(Draft) Notes to GLW Standard - Revision history

James Klassen: /* Notes to Part 10 */

2026-06-19T22:24:57Z

‎Notes to Part 10

James Klassen: /* Notes to Part 9 */

2026-06-19T22:17:31Z

‎Notes to Part 9

James Klassen: /* A-9.1.3.3. System Securement */

2026-06-19T22:14:13Z

‎A-9.1.3.3. System Securement

James Klassen: /* Notes to Part 8 */

2026-06-19T22:13:09Z

‎Notes to Part 8

James Klassen: /* Notes to Part 7 */

2026-06-19T22:12:50Z

‎Notes to Part 7

James Klassen: /* A-6.1.3.1. Responsibility for Design */

2026-06-19T22:06:10Z

‎A-6.1.3.1. Responsibility for Design

James Klassen: /* A-6.2.1.2. Prohibited Materials for RoofStar Guarantee */

2026-06-19T22:03:29Z

‎A-6.2.1.2. Prohibited Materials for RoofStar Guarantee

James Klassen: /* Notes to Part 5 */

2026-06-19T22:00:22Z

‎Notes to Part 5

James Klassen: /* Notes to Part 3 */

2026-06-19T21:54:17Z

‎Notes to Part 3

Show changes

James Klassen: /* Notes to Part 2 */

2026-06-19T21:48:34Z

‎Notes to Part 2

@@ Line 196: / Line 196: @@
 ===<big><span class="reference">Notes to Part 10</span></big>===
 <div id=A-10.1.6.1.></div>
 ====A-10.1.6.1. Expansion Joints====
-:Roof expansion joints, or movement joints, are designed to safely absorb thermal expansion and contraction of materials, or to absorb vibration.  This is especially critical on large roof areas where the expansion and contraction rates of materials, such as insulation panels, can adversely affect membranes and induce ''racking''; by dividing the roof into smaller area units, these effects can be ameliorated.
+:''Waterproofing assembly'' expansion joints, or movement joints, are designed to safely absorb thermal expansion and contraction of materials, or to absorb vibration.  This is especially critical on large areas of a ''project'' where the expansion and contraction rates of materials can adversely affect membranes; by dividing the roof into smaller area units, these effects can be ameliorated.
 :Expansion joints also allow for movement caused by settlement and earthquakes.
 <div id=A-10.1.6.2.></div>
+====A-10.1.6.2. Control Joints (System Dividers)====
 :''Control joints'' (sometimes referred to as roof dividers) are site-built but relatively uncommon for roofs with flexible membranes. They are designed to help control thermal expansion and contraction stresses in the roof ''system'' where no structural expansion joint has been provided in the building design, by dividing large roof areas into smaller ones. ''Control joints'' may be present on older roofs with built-up roof systems, and will have to be taken into consideration by the ''Design Authority''; in some cases, ''control joints'' may be eliminated for replacement roofing.  Still, control joints may be employed by the ''Design Authority'' to control expansion and contraction of any materials in the ''roof system'', or for dividing existing roof areas for phased replacement roofing.
-:{{hilite | ''Control joints'' may be employed to divide a large roof area into smaller roof areas, for the purpose of phasing replacement roofing. || 2023-June-16 }}
+:''Control joints'' may be employed to divide a large roof area into smaller roof areas, for the purpose of phasing replacement roofing.
 <div id=A-10.2.1.1.(2)(3)></div>
 ====A-10.2.1.1.(2)(3) Flashing Membrane====
-:{{hilite | Some membranes that satisfy the criteria in Article 10.2.1.1. are listed in Division C but were accepted for use on ''water-shedding roof systems'' (i.e., Architectural Sheet Metal, or Asphalt Shingles).  When the ''Design Authority'' specifies one of these materials for application on a ''tall parapet'', it must be declared suitable for the purpose by the ''manufacturer'' of that membrane. || 2024-January-31 }}
+:Some membranes that satisfy the criteria in Article 10.2.1.1. are listed in Division C but were accepted for use on ''water-shedding roof systems'' (i.e., Architectural Sheet Metal, or Asphalt Shingles).  When the ''Design Authority'' specifies one of these materials for application on a ''tall parapet'', it must be declared suitable for the purpose by the ''manufacturer'' of that membrane.
 <div id=A-10.3.7.2.></div>
 ===={{hilite | A-10.3.7.2. Intersections with Water-Shedding Roofs || 2025-October-25 }}====
-:The maximum water level is the point where water naturally spills off a roof (for example, through an overflow drain).  When a roof is not constructed with overflows, the spill-over point will be the top of the lowest roof edge detail (typically a parapet (See Article 11.1.4.2.).  ''Roof drains'' may be unmaintained and severe storms or freeze-thaw cycling during winter months may interfere with a roof's ability to drain.  Therefore, the waterproofing of the roof (and also the load design) should allow for a worst case scenario in which the roof fills to its maximum capacity.  Contemplating such a scenario should give the designer pause when considering low-clearance openings in ''walls'' (i.e., doors, windows, and ventilation grilles), which may serve as ''de facto'' 'overflows' when other drains are inoperable.
+:The maximum water level is the point where water naturally spills off a system (for example, through an overflow drain).  When a ''waterproofing system'' is designed with ''parapets'' and mechanical (plumbed) ''drains'' but is not constructed with ''overflows'', the spill-over point will be the top of the lowest edge detail. typically a parapet (See Article 11.1.4.2.).  ''Drains'' may be unmaintained and severe storms or freeze-thaw cycling during winter months may interfere with a ''waterproofing system's'' ability to drain.  Therefore, the waterproofing (and also the load design) should allow for a worst case scenario in which the ''waterproofing system'' to its maximum capacity.  Contemplating such a scenario should give the designer pause when considering low-clearance openings in ''walls'' (i.e., doors, windows, and ventilation grilles), which may serve as ''de facto'' 'overflows' when other drains are inoperable.
-:The effects of weather cannot be overstated.  While an absence of maintenance is often faulted for blocked ''roof drains'' and ''overflows'', snow and ice can radically alter the drainage of a roof; in some instances, where freezing rain coats snow on the roof, the encrusted top surface of the snow forms a new plane of drainage.  Seasonal phenomena like this affect every detail on a roof - penetrations, curbs, and perimeter membrane flashing.  While RGC Standards publish minimum requirements for membrane flashing, those minimums do not contemplate every possible condition that might affect a building.  It is therefore incumbent upon the ''Design Authority'' to specify membrane flashing heights for the expected service conditions of the roof, for its location (Ref. British Columbia Building Code, Div. A, [https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/construction-industry/building-codes-and-standards/revisions-and-mo/bcbc_2024.pdf#page=82 Functional Statement 80]).
+:The effects of weather cannot be overstated.  While an absence of maintenance is often faulted for blocked ''drains'' and ''overflows'', snow and ice can radically alter the drainage of a ''waterproofing assembly''; in some instances, where freezing rain coats snow on the assembly, the encrusted top surface of the snow forms a new plane of drainage.  Seasonal phenomena like this affect every detail on an assembly - penetrations, curbs, and perimeter membrane flashing.  While RGC Standards publish minimum requirements for membrane flashing, those minimums do not contemplate every possible condition that might affect a building.  It is therefore incumbent upon the ''Design Authority'' to specify membrane flashing heights for the expected service conditions of the roof, for its location (Ref. British Columbia Building Code, Div. A, [https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/construction-industry/building-codes-and-standards/revisions-and-mo/bcbc_2024.pdf#page=82 Functional Statement 80]).
 :{| class="wikitable"; table style="background-color:white"; border="#A9A9A9;"

