Gutter Drainage Under New Concrete Drive: Slope and Outlet Are Key

Burying Downspout Drain Under RV Pad: Avoid Freeze and Erosion

Pouring cement RV pad next to garage. Want to bury gutter downspout drain under concrete. Concerned about erosion and freezing.

Critical Design Rules

1. Outlet must be lower than inlet – Gravity drainage only works downhill.
2. Unimpeded outlet – No blockages, critter guards.
3. Outlet protection – Gravel/rock basin at discharge unless tying into storm drain.

Pipe Specs

• Solid PVC (not perforated) for conveyance.
• Minimum 1% slope (1/8" per foot).
• Cleanout at upstream end.

If slope can't be achieved, use a pop-up emitter at grade—but burying under concrete requires positive slope.