 Put a Living Roof on Your Modern Homestead
by Staff Writer
The living roof was utilized for hundreds of years because it is an effective
and affordable green roofing material, but it is gaining renewed interest as an
environmentally sound and sustainable green building practice. In its simplest
form, a living roof consists of vegetation, a growing medium, and a waterproof
barrier. Living roof implementations provide many environmental and economical
benefits to projects of all sizes in rural and urban settings. Before you start
shoveling sod onto your roof, however, there are a few things that you should
consider.
It is possible to retrofit an existing building with a living roof, but the
structure must be able to sustain the additional weight. The weight of the
vegetation, the growing medium, and the potential water-carrying load must all
be considered to ensure the safety of the building and its occupants. Average
yearly rainfall, temperature, and maintenance requirements must be considered
before committing to a green living roof. Proper design and planning will ensure
you enjoy the full benefits of a green roof.
Living roofs can be beautiful, but they also offer many benefits to the
environment. In urban environments, a green roof can collect a significant
amount of rainwater that could otherwise lead to flooding or overwhelm city
sewers and drain systems. The plants capture carbon and release oxygen into the
environment, and microbes in the soil can act with natural filtering processes
to clean and detoxify rain water. Habitat is created for plants, insects, and
other wildlife that would otherwise be lost. Living roof design also helps to
reduce the heat island effect in urban environments. Green roofs are great for
the environment, but they are also a sound financial investment for the property
owner.
The thermal mass of the living roof
regulates the temperature of the building by acting as a flywheel; it gathers
heat in the day and slowly releases it at night, which moderates the temperature
of the structure. The soil and plant matter has an additional
 cooling effect due
to the natural evaporative process. Sod or soil is a very good insulator and the
thermal mass helps to further reduce heating and cooling costs. The many
benefits of living roofs can be accomplished with a very simple design
consisting of several roofing layers.
Suitable roofs should already be watertight before the living roof is installed.
Insulation is placed over the roof structure and covered with a waterproof
barrier. Coarse gravel may be added, along with a system for water collection
and drainage. A filter of burlap, straw, or other synthetic
material can then be
placed to keep fine soil particles from entering the drainage system. At this
stage, sod, soil, or some combination of growing medium is applied to suit the
environment, structure, and expected vegetation. The success of the vegetation
and the benefits achieved depends on proper plant selection for your living
roof.
Vegetation for the living roof can vary, but short prairie grasses, mosses and
lichen, or succulents, such as Sedum, are popular choices. Succulents are great
for absorbing large quantities of water from the soil and then surviving through
periodic droughts. Grasses are great for shedding heavy rainfall once maximum
absorption has been achieved. The appearance of the living roof is also
important. Wildflowers have good properties and are favored by some green
homeowners who want a bright and whimsical appearance.
Living roofs do cost more than traditional roofs, but the initial investment
doesn’t take into account environmental benefits, greater durability and
efficiency, and the unique character of a living roof. Research green roof
options thoroughly first, but a living roof may be the best option for your
modern homestead.
|