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RGGF DESIGN CONI1 'A 1 EXPANSION JOINTS WIND PERFORMANCE_ The function of a structural expansion joint is to minimize the Ideally,roofing systems should be capable of resisting the forces effect of stresses and movements on building components and to generated by the maximum anticipated wind speed for a specific prevent these stresses from adversely affecting the roof.The design, building.One widely accepted method for specifying wind location,and use of building structural expansion joints must performance is to require the appropriate FM 1-60,1-90,or other be considered at the time of original building design and are the rated system as appropriate for a specific building based upon responsibility of the architect,engineer,and building owner. location and exposure. Expansion Joints: The following are common references and approvals typically used —Must be continuous along the break in the structure and not in conjunction with the wind performance of EverGuard®roofing terminated short of the end of the roof deck. systems' —Should never be bridged with insulation. ®Factory Mutual Approvals —Construction ties must be removed in order for expansion joints —Testing based on methods described in Approval Standards to function properly. 4450 and 4470. —Extend expansion joints at least 8" (203 mm)above the roof —Measures resistance to upward pressure applied to the surface on curbs and use either EverGuard°Prefabricated roof system. Expansion Joint Covers or metal expansion joint covers. —Factory Mutual Loss Prevention Data Sheets 1-28 and 1-29 Alternately,a low-profile expansion joint can be used;see provide specific installation guidelines. EverGuard®details for construction. •DORA(Directory Of Roofing Assemblies) —Design drainage flow patterns so they are not blocked by any The Directory of Roof Assemblies(DORA)is a web application structural expansion joints. database of roof systems tested in accordance with standards —Where possible,position walkways on roof access points to limit referenced in Chapter 15 of the International Building Code roof traffic over expansion joints;provide protective coverings (IBC).This service lists wind uplift load capacity on single ply for expansion joints at locations of anticipated roof traffic. and modified bitumen roof systems. —All expansion joints should have wood nailers. —Listed in MasterSpec —EverGuard®Pre-Fab Expansion Joint Covers are available. —Sponsored by SPRI and administered by InterTek —Available at https://www.dora-directory.com/ AREA DIVIDERS ®American Society of Civil Engineers (ASCE)document ASCE 7,"Minimum Design Loads for Buildings and Area dividers are not structural expansion joints.They can Other Structures" be installed to separate different roofing systems and can be —A comprehensive analysis of wind forces acting on buildings. either a curb or low-profile type.Please call 800-766-3411 for recommendations regarding area dividers. —Requires detailed calculations to determine actual wind pressures at different regions of the roof. EQUIPMENT MOUNTINGS —Referenced by building codes.Check with local code agency as to the latest version that has been adopted. Proper mounting of equipment is an important consideration.In general,rooftop equipment should be mounted in such a way as to provide adequate flashing height for both new and anticipated GAF provides the following thermoplastic Perimeter Half Sheet Table re-cover roof system applications;sufficient clearance around and to use as a guide for mechanically attached systems because wind beneath the equipment to facilitate roof system installation;and pressures are increased in the corners and perimeter areas of the compatibility with roofing and flashing materials so that standard roof.The field area of the roof normally experiences significantly flashing methods can be readily applied. lower wind pressures than either the corner or perimeter areas. Alternatively,lightweight equipment and gas/conduit lines can be installed on wood blocking or other prefabricated devices that do not penetrate the roofing system.Do NOT use this type of application for heavy equipment or heavy gas/conduit lines,or where movement can damage the substrate or membrane. FIRE RESISTANCE Resistance by the roofing system to fire applied to the exterior roof surface is important.Typically,an ANSI/UL 790 or ASTM-E108 Class A,B or C roof fire rating is required by building code.Occasionally, depending on the use of the building,special resistance to fire applied from within the building is required.This is normally expressed in the form of hourly ratings,and usually requires the use of a specialized roof assembly.Refer to current EverGuard®listings in the appropriate UL directory or Factory Mutual Approval Listing to verify roof assembly requirements for specific fire ratings. 15