Catch Basin Installation
Catch basins help collect surface water and redirect it into to a designated discharge area. Here’s how we install them properly while maintaining flow and strength throughout the system.
Step 1: Adjust the Trench
Ensure the trench has enough width for the basin to sit flat and for other pipes to be navigated around it, if the system requires other pipes. The trench should be deep enough so that the pipe can plumb in straight, and that the top of the basin will be 1-1.5" below natural grade. Backfill the area with gravel if the basin needs raised. Measure and set aside the pipe you need.
Step 2: Cut the Basin Hole
Select the predefined knockout that allows the pipe to stay flat in the trench. If needed, warm the basin slightly with a torch to make cutting easier using a utility knife. In most cases you will need to cut at least 2 holes.
Step 3: Drill Holes in Bottom
Drill a 3/8" hole in the center of the basin to allow water to drain in the hours following a rain event.
Step 4: Install Pipe Locking Rings
Set aside the screws which are taped to the locking rings, you will need them for the basin lid. Install the included locking rings, which allow installation of the pipe to the basin. The larger piece (labeled "1") goes on the outside with the bell pointing inward, and the smaller piece (labeled "2") goes on the inside. Twist the inside piece clockwise to secure the locking rings.
Step 5: Trim for Pipe Size
Cut the predefined hole in the larger locking ring piece with a utility knife to match your pipe diameter (generally 4").
Step 6: Create Flexible Opening
From the inside edge of the hole that you just created, cut slits outward about 1" apart all the way around to create flexible flaps. This makes pipe installation easier while maintaining a snug fit. It also reduces the possibility of the pipe slipping out, since we don't tape this joint.
Step 7: Insert the Pipe
We use blue FrenchDrainMan pipe for catch basin connections. Push the pipe into the basin, ensuring it does not extend more than 2" (about 3 ribs) into the basin. If the pipe does, use a Sawzall to cut any excess carefully.
Step 8: Install Weight
For 20" or larger basins, place a concrete “biscuit” at the bottom to keep the basin from floating after heavy rains or high water tables.
Step 9: Attach the Lid
Use a screwdriver and the saved screws to secure the lid flush to the basin. Do not overtighten. If gravel will be added later for the installation of a French drain, cover the lid with 4" pipe tape and remove it after backfilling to keep the basin clean.
Step 10: Level the Basin
Before backfilling with gravel or dirt, ensure the basin is level and flush with the surrounding grade. Adjust as necessary during backfill.
Step 11: Cut Fabric
If the catch basin system is part of a French drain, cut and wrap the drainage fabric around the basin as shown in the image.
