Green Roofed Tree Houses
Go green. You’re already half way there anyway.
A tree house is build in a living foundation, why not give it a living roof? Green roofs are becoming more popular every year. They save energy costs for cooling and heating, they help remove pollutants from the air, and they just plain look cool. A rooftop garden makes a unique and eye catching addition to any structure, especially a tree house.
Construction & Materials
A green roof can be as simple as specialized growing trays that are just placed on the roof in squares, or fully integrated into the roof structure with watering and drainage channels. Green roofs consist of several layers. A vapor barrier and waterproofing layer on the very bottom made from EPDM or similar material will keep water from permeating the roof. The next layer should be a drainage system made from perforated plastic with dimples or ridges that will allow excess water to drain and run down the roof slope. On top of the drainage layer you will need a root barrier fabric that will allow water through but keep roots from growing into and clogging up the drain system. Because soil compacts after rain and can also eventually wash off the roof, an engineered growth media is needed that will retain its shape and porosity for healthy roots.
Roof gardens work best with plants that are drought and sun tolerant. Certain species of mosses and sedums are the most effective, some varieties of grasses can also be used. Perennial plants are the most obvious choice unless you plan to re-seed every spring which can be tedious and difficult on a roof.
A well-built green roof should need little maintenance. A modular tray system is the easiest to maintain because you can just remove trays to access the roof underneath. A built in system is not easily repaired, but if you use high quality materials and build your layers properly, it will last for many years with no issues.