I'm stumped and I hope someone on this board can help me figure out why my exterior drain is setup the way it is.
This drain is at the bottom of an exterior stairwell. There's a wooden grate and under this grate is a trench/rectangle in the concrete. On the left and right sides of this rectangular hole are two 4" drain pipes that hook up to the main sewer line. In the middle of this is a vertical 2" pipe.
At first, I assimed this vertical drain pipe was to drain any water but it was full of dirt and rocks. When I removed this debris, it didn't drain anywhere.
1. What would be the puprpose of this 2" vertical drain pipe given that the horizontal (and working) drain pipes would drain any water that collected in the rectangular hole.
2. After cleaning the 2" vertical pipe, it doesn't seem to drain into the sewer line. It just seems to stopafter about 3 feet. Some people have said that older drain pipes in homes built in the 1950s drained to a small gravel pit and not to the main sewer line. Does anyone have thoughts on where this drains to?