DIY Projects

By Jodie Zhang -

How to Install a Modular Green Roof

The benefits of green roofs are widely acknowledged. Having one in place reduces and filters rainwater runoff, and moderates the microclimate around your house. Green roofs help insulate in the winter and cool in the summer, and extend the lifecycle of your roof by 2-3 times its normal lifespan. Using a modular system is a quick and highly effective way to install a green roof of your own.

Supplies:

  • The modular installation method outlined below requires a certified contractor to do the work. For this project, we are using a system such as LiveRoof, whose modules come pre-vegetated. LiveRoof uses a growing medium in place of soil, and offers a range of plant options.
  • It is also prudent to have a structural engineer verify that your roof is able to sustain the extra weight, and help you make structural alterations in the form of joists or bracing. Also, additional waterproofing to the roof may be needed before green roof install.

Instructions:

  1. A modular system like LiveRoof comes ready for installation. Each 1’ x 2’ module weighs 40 lb, and are pre-vegetated in a nursery for four months before they are brought on-site. We recommend selecting a drought-resistant hardy sedum.
  2. Install an aluminum trim around the edges of your roof to restrain and disguise the planters behind it. The planters interlock with one another, and can be individually removed for easy maintenance. ½” legs raise the plants off the roof surface to allow for adequate drainage.
  3. Lay the modules one by one until the row is complete. End pieces may have to be measured and cut. The LiveRoof system will require a heavy-duty saw and blade to cut through the planter and dense growing medium.
  4. Once the modules are in place, a layer of plastic wrapping called the soil elevator is removed. This step joins the soil and creates a seamless look. The certified contractor’s job is done, and the green roof is complete.
  5. Finally, settle the growing medium by giving your green roof a nice watering.

Maintenance:

Maintenance requirements for hardy sedums are minimal. Give them some extra watering if they have received less than ½” of precipitation in a two-week period, especially if temperatures rise over 85 degrees Fahrenheit. Spot weeding is recommended, paying special attention during dry spells.

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