Preface

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1 RCABC Guarantee Corp. (RGC) Technical Committee

H. Schlamb Chilliwack Roofing Ltd. Chilliwack, BC RCABC Active Member (Contractor) G. Bollman GRC Columbia Roofing Inc. Chair Aldergrove, BC RCABC Active Member (Contractor) J. Bourget RDH Building Sciences Inc. Burnaby, BC RGC Accepted Observer S. Goldie Admiral Roofing Ltd. Prince George, BC RCABC Active Member (Contractor) J. Powers Flynn Canada Ltd. Kelowna, BC RCABC Active Member (Contractor) J. Wilson Top Line Roofing Ltd. Victoria, BC RCABC Active Member (Contractor) J. Klassen Roofing Contractors Association of British Columbia Non-voting Langley, BC RoofStar Technical Advisor A. Knoll Pacific Interior Roof Consulting & Inspection Ltd. Kelowna, BC RGC Accepted Observer S. Lang Inter-Provincial Roof Consultants Ltd. Langley, BC RGC Accepted Observer A. Martin Morrison Hershfield Ltd. Burnaby, BC RGC Accepted Observer L. Matzek Roofing Contractors Association of British Columbia Non-voting Langley, BC Director, RoofStar Guarantee Program J. Vanderkerkhove Parker Johnston Industries Ltd. Victoria, BC RCABC Active Member (Contractor) S. Wagner Atlas-Apex Roofing (BC) Ltd. Richmond, BC RCABC Active Member (Contractor) J. Watson J. Watson Roofing Consulting Inc. Victoria, BC RGC Accepted Observer D. Wells Roofing Contractors Association of British Columbia Non-voting Langley, BC RoofStar Technical Advisor

2 Revision History

This Manual was revised on February 5, 2021 and replaces the Manual dated October 30, 2020.

3 History of the Roofing Practices Manual

The RGC Roofing Practices Manual (RPM, or Manual) is the official collection of • published Standards necessary to design and build a Waterproofing or Water-shedding project intended to qualify for a RoofStar Guarantee. • listed materials formally accepted by the RCABC Guarantee Corporation (RGC), with which a project must be constructed to qualify for a RoofStar Guarantee. • information, technical standards and other resources intended to aid the Design Authority in specifying such a project. The RPM was first produced in 1988 by the RCABC Guarantee Corporation (RGC) Technical Committee, under the direction of the RGC Board of Directors. Its initial development was supported by representatives of the

       Architectural Institute of British Columbia (AIBC)
       Intergovernmental Roofing Advisory Group (IRAG)
       National Research Council (NRC)
       Roofing Inspectors and Consultants Association of British Columbia (RICABC)

Development of the RPM received its major impetus when the National Research Council, represented by its Industrial Research Assistance Program, provided financial assistance to the RCABC, so that a British Columbia Institute of Technology graduate could be hired to assist in the compilation of the very first Manual. Various extracts of information were authorized for reference by the

       Canadian Roofing Contractors Association (CRCA)
       National Roofing Contractors Association (NRCA)

and further valuable guidance was made available to the RCABC by the

       Alberta Roofing Contractors Association (ARCA)
       Roofing Industry Educational Institute (RIEI)

The completion of the 1988 Edition of the RPM initiated the development and subsequent expansion of the RCABC Guarantee for Workmanship and Materials, now called the RoofStar Guarantee Program. The RGC Roofing Practices Manual is an evolving document that is supported by RCABC Members, RGC Accepted Observers, the NRC, the British Columbia design community and other construction associations. It is revised and updated no fewer than three (3) times annually. Revisions to the RPM are published online (Technical Updates) and have been digitally updated since November 2010. Previous Technical Updates may be available from the Technical Department of the RCABC, upon written request.

4 Structure of the Roofing Practices Manual

The structure of the RPM has changed over time. Originally published as a paper-based binder with twelve tabs, it was digitized in 2012 and converted to an online wiki format. In 2016, the wiki-based RPM was restructured to form eight Divisions, A through H. Division A: Purpose, Scope, Use of the Manual and Standards Division A contains important information about the RPM and the RoofStar Guarantee Program, including any limitations and exclusions applicable to a RoofStar Guarantee. Division B: Essential Elements Division B is strictly informational in scope, divided by topics that support Standards but are not binding. Division C: Accepted Materials contains all the listed Accepted Materials used in the RoofStar Guarantee Program; it is searchable by a variety of methods, each made simple by ready hyperlinks. Division D: Standards for Roof Waterproofing Systems Division E: Standards for Water-shedding Systems Division F: Standards for Grade-level Waterproofing Systems Division G: Construction Details Division H: General Information Standards are located in Divisions D, E and F, and are distinguished by their function – roof waterproofing systems (Division D), water-shedding systems (Division E), and grade-level waterproofing systems (Division F). This "division by function" represents a departure from the traditional divisions (separating systems according to slope - "Low Slope Roofing", "Steep Slope Roofing" and "Waterproofing") and is a response to current design trends that increasingly utilize "flat" (waterproofing) roofs to support vegetation and amenity spaces, or to regulate storm-water discharge into public storm-water infrastructure, all of which may increase hydrostatic conditions on the roof. The revisions also allow for simplified language used in each Standard. Construction Details are in Division G, and are separated by system type. Each page of Construction Details is arranged to correspond to the Parts of a Standard, and each Construction Detail page contains explanatory notes that are hyperlinked back to the applicable Standard. General information, including references tables and the Glossary, can be found in Division H. Each Standard is prepared by the RCABC Guarantee Corp. (RGC) Technical Committee, under the final approval of the RCABC Guarantee Corp. (RGC) Board of Directors and is republished every four months. While printable versions of each Standard are available for download by users of the RPM, the online version remains the authoritative document in all respects.