I'm going to put a 4" perforated pipe. But my question is about the necessity of backfilling.
The trench is as low as the bottom of the footing, at least a foot deep from the top of the dirt and about a foot and a half wide. We kinda had to dig wide for us to be able to walk. But now I can see how this may have been an overkill since I have to fill it with gravel. That's going to be a lot of gravel! Something like 250 ft3!
So the question is do I really need all that gravel? Do I need any at all? Can't I just put a pipe wrapped in garden fabric?
I'm also considering using NDS EZ-Drain although it's quite expensive at $45/10'. If I use that, it's not going to fill the trench. So again do I need to backfill with gravel?
What's the purpose of the gravel in general? I can understand how gravel is better than soil to allow the water to flow, but isn't an empty space even better?