There currently is no door, only the 8' poured wall (I've reserved a diamond chain saw to cut the opening). I hand excavated a portion of the drain tile and found that the 4" pipe is located alongside the footing, not on top of it.
I like the idea of reducing the pipe to a 2" solid (would pvc be a good choice?) and segmenting it underneath of the poured landing pad where the actual drain will be located. Do I need to worry about the exact elevation of the 2" pipe or does the water in the drain tile flow either way?
Additionally, since the drain tile is located alongside the footing, can I just tap the drain directly into it without cutting it?
Also, could you explain to me what a trapped drain is? Does this keep air out of the drain tile?