Ask an Expert: Creating a Green Roof

By Tracy Nelson, Executive Director of the Lower Ninth Ward Center for Sustainable Engagement and Development

What do I have to do to prepare my flat garage roof to be a green living roof and collect rainwater?

Introducing a living roof is a great way to extend the life of your garage surface, make a blah space beautiful, and create a cooler interior for your garage. And there is an easy strategy for collecting rainwater that you can put into motion yourself.

A flat surface is a good place for a living roof garden. The two most important design decisions are: finding the best method to waterproof the surface of your garage, and determining the type of foliage you want growing up there.

In the living roof world, there are three types of green roofs that vary in weight, depth of soil and the type of foliage that can be grown. These systems are extensive (least expensive and lowest maintenance), semi-extensive (heavier and requiring some maintenance) or intensive (living roofs which are more like walkable gardens.) If your garage has asphalt decking, the extensive system is best, as it is the most lightweight. This will grow a variety of sedums and other plants with shallow roots. If your garage has a concrete deck, you can go the semi-extensive route which has a deeper layer of soil and can grow a wider variety of plants, such as wildflowers. READ MORE >>

Tracy writes the monthly column, "Ask an Expert", for PRC's Preservation In Print.

Excerpt courtesy of the Preservation Resource Center of New Orleans.