(Draft) PVC Roof Systems Standard - Revision history

James Klassen at 15:33, 23 September 2026

2026-09-23T15:33:35Z

Show changes

James Klassen at 21:35, 22 September 2026

2026-09-22T21:35:57Z

James Klassen at 14:36, 6 August 2026

2026-08-06T14:36:47Z

James Klassen: /* 13.1.3.4. Gauge, Dimension Limitations, and Seams */

2026-08-06T14:22:36Z

‎13.1.3.4. Gauge, Dimension Limitations, and Seams

James Klassen: /* 9.2.1.1. Membrane Composition, Thickness, and Selection */

2026-06-26T21:05:21Z

‎9.2.1.1. Membrane Composition, Thickness, and Selection

James Klassen: /* 2.1.1.2. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }} */

2026-06-24T21:11:32Z

‎2.1.1.2. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }}

James Klassen at 15:05, 22 June 2026

2026-06-22T15:05:59Z

Show changes

James Klassen: /* 1.1.1.4. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }} */

2026-06-22T14:35:27Z

‎1.1.1.4. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }}

James Klassen: /* 1.1.1.4. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }} */

2026-06-22T14:31:13Z

‎1.1.1.4. {{strike| Definitions || 2024-October-23 }}{{hilite | Defined Terms || 2025-October-25 }}

