State Of North Carolina

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Roofing CriteriaState of North CarolinaPat McCrory, GovernorDepartment of AdministrationKathryn Johnston, Acting SecretaryState Construction OfficeLatif Kaid, PE, Interim Director301 North Wilmington Street, Suite 450Raleigh, North Carolina 27601-2827(919)807-4100 Fax (919)807-4110www.nc-sco.comSecond EditionMarch 2016

Roofing DesignGuidelines and PoliciesROOFING DESIGNGUIDELINES AND POLICIESFOR LOW SLOPE ROOFSSTATE OF NORTH CAROLINADEPARTMENT OF ADMINISTRATIONSTATE CONSTRUCTION OFFICEFIRST EDITION – 1988SECOND EDITION – 2016Low Slope Membrane Roof 2016Page 2

Roofing DesignGuidelines and PoliciesPREFACEThis criteria for roofing design is a compilation of data, policies, legal aspects,preferences, experiences, prejudices, etc. that a Designer may find useful and necessaryin designing roofs and roofing systems and preparing contract documents relative toroofing of State owned buildings.This criteria is not a compendium of all roofing knowledge. It is not a State roofingspecification, not to be copied and printed or referenced in the Designer’s specifications.It is a tool of communication between the State Construction Office, the Designer and theUser Agency to make the process easier and the end result more successful. The Designeris to research the latest references, test data, product manuals, etc. and review the projectwith local roofing contractors and manufacturer’s representatives in evaluating theappropriate system to use.Contrary to a popular and belief, the State Construction Office does not have an“approved” list of roofing systems or manufacturers nor a “not approved” list. Any of theroofing systems and materials that are included in this criteria will provide a good soundroof when appropriately selected, designed and detailed by the Designer; when properlyinstalled by the Contractor, and properly maintained by the Owner. The Designer is hiredto evaluate all aspects of the building construction, function, site and budget, and to selectand prepare contract documents for a roofing system that will satisfy the designrequirements and reflect the latest in good roofing practice. State General Statutes requirethat the Designer name at least three acceptable manufacturers that can provide thespecified system.The State of North Carolina owns a wide variety of buildings that range from turkeybreeding barns to art and history museums, marine aquariums at the shore to magneticresonance imaging facilities at medical institutions; and lowland gorilla enclosures at thezoo to maximum security prisons. There are also different levels of maintenance providedat each facility. Many State owned building are unique buildings requiring well thoughtout selections for roofing systems and detailing.The State owns about 12,000 buildings. In a typical year the State Construction Officemay review between 200 to 300 projects that could roughly be divided into 1/3 newbuildings, or additions, 1/3 repair and renovation and 1/3 roofing replacement.Low Slope Membrane Roof 2016Page 3

Roofing DesignGuidelines and PoliciesTable of ContentsPREFACE . 3CHAPTER 1DEFINITIONS AND REFERENCES . 5CHAPTER 2GENERAL DESIGN . 9CHAPTER 3BASIC CRITERIA. 11CHAPTER 4ROOFING SELECTIONS . 34CHAPTER 5NEW ROOF CONSTRUCTION . 40CHAPTER 6ROOFING REPLACEMENT . 43CHAPTER 7GREEN ROOF. 48CHAPTER 9WARRANTY . 57CHAPTER 10SUSTAINABILITY . 60APPENDIX A . 63APPENDIX B . 64APPENDIX C . 66APPENDIX D . 67INDEX . 70Low Slope Membrane Roof 2016Page 4

