Foundation Deterioration: Excessive amounts of water can begin to deteriorate the integrity of concrete overtime. The foundation can become brittle and the concrete can crack when scrapped with a screw driver. Efflorescence, a white chalky residue on the interior of the foundation is often an indication of drainage problem on the exterior.
- Ground Settlement: As water continues to be absorbed in a concentrated location, the ground begins to settle. With no support from the ground, cracks will develop in the foundation and building structure.
- Termites and Wood Destroying Organisms (WDOs): Subterranean termites love consistently moist ground and need water to build mud tubes. With the right wet conditions, a subterranean termite nest can develop underground and infest the building structure.
Solutions:
Divert the water away from the building and property.
- Sloping surrounding surfaces away from the building. Current building code requires the surface grade to be sloped 6” inches away from the building within the first 10’ feet (5% slope). Impervious surfaces, like concrete walkways within 10 feet of the building should also be sloped away from the building at a minimum of 1/4” per 10 feet (2% slope). (CA Code R401.3)
- Extend downspouts 4 to 6 feet away from the building.
- Installing French Drains and or underground storm water system.
