I'm doing a garage addition on a slightly sloping small city lot in Seattle. The garage floor slab will be at finish grade and the footing is 18" below the top of this slab. Must a footing drain be installed along the footing or can it be installed at or below the basement slab along the foundation wall? If it is installed at the footing I can not drain to daylight, but if it is installed along the wall just below the elevation of the slab i can drain to daylight.
It sounds like if your drain exit is just below the floor, then with pitch it will be above the floor around the sides doing no good, no? I would either raise the slab slightly above grade in the front or forget the drain to light and just run extra perf pipe with common practices like in stone with silt barrier etc. Draining to light is great until some frogs make a mud nest up there or something and it backs up. really... not funny.