James Klassen: /* 11.1.3.2. Roof Drain Function and Location */

2026-05-11T14:37:39Z

‎11.1.3.2. Roof Drain Function and Location

@@ Line 607: / Line 607: @@
 <ol>
 <li>strip-in flashings for roof penetrations (Ref. [[#Part 12 - Penetrations and Curbs | Part 12]]),
-<li>roof drains (cast-iron roof drains in usable condition are exempted from this requirement; see [[#11.3.3.2. General Requirements for Cast-iron Roof Drains | Article 11.3.3.2.]]), and
+<li>roof drains (cast iron roof drains in usable condition are exempted from this requirement; see [[#11.3.3.2. General Requirements for Cast Iron Roof Drains | Article 11.3.3.2.]]), and
 <li>''linear metal flashings'' (Ref. [[#Part 13 - Linear Metal Flashing | Part 13]]).
 </li></ol>
@@ Line 4,222: / Line 4,222: @@
 <li><span class="principles">If a flow {{hilite | control || 2025-October-25 }} {{strike| restrictor || 2024-October-29 }} is present in an existing cast drain leader, the {{hilite | flow control || 2025-October-25 }} {{strike| restrictor || 2024-October-29 }} should be reinstalled</span>.
 <li>Roofs that support ''overburden'', and roofs that are secured with ballast, must be designed to incorporate a ballast guard that surrounds the drain and promotes proper drainage.
-<li>{{hilite | Roofs designed to support a ''vegetated roof system'' covered by a '''''RoofStar Vegetated Roof Guarantee''''' must design the drainage system, including ''roof drain'' protection measures, in coordination with the “RGC Standard for Vegetated Roofs” (Note that if an existing roof incorporates flow control drains , reinstating them as part of a roof replacement ''project'' may adversely affect the viability a ''vegetated roof system'', thereby necessitating a wider redesign of roof drainage.)(See|| 2025-October-25 }} [https://rpm.rcabc.org/index.php?title=VRA_Standard#1.1.3.2._Permitted_Vegetated_Roof_Systems {{hilite | Sentence  1.1.3.2.(9)|| 2025-October-25 }}], {{hilite | “RGC Standard for Vegetated Roofs”; also see|| 2025-October-25 }} [[#11.3.3.2. General Requirements for Cast-iron Roof Drains | {{hilite | Article 11.3.3.2.]])|| 2025-October-25 }}.
+<li>{{hilite | Roofs designed to support a ''vegetated roof system'' covered by a '''''RoofStar Vegetated Roof Guarantee''''' must design the drainage system, including ''roof drain'' protection measures, in coordination with the “RGC Standard for Vegetated Roofs” (Note that if an existing roof incorporates flow control drains , reinstating them as part of a roof replacement ''project'' may adversely affect the viability a ''vegetated roof system'', thereby necessitating a wider redesign of roof drainage.)(See|| 2025-October-25 }} [https://rpm.rcabc.org/index.php?title=VRA_Standard#1.1.3.2._Permitted_Vegetated_Roof_Systems {{hilite | Sentence  1.1.3.2.(9)|| 2025-October-25 }}], {{hilite | “RGC Standard for Vegetated Roofs”; also see|| 2025-October-25 }} [[#11.3.3.2. General Requirements for Cast Iron Roof Drains | {{hilite | Article 11.3.3.2.]])|| 2025-October-25 }}.
 </li></ol>
@@ Line 4,245: / Line 4,245: @@
 (The requirements for [[#11.1.3. All Systems | Subsection 11.1.3., "All Systems"]], shall be read together with the following Articles)
-====11.1.4.1. Cast-iron Roof Drains====
+====11.1.4.1. Cast Iron Roof Drains====
 <ol>
-<li>Only cast-iron roof drains, and existing external couplers used to connect drains to leaders, may be re-used for roof replacement ''projects''.
+<li>Only cast iron roof drains, and existing external couplers used to connect drains to leaders, may be re-used for roof replacement ''projects''.
-<li><span class="principles">Drain extensions for cast-iron roof drains should be avoided, since the connection with the cast drain is not sealed; the result is a leak into the ''roof system''</span>.
+<li><span class="principles">Drain extensions for cast iron roof drains should be avoided, since the connection with the cast drain is not sealed; the result is a leak into the ''roof system''</span>.
 </li></ol>
@@ Line 4,332: / Line 4,332: @@
 <ol>
-<li>{{hilite | Except for cast-iron roof drains, which are usually supplied and installed by others, only new drains and penetration flashings listed in [[Division_C | Division C]] may be used.
+<li>{{hilite | Except for cast iron roof drains, which are usually supplied and installed by others, only new drains and penetration flashings listed in [[Division_C | Division C]] may be used.
 <li>{{hilite | All roof drains and overflows must conform to CSA ASME A112.6.4-2022/CSA B79.4-2022, "Roof, deck, and balcony drains", unless otherwise permitted by the '''''Guarantor'''''|| 2026-July-1 }}.
 <li>Reuse of any penetration flashing or drain (except serviceable cast iron drains) is prohibited and may void the ''Guarantee'' (See Division A, [[Guarantee#3.2.1.2._Limitations_and_Exclusions_of_Guarantee | Article 3.2.1.2.]])|| 2021-February-5 }}.
@@ Line 4,348: / Line 4,348: @@
 <li>shall be made so that the roof membrane can be sealed to the drain body or bowl (the membrane seal must not rely solely on a clamping ring).
 </li></ol>
-<li>Cast-iron ''primary roof drains''
+<li>Cast iron ''primary roof drains''
 <ol>
 <li>must be supplied with a sump receiver and under-deck clamp,
@@ Line 4,354: / Line 4,354: @@
 <li>{{hilite | must be installed by the trade supplying the roof drain. || 2023-June-16 }}
 </li></ol>
-<li>{{hilite | Cast-iron planter drains must be supplied with a perforated riser that is proprietary to the drain manufacturer (See the “RGC Standard for Vegetated Roofs”,|| 2025-October-25 }} [https://rpm.rcabc.org/index.php?title=VRA_Standard#6.1.3.2._Planter_Drainage{{hilite | Article 6.1.3.2|| 2025-October-25 }}]).
+<li>{{hilite | Cast iron planter drains must be supplied with a perforated riser that is proprietary to the drain manufacturer (See the “RGC Standard for Vegetated Roofs”,|| 2025-October-25 }} [https://rpm.rcabc.org/index.php?title=VRA_Standard#6.1.3.2._Planter_Drainage{{hilite | Article 6.1.3.2|| 2025-October-25 }}]).
-<li>{{hilite | Cast-iron ''scupper drains'' must be || 2023-June-16 }}
+<li>{{hilite | Cast iron ''scupper drains'' must be || 2023-June-16 }}
 <ol>
 <li>{{hilite | supplied with a clamping strainer, || 2023-June-16 }} and
@@ Line 4,533: / Line 4,533: @@
 </li></ol>
-====11.3.3.2. General Requirements for Cast-iron Roof Drains====
+====11.3.3.2. General Requirements for Cast Iron Roof Drains====
 <ol>
-<li>Cast-iron roof drains must be installed by the plumbing/mechanical trade.
+<li>Cast iron roof drains must be installed by the plumbing/mechanical trade.
-<li>When cast-iron roof drains are used, a sump receiver and under-deck clamp must be provided and installed by the trade supplying the roof drain.
+<li>When cast iron roof drains are used, a sump receiver and under-deck clamp must be provided and installed by the trade supplying the roof drain.
-<li><span class="principles">Drain extensions for cast-iron roof drains should be avoided</span>.
+<li><span class="principles">Drain extensions for cast iron roof drains should be avoided</span>.
 <li><span class="principles">Existing flow {{hilite | control {{strike| restrictors || 2024-October-29 }} || 2025-October-25 }} removed during roof construction should be reinstalled</span>; {{hilite | however, if the replacement roof will support a ''vegetated roof system'', the drainage design must conform to the requirements set out by the '' Design Authority'' || 2025-October-25 }}.
-<li>All cast-iron roof drains must be
+<li>All cast iron roof drains must be
 <ol>
 <li>new or clean,
@@ Line 4,549: / Line 4,549: @@
 </li></ol>
-====11.3.3.3. Cast-iron Drains Installed with Continuous Field Membrane====
+====11.3.3.3. Cast Iron Drains Installed with Continuous Field Membrane====
 <ol>
@@ Line 4,569: / Line 4,569: @@
 </li></ol>
-====11.3.3.4. Cast-iron Drains Installed with Membrane Flashing====
+====11.3.3.4. Cast Iron Drains Installed with Membrane Flashing====
 <ol>
@@ Line 4,591: / Line 4,591: @@
 </li></ol>
-====11.3.3.5. Cast-iron Roof Drain Retrofitting (Replacement Roofing)====
+====11.3.3.5. Cast Iron Roof Drain Retrofitting (Replacement Roofing)====
 <ol>
-<li><span class="recommended">Retrofitting a cast-iron roof drain is not recommended</span>, but when retrofitting is unavoidable (i.e., the drain has deteriorated to the extent that it cannot receive a new roof membrane, and removal is not possible),
+<li><span class="recommended">Retrofitting a cast iron roof drain is not recommended</span>, but when retrofitting is unavoidable (i.e., the drain has deteriorated to the extent that it cannot receive a new roof membrane, and removal is not possible),
 <ol>
 <li>remove any broken parts and debris,
 <li>connect the retrofit insert to internal leaders using only an external coupling (unless impractical - see alternative requirements below), and
-<li>follow the requirements set out in [[#11.3.3.2. General Requirements for Cast-iron Roof Drains | Article 11.3.3.2.]]
+<li>follow the requirements set out in [[#11.3.3.2. General Requirements for Cast Iron Roof Drains | Article 11.3.3.2.]]
 </li></ol>
 <li>When an internal compression seal is used out of necessity to connect a retrofit drain to an existing drain leader,

