How to Maintain the LiveRoof Green Roof System
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How to Maintain the LiveRoof Green Roof System

January 6, 2020

During March of each year, an annual soil
test needs to be conducted and the pH and fertility levels should be monitored.
The pH should be maintained in the range of 6.5 to 8.0. Given
that the LiveRoof soil media is formulated to be buffered against acid
rain, changes in pH should be gradual and amendment seldom required. In the event
that the pH falls outside of the 6.5 to 8.0 range,
immediately consult LiveRoof LLC for the appropriate amendment. If fertility
is below the normal level, LiveRoof recommends a single spring time
application of NutriCote triple 13 type 140 or 180 at twenty pounds per
thousand square feet. These have release periods of 140 or 180 days. In all cases,
the NutriCote label directions for application rates should be followed and
take priority over any recommendations listed here. Read the product label and
follow label directions. NutriCote releases nutrition gradually and
minimizes the effects of fertilizer runoff. Run off potential however exists
in all cases, and should be evaluated by the applicator in accordance with
site specifics. The greater the runoff sensitivity the lower the application
rate. All applications of fertilizer are the sole responsibility of the
applicator. While successive watering might never be needed to keep the green
roof alive, it should be used as a management tool under the following
conditions: prolonged hot dry weather. This is generally defined as periods of
75 degrees or above with less than one inch of rainfall per month. This applies
to the northernmost temperate zones such as Seattle, Minneapolis, Toronto, and
Boston with a LiveRoof Lite module at two and a half inch soil depth, this is
shortened to about two weeks in the northernmost temperate zones. Water
requirements of course vary with geography, climate, windiness, and plant
selection, and the farther south, windier, and hotter the climate, the greater and
more frequent the need for irrigation. Protracted hot dry weather, especially in
windswept locations, can dry out the green roof substrate and cause the
plants to go dormant or die. During hot dry windy weather it’s wise to check the
plantings regularly and look for signs of wilting and stress. These are
indicators that it’s time to give your LiveRoof® additional water. With
protracted warm or hot weather, plants can potentially be killed. Even dormant
plants which returned to a growth mode when conditions become favorable will
shrink to a smaller size and expose soil, which can predispose the plantings to
weed encroachment. When hot dry weather persists thorough irrigation is
recommended and should be conducted to the point of runoff. This allows the
plants to avoid dormancy. Cover the soil effectively and keep the evaporative
cooling effect of the green roof working. Weed control inspection and hand weeding
should be conducted every two weeks. The process is simple. Pull any and all weeds,
no matter how small and never allow any weed to flower set seed or complete its
life cycle. The byproduct of this regimen is that each inspection and weeding
event requires minimal time as weeds are headed off proactively. The regimen
should be conducted from spring through fall in areas where the roof becomes
frozen and snow covered in the winter. In warmer climates, it should be continued
year-round. The inspector or weeder may adjust this interval in accordance with
seasonal variations in weed growth. But, at no time should the interval be longer
than two weeks or long enough to allow for any weed to flower and set seed.
Never allow a woody plant to establish in a green roof system. Woody plants have
extensive root systems that can damage roofing membranes. Herbicides, whether
pre-emergent or post-emergent, are not recommended. Herbicides are not healthy
for the environment and can contaminate runoff water. The need for pre-emergent
herbicides is a sign of weeding too infrequently and therefore should never be
a problem if LiveRoof inspections are handled properly. Pesticides are also
discouraged and should always be considered secondary to cultural and
biological control measures. Pesticides also get into runoff water and cause
environmental damage. In almost all cases, any infirmities with LiveRoof plants
will be caused by unusual weather events and be temporary in nature. Pesticide use
should only be conducted on an as-needed basis and then only by qualified and licensed applicators. All applications of pesticides are the sole responsibility of the applicator.
Nesting birds can potentially displace soil. During routine inspection any
displaced soil should immediately be replaced only with LiveRoof brand
engineered green roof soil. Sweep and clean up any soil that’s left behind.
Roof drains should be inspected every two weeks. And any debris, pebbles, leaves, etc should be removed to keep drains flowing freely. Any debris or trash
should immediately be removed at every visit especially during fall and spring.
LiveRoof plantings should be raked clean of any matted tree leaves which could
smother the green roof plants. LiveRoof LLC recommends that once a year, around
the first of April, the green roof be mowed or weed whacked to break up any
dried seed heads and chaff. The clipping should stay on the roof and not be
bagged to removed. This regimen has a rejuvenating effect on the plant
material and keeps it looking fresh. Foregoing annual mowing may be elected by
the owner. Be safe and use proper protective equipment. Specific dates of
maintenance and site inspections may vary based on local weather conditions
or client preferences. But, the interval should not exceed those recommended. A
log should be kept to track maintenance visits. This log should indicate staff
member, date, activity, and time. If ever a module needs to be moved, carefully
follow these guidelines. With a dull flat bladed spade, probe the soil for a
container edge, with a dull instrument, such as a handle of a spoon or a dull
butter knife, dig back a few plants and expose the container edge. Never cut or
damage roof membranes. Then with the same dull instrument, cut along all four
sides of one module. Using a pair of pliers or vice grips, grasp the lip of
the container and lift it up to expose the roof surface. Successive modules may
be removed in similar fashion. Replace vegetated modules by simply setting them
back on the roof surface with the overhanging lip oriented in the same
manner as the installed modules, so that the lip inserts into the moisture
portals of adjacent module. Be sure to remove any
soil or gravel prior to replacing modules. This can be done with a shop
vacuum. Understand that each roof design is unique and you have to use your
expertise and judgment to cope with the nuances of each job you should always
adhere to proper roofing and horticultural principles, and know that
as an installer, you’re responsible for the quality of each LiveRoof
installation. If the roof isn’t a flat roof, consult your architect to discuss
appropriate containment. The need for this may vary with the size of the roof,
slope design, and local climate. Never take risks or offer advice regarding
slope or containment. Involve the expertise of a qualified engineer to
ensure safety and effectiveness. Keep in mind that the LiveRoof standardized
procedures are not intended to be comprehensive in respect to roofing
principles. Ultimately it’s the Installer who accepts responsibility for the green
roof installation. Including but not limited to, protecting the integrity of
the waterproofing system and building, caring for the plants on the jobsite and
during installation, placement of accessory components, and proper
installation of the LiveRoof modules. Because LiveRoof LLC and affiliated
LiveRoof growers don’t conduct the installation, neither live roof LLC nor
LiveRoof affiliated growers accept responsibility for the actual
installation. We hope that the LiveRoof standardized procedures serve you well
as you represent your company, the building owner, and the LiveRoof brand.
You should always take great pride in the quality of your installations and be
proud that by installing LiveRoof you’re helping to make the world
a better place

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