I have steep slope in my backyard and I hired a contractor company to build a 4 feet average retaining wall for me so that slope can be leveled. They are almost done and now are saying there will be 1-1/2" of slope from back of foundation to behind the wall. He mentioned its required for drainage.

Do you really need that much for just 15 feet built flat area from back of house to behind the wall?

  • 1
    Since we commonly have people swap them up with ' .vs. " - 15 inches or 15 feet from foundation to retaining wall?
    – Ecnerwal
    Aug 26, 2022 at 3:40
  • just updated, yes its 15 feet not 15 inches. thanks for correcting me.
    – PowerTech
    Aug 26, 2022 at 12:14
  • @Ecnerwal I checked it now 4 inch of slop. I am putting sod for now in the leveled area if cap is exposed. and But they are saying if sod needs to be flush with sod, then we should be fine. Does Sod/Paver goes flush with cap ?
    – PowerTech
    Aug 27, 2022 at 13:02

1 Answer 1


Drainage slope is needed.

If there's only 15 inches behind the wall, that's quite a bit more than the minimum.

If there's 15 feet, it's just about the minimum.


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