@@ Line 3,790: / Line 3,790: @@
 <li>{{hilite |When sheet membrane flashing is terminated on a vertical surface, it must be secured at its upper termination using|| 2021-October-30 }}
 <ol>
-<li>{{hilite | '''Option 1''' ({{hilite | '''Figure 10.3.2.3.-A''' || 2025-October-25 }}), in which the upper edges of fully adhered sheet membrane flashing plies shall be protected and secured with overlapping adhered or self-adhered ''wall'' membranes and exterior sheathing|| 2021-October-30 }},
+<li>{{hilite | '''Option 1''' ({{hilite | '''Figure 10.3.2.3.-A''' || 2025-October-25 }}), in which the upper edges of fully adhered sheet membrane flashing plies shall be protected and secured with overlapping adhered or self-adhered ''wall'' membranes and exterior cladding|| 2021-October-30 }},
 <li>'''Option 2''' ({{hilite | '''Figure 10.3.2.3.-B''' || 2025-October-25 }}), where the upper edges of fully adhered sheet membrane flashing plies must be {{hilite |sealed, and mechanically secured to the wall substrate, with a RoofStar-accepted reinforced liquid membrane flashing (Ref. [[#10.3.3.4. Liquid Membrane Flashing | Article 10.3.3.4., "Liquid Membrane Flashing"]])|| 2021-October-30 }},
 <li>{{hilite | '''Option 3''' ({{hilite | '''Figure 10.3.2.3.-C''' || 2025-October-25 }}), where|| 2021-October-30 }}
@@ Line 5,687: / Line 5,687: @@
 <li>{{hilite | into or through plywood so that screw threads engage its full thickness, excluding the unthreaded tip, and || 2024-January-31 }}
 <li>{{hilite | into solid substrate (i.e., dimensional lumber or concrete) at least 25.4 mm (1"), and || 2024-January-31 }}
 <li>must be installed at least 88.9 mm (3-1/2") above the ''finished system surface''.
 </li></ol>
 {{strike| <li>Where hidden metal clips are required, they must

