1. Check the outlet connection first
Before installing any channel, locate the underground drainage system the channel will connect to. Confirm the pipe size, invert level and position. The channel outlet must connect to this pipe — the channel system is only as useful as the drain it connects to.
2. Establish the installation depth
The top of the channel grate must be level with or fractionally below the surrounding surface. Work back from the finished surface level and the outlet pipe level to determine where the channel bed should sit. Check the available installation depth against the product's overall depth — some products, such as shallow channels, are specifically designed for restricted-depth installations.
3. Plan the run layout
Determine the start and end points of the channel run, the direction of fall (if required), any corners or junctions, and the position of the outlet or sump unit. Mark out the trench accordingly. The trench must be wide enough to allow the concrete surround to be placed around the channel.
4. Prepare the sub-base
Excavate the trench to the required depth and compact the base. A stable, compacted sub-base is essential for the long-term performance of the installation. Do not install channels directly in loose or uncompacted ground.
5. Lay the concrete bed
Pour a concrete bed to the correct level for the channel to sit at the right finished height. For driveway and commercial applications, follow the specific mix and thickness requirements in the manufacturer's installation guide. Use a lean mix or a mix appropriate for the load class.
6. Set the channels in sequence
Starting at the outlet end, place the channels in sequence. Ensure each section is correctly aligned and that the joints between sections are correctly formed. Use temporary supports if needed to hold the channel in position while the concrete is placed around it.
7. Place the concrete surround
Place and compact concrete around the sides of the channel to the depth and width specified in the manufacturer's installation guide. The concrete surround transfers load from the surrounding surface into the ground — it is critical to the structural performance of the installation. Do not omit or reduce the surround.
8. Allow curing time before use
Allow the concrete to cure fully before trafficking the installation or placing the finished surface. Early trafficking before the concrete has reached adequate strength can damage the installation.
9. Install the grates last
Do not install grates until the surrounding surface is complete. This prevents damage to the grates during construction. Check that grates are correctly locked in position before opening the installation to use.
10. Check the outlet connection and flow
Before completion, check that the outlet connection is watertight and that water flows freely from the channel into the underground drain. Flush with water to confirm. Clear any debris or mortar that may have entered the channel during installation.