I’ve a few questions about French Drains I can not find answers to anywhere… yet. Hoping you can help.
I am running underground solid and French drains around nearly all four sides of my house. All four sides will get a solid drain for downspouts and some surface drains, but part of the front of the house, one full side and part of the back will have a French drain – the area where subsurface water accumulates due to being downhill from my neighbors. The French Drain will be 4” perforated pipe, holes down, in 12 inch wide gravel trench, appropriately deep. The pipes will then run out my front yard, about 50 feet ling, to the street. Assume I have the slope correct to gravity flow everything. My questions are:
1. Do I have to drain each pipe separately, or at some point, can I merge my perforated pipe into my solid pipe?
2. If I merge my pipes, do I have to worry about water building up in the trench after the merge? Where is the best place for the Merge?
3. Where both solid and French share the trench, do I run these pipes side-by-side or can I put the Solid on top of the Perforated pipe? Does it matter?