@@ Line 5,416: / Line 5,416: @@
 |  22+ || Butt Seams*
 |-
-|  rowspan="2" style="vertical-align:centre;text-align:center;"   | {{hilite | Up to 304.8 mm (12") || 2026-October-31 }} || rowspan="2" style="vertical-align:centre;text-align:center;"   | {{hilite | 2% || 2026-October-31 }} || 24 || rowspan="6" style="vertical-align:centre;text-align:center;"   | {{hilite | 3048 mm (12"),<br>as specified by a<br>''registered professional'' || 2026-October-31 }} || {{hilite | S-lock or Standing Seam<sup>†</sup> || 2026-October-31 }}
+|  rowspan="2" style="vertical-align:centre;text-align:center;"   | {{hilite | Up to 304.8 mm (12") || 2026-October-31 }} || rowspan="2" style="vertical-align:centre;text-align:center;"   | {{hilite | 2% || 2026-October-31 }} || 24 || rowspan="6" style="vertical-align:centre;text-align:center;"   | {{hilite | 3048 mm (120"),<br>as specified by a<br>''registered professional'' || 2026-October-31 }} || {{hilite | S-lock or Standing Seam<sup>†</sup> || 2026-October-31 }}
 |-
 |  22+ || {{hilite | Butt Seams* || 2026-October-31 }}

