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' l l iF DESIGN CONSIDERATIONS
<br /> GENERAL PV(Solar Applications)
<br /> Proper roofing tern design and selection requires the • Please review GAF Solar Guidelines,available at www.gaf.com,
<br /> p, g sys gbefore installing a PV System on a GAF Guaranteed Roof.
<br /> consideration of many factors.Although GAF's expertise is in
<br /> materials manufacturing,and not in engineering,architecture,or Internal Temperature/Humidity
<br /> specialized roof consulting,we have decades of extensive experience Extremes in internal tern erature/lrumidi
<br /> in the practical aspects of roofing. P h'are most often
<br /> Our experience su ests that careful consideration of the following associated with cold storage/freezer buildings,swimming pool
<br /> g g facilities,dryingg kilns,food processing plants,paper/pulp mills,
<br /> will help provide a ndamentally sound basis for design and and smelting/blast furnace facilities.What makes these building
<br /> selection of EverGuard°single-ply roofing systems. applications unusual is that the pronounced difference in vapor
<br /> pressure between the building interior and the exterior can cause a
<br /> SUSTAINABLE DESIGN pronounced vapor flow through the roof assembly.This can result
<br /> in a significant build-up of condensation within the roof assembly,
<br /> ENERGY STAR®is a joint program of the U.S.Environmental and severe deterioration of both the roof assembly itself and the
<br /> Protection Agency and the U.S.Department of Energy.It is structural de&
<br /> designed to help our nation save energy and money,and to Relevant dmgn considerations include.
<br /> protect the environment through energy-efficient products and
<br /> practices.Energy-efficient choices can help building owners —Incorporation of a vapor retarder at deck level to control
<br /> save significantly on energy costs and greenhouse gas emissions, vapor flow into and through the roof assembly;
<br /> without sacrificing features,style,or comfort.ENERGY STAR®helps _Attention to a vapor-tight seal between the roof and side
<br /> consumers,contractors,architects,and property owners make more
<br /> knowledgeable,energy-efficient choices. walls/penetrations;
<br /> The LEED®(Leadership in Energy and Environmental Design) —Utilization of closed-cell foam insulation and stainless
<br /> Green Building Rating System is a voluntary standard for developing steel fasteners to minimize potential for condensation-related
<br /> high-performance,energy efficient sustainable buildings.The LEED degradation of the roof system;
<br /> Certification System is a program that awards building points for _Limitation of penetrations through the roof deck;
<br /> satisfying specified green-building criteria and requirements.
<br /> Green Globes®is a web-based program for green building guidance —Avoidance of roof system attachment that will puncture the
<br /> and certification that includes an onsite assessment by a third party vapor retarder,
<br /> and is an alternative to the LEED°rating system. —Cold/freezer storage.Refer to GAF'sA Guide to Cold Storage
<br /> GAF's EverGuard®TPO is the first to be certified by NSF Roof Systems Design,available at www.gaf.com,for further
<br /> International for the NSF/ANSI 347 SustainabilityAssessmentfor information.
<br /> Single-PI
<br /> y Roo ang Membranes.The Standard includes criteria
<br /> across the product life cycle from raw material extraction through
<br /> manufacturing,use,and end-of-life management.Go to www.nsf. Positive Internal Pressure
<br /> org for details. Positive internal pressure is most often associated with
<br /> GAF's EverGuard Extreme®TPO Roofing Membrane was engineered manufacturin dean-room facilities,mechanical air-handling
<br /> with energy efficiency and sustainability in mind.This high- rooms,aircraa�ttt hangars,distribution centers with multiple
<br /> performance,reflective roof membrane is also geared for solar overhead doors,and high-rise office/residential towers.In all these
<br /> roof installations.The increasing use of photovoltaics(PV)has instances,positive internal pressures can adversely act on the
<br /> highlighted the challenges faced by roofing membranes exposed underside of the roof system.
<br /> to concentrated heat,sunlight,and UV.GAF scientists have created Conditions where the positive internal pressure is constant,as in
<br /> a grade of TPO single-ply membrane that is built to handle the the case of clean-room facilities and high-rise towers,may cause
<br /> extreme demands that can be placed on roofing membranes. the roof system to billow u in a mechanically attached system,i.e.,
<br /> EverGuard Extreme°TPO uses proprietary stabilizers and UV form a mattress effect,and may reduce the overall uplift resistance
<br /> absorbers to achieve weathering performance far beyond current of the roofing system.
<br /> standards. This effect can cause attachment concerns with other types of roof
<br /> • EverGuard Extreme®TPO can be installed up to 10 years system.installations including adhered systems.Conditions where
<br /> prior to the installation of solar overburden. the positive internal pressure is applied suddenly,as in the case of
<br /> aircraft hangars and distribution centers,may cause failure of the
<br /> • Installation of overburden will not affect the membrane roofing system due to pressure impact.
<br /> performance or warranty/guarantee coverage of EverGuard Relevant design cons derations include.
<br /> Extreme TPO.
<br /> • Please contact GAF before installing any overburden on —Use of air-impermeable deck construction,such as
<br /> the roof. poured-in-place concrete or insulating cellular concrete over a
<br /> steel pan;
<br /> —Alternatively,installation of an air barrier,such as
<br /> BUILDING UTILIZATION polyethylene sheeting,at deck level beneath mechanically
<br /> Building utilization can have a significant impact on roofing attached insulation with attachment sufficient to balance
<br /> system selection and design.The most common building utilization positive pressure;
<br /> considerations are as follows:PV(solar applications),extremes in —Attention to an air-tight seal between roof and side walls/
<br /> internal temperature/humidity;positive internal pressure;rooftop penetrations.
<br /> traffic/abuse;rooftop-exhausted contaminants;and the use of the
<br /> roof as living space.
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