Roofing DesignGuidelines and PoliciesCHAPTER 1DEFINITIONS AND REFERENCES1. General:This document made numerous references to The North Carolina State BuildingCode.” This code, for the purpose of this document, shall be known as the “Code.”The North Carolina State Building Code comprises seven (7) technical codes but onlyfive (5) are pertinent to this document, North Carolina State Building Code; BuildingCode; Plumbing Code; Fire Prevention Code and Energy Conservation Code; NorthCarolina Existing Building Code.2. Definitions:The two (2) dictionaries used to define the terms are the “Webster Dictionary” latestedition and the “Dictionary of Architecture and Construction” 4th Edition by McGrawHill. Other definitions not in the dictionaries are from NCSBC, NRCA andSMACNA.A. Control Joint: A joint placed within a roof system to relieve stresses betweenadjacent systems which does no directly correlate to an expansion joint inprimary building framing.B. Expansion Joint: A joint placed within a roof system to relieve structuralstresses between adjacent structural framing which aligns with or otherwisecorrelates to and continues a break in the structural framing system and othercomponents of the structural.C. Overburden: All items placed on the roof after a waterproofing membrane iscompleted on a green roof such as engineered soil, insulation, pavers etc.D. Overflow: Design method by which water is discharged from the roof when theprimary roof drainage systems is not functioning or blocked.E. Roof: According to “Webster Dictionary” is the outside top covering of abuilding or structure that protects, shelters or guards.” For the purpose of thiscriteria, according to “Dictionary of Architecture and Construction” 4th Editionby McGraw Hill,” the top covering of a building, including all materials andconstructions necessary to support it on the walls of the building or uprights;provides protection against rain, snow, sunlight, extremes of temperature andwind.F.Roof Deck: Can be of any construction material including wood, metal deckingand concrete. It is the flat or sloped surface not including its supporting membersLow Slope Membrane Roof 2016Page 5

Roofing DesignGuidelines and Policiesor vertical supports. The deck supports the non-load bearing components such asinsulation, membrane, flashing etc.G. Roof Drain: A drain designed to receive water collecting on the surface of a roofand to discharge it into a leader or a downspout.H. Roof Drainage System: On the roof of a building, a system composed of stormwater collection devices, and piping connected to these collection devices;transports the rainwater off the roof, out and away from the building.I.Roofing: Any material (or combination of materials) used as a roof covering,such as membrane, corrugated metal, sheet metal, shingles, slate, thatch, tiles andmembrane; usually provides waterproofing and wind protection.J.Roof Recover: The process of installing an additional roof covering over aprepared existing roof covering without removing the existing roof covering – asdefined in NCSBC.K. Roof Repair: Reconstruction or renewal of any part of an existing roof for thepurposes of its maintenance.L. Roof Replacement: The process of removing the existing roof covering,repairing any damaged substrate and installing a new roof covering.M. Scupper: A means of drainage consisting of an opening through a wall/parapetlined with sheet metal to allow the passage of water.N. Vapor Retarder: An impervious membrane placed in the roof system to retardor prevent the passage of water vapor.O. Vegetated Roof Assembly: A waterproofed substrate with plantings/landscapinginstalled above.3. References:The references listed publications/entity are basic essentials to proper design anddetailing of a roof.A. State Construction Office (SCO)North Carolina State Construction Manual301 N. Wilmington Street, Suite 450Raleigh, NC 27601-1058Phone Number: (919) 807-4100Fax: (919) 807-4110Web Site. http://www.nc-sco.comLow Slope Membrane Roof 2016Page 6

Roofing DesignGuidelines and PoliciesB. State Construction Office (SCO)North Carolina State Building Code: Building CodeNorth Carolina State Building Code: Existing Building CodeNorth Carolina State Building Code: Mechanical CodeNorth Carolina State Building Code: Plumbing CodeNorth Carolina State Building Code: Fuel Gas CodeNorth Carolina State Building Code: Fire Prevention CodeNorth Carolina State Building Code: Energy Conservation Code301 N. Wilmington Street, Suite 450Raleigh, NC 27601-1058Phone Number: (919) 807-4100Fax: (919) 807-4110Web Site. FGC)(NCFPC)(NCECC)C. North Carolina General Assembly (NCGA)North Carolina General Statute atutes.aspD. National roofing Contractors Association (NRCA)National Roofing Contractors Association Roofing Manual; Membrane RoofSystemGreen Roof Systems Manual10255 W. Higgins Road, Suite 600Rosemount, IL 60018-5607Phone Number: (847) 299-9070Fax: (847) 299-1186Website. http://www.nrca.netE. Sheet Metal and Air-Conditioning Contractor’s National Association, Inc.(SMACNA)4201 Lafayette Center DriveChantilly, VA 20151-1209Phone Number: (703) 803-2980Fax: (703) 803-3732Website. https://www.smacna.org/F.Underwriter’s Laboratory (UL)2600 N.W. Lake RoadCamas, WA 98607-8542Phone Number: (877) 854-2577Fax: (360) 817-6278Website: http://www.ul.com/global/eng/pages/G. Factory Mutual Global (FM)Presto Ridge III3460 Preston Ridge Road, Suite 400Low Slope Membrane Roof 2016Page 7