@@ Line 3,081: / Line 3,081: @@
 |              rowspan="4" style="text-align:left;background-color:#4682B4"        |              <span style="color:#fff">PVC</span>
 |-
-|              rowspan="1" style="text-align:center;background-color:#FFA07A"             |    5             ||      rowspan="1" style="text-align:center;width=200px;"             |          1.270 (50)          ||    rowspan="1" style="text-align:center;width=200px;"             |       <span style="color:#d33">X</span>           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.270 (50)           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.270 (50)           ||  rowspan="1" style="text-align:center;width=200px;"             |         1.524 (60)        ||     rowspan="1" style="text-align:center;width=200px;"             |      1.270 (50)       || rowspan="1" style="text-align:center;width=200px;"             |       1.270 (50)         ||  rowspan="1" style="text-align:center;width=200px;"             |     1.524 (60)
+|              rowspan="1" style="text-align:center;background-color:#FFA07A"             |    5             ||      rowspan="1" style="text-align:center;width=200px;"             |          1.270 (50)          ||    rowspan="1" style="text-align:center;width=200px;"             |       <span style="color:#d33">X</span>           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.270 (50)           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.270 (50)           ||  rowspan="1" style="text-align:center;width=200px;"             |         1.524 (60)        ||     rowspan="1" style="text-align:center;width=200px;"             |      1.270 (50)       || rowspan="1" style="text-align:center;width=200px;"             |       1.270 (50)         ||  rowspan="1" style="text-align:center;width=200px;"             |     <span style="color:#d33">X</span>
 |-
-|              rowspan="1" style="text-align:center;background-color:#E9967A"            |    10           ||      rowspan="1" style="text-align:center;width=200px;"             |          1.524 (60)         ||    rowspan="1" style="text-align:center;width=200px;"             |       <span style="color:#d33">X</span>           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.524 (60)          ||   rowspan="1" style="text-align:center;width=200px;"             |        1.524 (60)            ||  rowspan="1" style="text-align:center;width=200px;"             |         1.524 (60)         ||     rowspan="1" style="text-align:center;width=200px;"             |      1.524 (60)       || rowspan="1" style="text-align:center;width=200px;"             |       1.524 (60)         ||  rowspan="1" style="text-align:center;width=200px;"             |    1.524 (60)
+|              rowspan="1" style="text-align:center;background-color:#E9967A"            |    10           ||      rowspan="1" style="text-align:center;width=200px;"             |          1.524 (60)         ||    rowspan="1" style="text-align:center;width=200px;"             |       <span style="color:#d33">X</span>           ||   rowspan="1" style="text-align:center;width=200px;"             |        1.524 (60)          ||   rowspan="1" style="text-align:center;width=200px;"             |        1.524 (60)            ||  rowspan="1" style="text-align:center;width=200px;"             |         1.524 (60)         ||     rowspan="1" style="text-align:center;width=200px;"             |      1.524 (60)       || rowspan="1" style="text-align:center;width=200px;"             |       1.524 (60)         ||  rowspan="1" style="text-align:center;width=200px;"             |    <span style="color:#d33">X</span>
 |-
 |              rowspan="1" style="text-align:center;background-color:#FA8072"             |    15           ||      rowspan="1" style="text-align:center;width=200px;"             |         <span style="color:#d33">X</span>           ||    rowspan="1" style="text-align:center;width=200px;"             |       <span style="color:#d33">X</span>            ||   rowspan="1" style="text-align:center;width=200px;"             |        2.032 (80)           ||   rowspan="1" style="text-align:center;width=200px;"             |        2.032 (80)           ||  rowspan="1" style="text-align:center;width=200px;"             |        2.032 (80)         ||     rowspan="1" style="text-align:center;width=200px;"             |      <span style="color:#d33">X</span>        || rowspan="1" style="text-align:center;width=200px;"             |       2.032 (80)         ||  rowspan="1" style="text-align:center;width=200px;"             |     <span style="color:#d33">X</span>

@@ Line 659: / Line 659: @@
 <li>Words that appear in italics are defined in the [[Glossary | Glossary]].  Additionally, the following terms are used in this Part:
 <ol>
-<li>''Common Slope'' means a roof with a slope 1:3 (4” in 12”, or 18 degrees), up to and including 1:1 (12” in 12”, or 45 degrees).
+<li>''Common Slope'' means a slope 1:3 (4” in 12”, or 18 degrees), up to and including 1:1 (12” in 12”, or 45 degrees).
 <li>{{hilite | ''Deck overlay''|| 2021-June-30 }} {{hilite | means a panel material secured to the ''supporting deck'', to render the deck surface suitable for the installation of roofing materials|| 2021-June-30 }}.
-<li>''Extreme Slope'' means a roof with a slope <u>greater than</u> 21:12 (21” in 12”, or 84 degrees).
+<li>''Extreme Slope'' means a slope <u>greater than</u> 21:12 (21” in 12”, or 84 degrees).
-<li>''Flat'' (roof) means a roof with a slope less than 1:6 (2” in 12”, or 9 degrees).
+<li>''Flat'' means a slope less than 1:6 (2” in 12”, or 9 degrees).
 <li>''Low Slope'' means a roof with a slope 1:6 (2" in 12", or 9 degrees, up to but less than 1:3 (4” in 12”, or 18 degrees).
 <li>{{hilite | ''Sheathing'' means a rigid panel material secured directly onto framing. || 2024-January-31 }}
-<li>''Steep Slope'' means a roof with a slope <u>greater than</u> 1:1 (12” in 12”, or 45 degrees) up to and including 21:12 (21” in 12”, or 84 degrees).
+<li>''Steep Slope'' means a slope <u>greater than</u> 1:1 (12” in 12”, or 45 degrees) up to and including 21:12 (21” in 12”, or 84 degrees).
 <li>{{hilite | ''Supporting deck'' ("deck")|| 2021-June-30 }} {{hilite | means the "structural surface to which a ''roof system'' is applied" (adapted from ''ASTM D1079-18 Standard Terminology Relating to Roofing and Waterproofing'')|| 2021-June-30 }}.
 <li>{{hilite | ''Wall''|| 2021-June-30 }} {{hilite | means a structural or non-structural element in a building that vertically separates space.  ''Walls'' may separate the outside environment from the interior conditioned space of a building, or they may separate one or more interior spaces from each other (adapted from ASTM E631-15, "Standard Terminology of Building Constructions")|| 2021-June-30 }}.

