What it is
100-foot coil of 4-inch black HDPE drain pipe — un-slotted, smooth interior. The companion product to the perforated drain pipe used in French drains.
What it's for
Carrying water from a French drain (or a downspout, or a yard drain) to where you want it to come out. Anywhere you want water to flow through without entering the pipe, use solid. Anywhere you want water to enter the pipe, use perforated.
The pattern: perforated pipe in the rock-filled trench (the collection zone), transitioning to solid pipe at the end of the rock for the run to daylight, a curb cutout, or a pop-up emitter at the property line.
Other uses:
- Downspout drains — fully buried run from the downspout to the curb or a remote discharge point. All solid pipe.
- Sump discharge — pumping water from a sump out to a discharge point. Solid pipe.
- Under driveways and walkways — anywhere the pipe passes under traffic, switch from perforated to solid so water doesn't enter under a slab and cause heave.
How much do I need
One coil covers most residential outflow runs. Length depends on how far you're moving the water:
| Outflow run | Coils needed |
|---|---|
| Under 100 LF | 1 |
| 200 LF | 2 |
| 300 LF | 3 |
Connect to perforated pipe with a standard coupler. Connect to a downspout with a downspout adapter (also sold at the yard counter, around $5).
How to install it
- Trench at 1% slope (1" drop per 8 LF) toward the outflow.
- Lay the solid pipe in the trench, joints connected with couplers.
- Backfill with native soil — solid pipe doesn't need rock around it.
- End with a pop-up emitter, an open-end discharge at a curb cutout, or a daylight termination in a swale.
For drainage runs under driveways or walkways, encase the pipe in 4-6" of crushed limestone for crush protection.
Buying tips
- Pop-up emitters are sold at the counter — about $12-15 each. Nice finishing detail at the discharge end.
- If the run goes through landscape beds, mark the pipe location at install time. You'll forget where it is by next spring and a shovel through the pipe ruins the day.
Contractor notes
Bundle deliveries with perforated pipe and drain rock for French-drain installs.