Step 5: Remove Soil Elevators

Each tray arrives fitted with a 4-inch-wide band of white plastic, called a soil elevator, that allows the growing medium to rise 1 inch above the tray. Along with the curves built into the sides of each tray, the added height allows soil-to-soil contact between the trays so that water, nutrients, and beneficial organisms can move laterally among the trays. Sharing the available water reduces the chance that dry or excessively wet spots will develop. After a couple of rows of trays are in place, the installer pulls out the soil elevator at an angle to avoid removing the growing medium. This helps the roof blend together almost instantly and reduces air space between the trays, increasing the system's insulating R-value.
Ask TOH users about Green

Contribute to This Story Below

    Tools List

    • 16-foot tape measure
      Tape measure
    • drill
    • concrete saw
      Concrete saw with masonry blade

    Shopping List

    1. EPDM

    2. Modules

    3. Engineered soil

    4. Sedums

    5. Aluminum edging