Roofing DesignGuidelines and PoliciesAlpharetta, GA 30005Phone Number: (770) 777-3600Fax: (770) 777-0414Website http://www.fmglobal.comH. American Society of Heating, Refrigerating and Air-Conditioning Engineers(ASHRAE 90.1)36588 Treasure CenterChicago, IL 60694-6500Phone Number: (800) 527-4723Website ngle Ply Roofing Institute (SPRI)465 Waverly Oaks Road, Suite 421Waltham, MA 04252Phone Number: (781) 647-7026Fax: (781) 647-7222Website http://www.spri.orgJ.Roof Consultants Institute (RCI)1500 Sunday Drive, Suite 204,Raleigh, NC. 27607Phone Number: (800) 828-1903Fax: (919) 859-0742Website http://www.rci-online.orgK. NSF InternationalP.O. Box 130140789 N. Dixboro RoadAnn Arbor, MI. 48105http://www.nsf.org/Low Slope Membrane Roof 2016Page 8

Roofing DesignGuidelines and PoliciesCHAPTER 2GENERAL DESIGN1. PurposeThe purpose of this manual is to establish a minimum design standard for facilitiesowned by the State of North Carolina. This document is not intended to be a Stateroofing specification or a summary of the North Carolina State Building Code or theauthority on low slope membrane roofing. Designer is solely responsible for ensuringcompliance with all applicable codes and standards.2. Designer ResponsibilityA. State projects involving roofing shall use and follow the Department ofAdministration document “Roofing Design Guidelines and Policies” only for thepurpose of preparing the designer’s plans and specifications for their specificproject. This document is not written in contractual language for biddingpurposes and/or contractual enforcement and is NOT to be inserted into thespecification.B. It is the Designer’s responsibility to be well versed with all relevant criteria in theState Construction Office “Roofing Design Guidelines and Policies.” This andother guidelines are available on the State Construction Office website.C. If the roofing project is a ‘stand-alone’ project, review the State ConstructionOffice Manual for documentation and bidding requirements.D. Modified version of the Building Code Summary, Appendix B, For AllCommercial Roof Projects – this document is intended to summarize theminimum requirement by State Construction Office for roofing projects on StateOwned facilities. It does not modify the requirements of the Building Code. Thedesigner of record is responsible to ensure all roofing projects conform to theminimum requirement of the Code.E. Design Calculations – The Designer is record is responsible for performing allnecessary design calculations to ensure compliance with the Code. Calculationsshould be sealed by a licensed Engineer in the State of North Carolina andmaintain in the Designer’s project files. Design calculations should include:a. Dead Loadb. Wind Uplift Pressuresc. Primary Drainaged. Secondary (Emergency Overflow) Drainagee. R-valuef.Dew Point AnalysisLow Slope Membrane Roof 2016Page 9

Roofing DesignGuidelines and Policies3. Protection and SafetyA. The majority of roofing projects occur on occupied existing building, theDesigner shall explore components and systems not only from a performancestandpoint but also for life safety.B. Consideration should be given to the inventory of the building, and incorporatecomponents and system as necessary to protect those contents. This is especiallytrue with laboratories, storage/warehouse etc.4. System Selectionroofing system should be selected based on the intended use of the facility. Designersshould consult with State building Owner/Users to determine the specifics of thefacility that affect roof system selection (anticipated future use, service, life rooftopequipment, etc.)5. EnergyA. The minimum roof insulation shall meet the requirements of the North CarolinaState E