@@ Line 124: / Line 124: @@
 {{strike| {{hilite |''Finished roof system surface''|| 2020-February-3 }} {{hilite | means the top surface of any ''roof system'', inclusive of ballast or ''overburden''|| 2021-February-7 }}. || 2026-June-11 }}
 <li>''Grade-level waterproofing system'' means an insulated or uninsulated ''system'', designed and constructed at grade with a sheet or liquid-applied membrane, to exclude water.
 <li>{{hilite | ''Linear metal flashing'' means flashings cut and shaped from flat metal stock, to redirect water at roof perimeters and edges, or to control the flow of water in valleys and drainage spillways.  ''Linear metal flashings'' also protect roof membranes from weathering and damage and provide an aesthetic finish to the ''waterproofing system''  or ''water-shedding system''|| 2027-June-11 }}.
 {{strike| {{hilite | ''Linear metal flashing''|| 2021-June-30 }} {{hilite | means flashings cut and shaped from flat metal stock, to redirect water at roof perimeters and edges, or to control the flow of water in valleys and drainage spillways.  ''Linear metal flashings'' also protect roof membranes from weathering and damage and provide an aesthetic finish to the ''roof system''|| 2021-June-30 }}.|| 2026-June-11 }}
 <li>{{hilite | ''Membrane system'' means the combination of field and flashing membranes which function together to waterproof underlying materials and ''systems''. || 2023-June-16 }}
 <li>{{hilite | ''Observer'' means a firm or person paid by the building Owner (directly, or through the '''''RGC'''''), who is independent (not a member) of the RCABC, and who is accepted by the '''''RGC''''' to provide Quality Assurance reviews during construction and after completion of the ''project'', according to the terms and conditions set out in RCABC policy || 2025-October-25 }}.

