UseRainscreen cladding system for multistory buildings in high-velocity hurricane zones
CharacteristicsWeatherproof, energy efficient, fire-retardant and impervious to hurricane-force winds and debris
|Project:||Rainscreen cladding system for multistory buildings in high-velocity hurricane zones|
|Location:||Tested at ATI test lab in Atlanta; listed for use in Florida; suitable for costal hurricane zones from the Gulf of Mexico to the Eastern Seaboard|
|Fabricator/Installer:||System design jointly developed by ALPOLIC, Rmax and Altech|
|Exterior Panel Manufacturer:||ALPOLIC|
|Products:||R-TRAC HVHZ Pressure Equalized Rainscreen System, comprising ALPOLIC® ACM and MCM materials, Rmax foil-faced polyisocyanurate (polyiso) insulation sheathing, and Altech mounting system|
|Completion:||Florida approval FL16406 granted September 9, 2013|
With stricter building codes for performance and safety, architects face a real challenge making building exteriors weatherproof, energy efficient, fire-retardant and impervious to hurricane-force winds and debris. ALPOLIC has teamed with Rmax and Altech to provide a rainscreen cladding system that does it all – easily and affordably.
In high-velocity hurricane area, a building envelope needs to meet three criteria:
- It must comply with continuous insulation (CI) requirements specified by the 2012 ICC International Energy Conservation Code for the appropriate climate zone.
- It must pass NFPA 285 fire testing, required for multistory exterior non-load-bearing wall assemblies
- It must withstand the appropriate wind loading and missile impact standards for high-velocity hurricane zones – for example, the Testing Application Standards (201, 202, and 203) of the 2010 Florida Building Code and the windborne debris and missile impact standards of ASTM E1886 and E1996
ALPOLIC collaborated with Rmax and Altech Panel Systems to create the first pressure-equalized rainscreen system using composite panels that satisfies all three criteria for multistory applications in hurricane zones.
Through innovative engineering, they replaced three traditional multistory firewall components – Type X gypsum board, insulation, and a water barrier system – with a single structural/insulation component from Rmax, a simplification that met all regulations and is even more affordable.
Standing up to Hurricane-Force Winds
Rmax foil-faced polyiso product provides continuous insulation, water barrier and fire resistance needed, but it required tests to see whether it could withstand hurricane-force winds. To achieve high-velocity hurricane zone ratings, materials must be able to withstand wind loads of up to 180 psf.
The Rmax held even beyond the point where the steel studs it was mounted to buckled – a resounding success. Based on these tests, a specification table was created to help customers choose the right configuration for their wind-load requirements without overpaying for unnecessary fasteners.
Standing up to Forceful Impacts and Fire
With the necessary continuous insulation and wind-loading requirements met, the panels had to fulfil NFPA 285 test protocol to determine the fire performance of combustible material in noncombustible exterior wall systems.
ASTM E1886 and E1996 require testing the wall for resistance to hurricane-force impacts from objects ranging in size and mass from roof gravel to tree limbs. This involves shooting missiles as large as 2x4s from a special high-velocity cannon in an attempt to penetrate the ALPOLIC panels. These missile shots are followed by cycles of high positive and negative pressure. The assembly must survive with limited deformation or deflection.
The R-TRAC HVHZ Pressure Equalized Rainscreen System easily passed the fire and impact tests, and received Florida certification on September 9, 2013.