Living Wall Structural Considerations
The LiveWall system WallTer planters weigh from 10-15 lbs/SF when fully grown and watered, making it suitable for most indoor and outdoor wall applications. To assist you with determining whether your structure can tolerate this load, we have commissioned an engineer to calculate the vertical gravity loads and lateral wind loads of the LiveWall vertical garden product.
If you wish to learn more about the equivalent wall pressure, maximum bending movement and equivalent uniform wall pressure, download the engineering report.
“Peet's Coffee was our first LiveWall project. LiveWall helped us each step of the way so the installation was simple. I look forward to doing more green wall projects with LiveWall.”
- Sheldon Cohen, president, Green Interior Plants Solutions
Functionally, LiveWall can be placed as high as your building infrastructure, plumbing, and ability to access it for maintenance will allow. But, as with any siding, high wind can pose a threat to the security of an outdoor living wall siding. The LiveWall System provides excellent wind stability when properly installed. To do this, a review of wind pressure and associated variables, such as the building's geographic location, surrounding terrain, shape, slope, height, openings, and other features is essential.
For starters, one must consider the typical high wind speeds for the installation site. Consult your region's ASCE 7.95 Figure 6-1 Basic Wind Speed, or FM Approval Standard for Class 1 Exterior Wall Systems. In addition, the structural engineer must consider the natural forces on the building site; for example, is the building situated along water, mountains, or in an open field, and do tall trees or taller buildings surround it? Each of these factors can create a channeling force to intensify wind pressure against a structure.
Of course the building design itself is very important. Low rise buildings, generally regarded as 60 feet or lower, are less affected by a given wind load than buildings that are 60 feet and taller, which may experience substantial uplift forces in addition to direct/positive wind pressure.
Wind accelerates as it passes over a wall, causing a pressure differential and uplift, that is exerted on any living wall design. Redirected winds of this nature tend to whirl and swirl, and such forces are typically greatest at the edges of the wall but vary with building shape and height, overall exposure, size of openings, and other local factors.
How Much Uplift?
How much uplift force can a vertical garden wall tolerate? The weight, surface area of the vegetation and porosity of the soil are variable. The LiveWall system utilizes set screws and WindClips™ for wind challenged applications, and LiveWall is currently investigating wind tunnel testing options to quantify the degree of wind force that the LiveWall system can withstand. Please email us at firstname.lastname@example.org or call 877-554-4065 to discuss the wind lateral load conditions for your building site.
LiveWall Structure Code-Compliant on High-Wind Applications
In March 2016, UL LLC tested the LiveWall Structure according to TAS-202 "Criteria for Testing Impact and Nonimpact Resistant Building Envelope Components using Uniform Static Air Pressure," Section 1619 of the Florida Building Code. The structure passed the Uniform Static Air Pressure Test at exterior (positive) and interior (negative) design pressures of 105 PSF.
These findings provide designers, building owners and code officials with assurance that LiveWall systems are safe for use on tall buildings and in wind-prone regions. For example, a LiveWall system installed on a 500 foot tall building in Orlando, Florida would comply with building code requirements. The following calculated minimum design loads encompass inland (120 mph wind speed) and most coastal (150 mph wind speed) regions of North America.*
*LiveWall system is considered a sign attached to the wall of a building per section 29.4.2 of ASCE 7-10 “Minimum Design Loads for Buildings and Other Structures.” Calculated loads using maximum values per equation 30.3.1 for velocity pressure in Exposure C as referenced in Chapter 30 “Wind Loads for Components and Cladding” of ASCE 7-10.
Living Wall Fire Resistance
Like all vertical garden designs, LiveWall is a building facade system and is not designed to be fire resistant. The molded LiveWall planters, however, are rated at 780º F flashpoint and burn at 450º F. Tthe soil is relatively nonflammable, and the plant flammability varies by species. For example, if fleshy succulent plants are used, they will help deter some threats of fire. If grasses are used, to reduce their flashpoint they should not be allowed to dry out. Proper use of the LiveWall System keeps the WallTer wall planters properly saturated, helping to reduce the danger of plant fires.
Living Wall Irrigation Hookup
The LiveWall system comes with the RainRail™ mounting tracks, which serve as the irrigation conduits. LiveWall also packages the header piping, irrigation valves and fittings (each fitted with a 15 psi pressure regulator), a 150 micron debris filter, irrigation controller, and backflow preventer. This "irrigation infrastructure" is fed by the irrigation mainline and blow-out fitting in areas of cold winter, as installed by owner or contractor.