@@ Line 121: / Line 121: @@
 <ol>
 <li>''Design Authority'' means the individual or firm responsible for the issuance of ''project'' specifications and details to which the ''project'' will be bid and constructed.  When a ''Contractor'' designs a ''project'', the ''Contractor'' is deemed to be the ''Design Authority''.
-<li>{{hilite |''Finished roof system surface''|| 2020-February-3 }} {{hilite | means the top surface of any ''roof system'', inclusive of ballast or ''overburden''|| 2021-February-7 }}.
+<li>{{hilite | ''Finished system surface'' means the top surface of any waterproofing or water-shedding system, inclusive of ballast or ''overburden''|| 2027-June-11 }}.
 <li>''Grade-level waterproofing system'' means an insulated or uninsulated ''system'', designed and constructed at grade with a sheet or liquid-applied membrane, to exclude water.
-<li>{{hilite | ''Linear metal flashing''|| 2021-June-30 }} {{hilite | means flashings cut and shaped from flat metal stock, to redirect water at roof perimeters and edges, or to control the flow of water in valleys and drainage spillways.  ''Linear metal flashings'' also protect roof membranes from weathering and damage and provide an aesthetic finish to the ''roof system''|| 2021-June-30 }}.
+<li>{{hilite | ''Linear metal flashing'' means flashings cut and shaped from flat metal stock, to redirect water at roof perimeters and edges, or to control the flow of water in valleys and drainage spillways.  ''Linear metal flashings'' also protect roof membranes from weathering and damage and provide an aesthetic finish to the ''waterproofing system''  or ''water-shedding system''|| 2027-June-11 }}.
 <li>{{hilite | ''Guarantor'' (used interchangeably with '''''RGC''''') means the RCABC Guarantee Corporation, which offers the '''''RoofStar Guarantee'''''. || 2023-June-16 }}
 <li>{{hilite | ''Membrane system'' means the combination of field and flashing membranes which function together to waterproof underlying materials and ''systems''. || 2023-June-16 }}
 <li>{{hilite | ''Observer'' means a firm or person paid by the building Owner (directly, or through the '''''RGC'''''), who is independent (not a member) of the RCABC, and who is accepted by the '''''RGC''''' to provide Quality Assurance reviews during construction and after completion of the ''project'', according to the terms and conditions set out in RCABC policy || 2025-October-25 }}.
 <li>{{hilite | ''Qualified roof condition surveyor'' means a person trained and competent in the use and interpretation of infrared thermographic and electronic moisture scanning equipment, used in the condition assessment of a roof || 2026-October-31 }}.
 <li>{{hilite | ''Vegetated Roof Assembly'' (''VRA''), used interchangeably in the "RGC Standard for Vegetated Roofs" with ''green roof'' or ''green roofing'', means a functional arrangement of interacting components, inclusive of ''vegetation'', that is designed in conjunction with a supporting ''roof assembly'', is intended to both grow and flourish, and is often installed on a roof to control the rate of rainwater discharged through a storm drainage system || 2025-October-25 }}.
-<li>''Waterproofing roof system'' means an insulated or uninsulated ''roof system'', designed and constructed on roofs using a sheet or liquid-applied membrane, to exclude water.  This type of ''system'' typically is installed on roof slopes less than 1:4 (3” in 12”).
+<li>{{hilite | ''Waterproofing system'' means a sealed, functional arrangement of ''primary materials'' constructed on roofs, plaza ''decks'', or on grade-level slabs (with or without insulation and other related materials), to resist the transmission of liquid water through the system, including water under hydrostatic pressure|| 2027-June-11 }}.
 <li>''Water-shedding roof system'' means an insulated or uninsulated ''roof system'', designed and constructed to shed water away from a structure, not to waterproof it.  This type of ''system'' typically is installed on roof slopes greater than 1:4 (3” in 12”) but may be installed on slopes as low as 1:6 (2" in 12").
 </li></ol>

@@ Line 4,228: / Line 4,228: @@
 <li>''Roof drains'' on new construction ''projects'' must be located at least {{hilite | 457.2 mm (18") || 2024-June-15 }} {{strike| 304.8 mm (12”) || 2023-June-15 }} away from any adjacent drain, penetration, upstand, edge, or wall (the separation space is measured between openings, excluding the flange), but this requirement does not apply to ''overflow drains'', ''scupper drains'', and membrane gutters (Ref. [[#11.3.3.7. Scuppers and Overflows | Article 11.3.3.7.]] for minimum requirements applicable to ''scuppers'' and ''overflows'').
 <li>{{hilite | Notwithstanding the requirements in Sentence (1), a cast iron ''roof drain'' with a sump receiver must be placed well away from any interference with drain securement. || 2024-June-15 }}
-<li>When {{hilite | a roof is replaced and || 2024-June-15 }} existing ''roof drain'' {{strike| and penetration locations || 2023-June-15 }} do not comply with the spacing requirements in this Part, the ''Design Authority'' must submit {{strike| a written request for a Variance, following the requirements in [[#1.1.3.6. Variances | Article 1.1.3.6., "Variances"]] || 2023-June-15 }}{{hilite | a drawn detail for a review by the '''''Guarantor'''''; the detail must incorporate the following requirements and principles, together with requirements in Subsection 11.3.3 || 2024-June-15 }}:
+<li>When {{hilite | a roof is replaced and || 2024-June-15 }} existing ''roof drains'' {{strike| and penetration locations || 2023-June-15 }} do not comply with the spacing requirements in this Part, the ''Design Authority'' must submit {{strike| a written request for a Variance, following the requirements in [[#1.1.3.6. Variances | Article 1.1.3.6., "Variances"]] || 2023-June-15 }}{{hilite | a drawn detail for a review by the '''''Guarantor'''''; the detail must incorporate the following requirements and principles, together with requirements in Subsection 11.3.3 || 2024-June-15 }}:
 <ol>
 <li><span class="principles">{{hilite | Specify sheet membrane flashing to seal in the drain to the field membrane (liquid membranes should be the last option) || 2024-June-15 }}</span>.