Running a Roof-Leader Underdrain Under a Finished Paver Walk

A roof leader that dumps on a new walk will rake polymeric sand out of the first three courses in one wet season. On Pinellas lots the better detail is a sleeved underdrain that carries the water under the field to a pop-up emitter, a legal daylight point, or a catch basin the owner already has.

PaverForge Hardscapes sets the sleeve before bedding sand. The pipe sits in the base, not in the sand bed, so a later plate-compactor pass does not oval the line. We keep a minimum cover so an 80mm walk does not telegraph the pipe as a ridge.

At the downspout we use a leaf adapter the owner can clean. At the outlet we do not tie into a city structure unless the permit packet calls for it. Splash basins at hose bibs are a different detail and are quoted separately.

Underdrain rules we follow

• Sleeve in the base, never in the bedding sand.

• Pitch the line off the house; do not trap water at the stoop.

• Leave a cleanout where the run is long or dog-legged.

• Do not discharge onto a neighbor or a public sidewalk.

Ask for a roof-leader detail when you send patio photos. Call 727-490-9798.