Discharge into underground drainage system: Drain(s) discharge into an underground drainage system. The condition of underground portions of the drainage system cannot be inspected.
Limited visibility of/access to drain: Visibility of, and accessibility to, the drain limits the inspection.
Stairwell drains require periodic cleaning, risk of water: Stairwell drains require periodic cleaning. Clogged stairwell drains which overflow can permit water penetration into the home.
French drain is underground water catchment system: A French drain is an underground water catchment system installed in areas of poor drainage. French drains can alleviate hydrostatic pressure at the point at which surface water control or drainage is problematic and hard to correct by grading. The purpose of such a system is to divert surface water away from points at which water tends to enter the sub-grade areas of the dwelling. French drains are not visible for inspection, and are not evaluated during a home inspection.
Basement floor drains equipped with one or more Palmer valves: The basement floor drains are equipped with one or more Palmer valves, which were popular from about 1920 to 1950. These permit water to exit the drain into the sanitary waste (sewer) system, but prevent waste water or septic gases from entering the basement. Many municipalities require elimination of Palmer valves in favor of sump pump systems. Assessing the operational function of a Palmer valve is beyond the scope of the inspection.