@@ Line 190: / Line 190: @@
 ===<big><span class="reference">Notes to Part 9</span></big>===
-<div id=A-9.1.3.3.></div>
+<div id=A-9.3.2.2.(2)></div>
-====A-9.1.3.4. Membrane Protection====
+====A-9.3.2.2.(2) Preparation of Substrate====
-:Sunlight reflected from windows, doors, cladding and other reflective materials can elevate roof surface and sub-surface temperatures, which may shorten the life of a membrane and the ''roof system'' materials beneath it, and may cause irreparable damage.  Roofs oriented to face south and southwest are particularly vulnerable to these effects, and sunlight reflected from metal can be more damaging than light reflected by glass.
+:Proper water curing techniques are strongly recommended and include continual or frequent applications of water by ponding or immersion, spraying or fogging. Concrete ''decks'' cured with compounds or sealants may not have acceptable surfaces to receive adhered waterproofing membranes. When concrete curing compounds are used on waterproofing ''decks'' removal of the compounds by mechanical means, may be necessary prior to installation of membranes, and such removal is the responsibly of others not the waterproofing contractor.
 ===<big><span class="reference">Notes to Part 10</span></big>===

@@ Line 191: / Line 191: @@
 ===<big><span class="reference">Notes to Part 9</span></big>===
 <div id=A-9.1.3.3.></div>
 ====A-9.1.3.4. Membrane Protection====

← Older revision		Revision as of 22:13, 19 June 2026
Line 188:		Line 188:

	===<big><span class="reference">Notes to Part 8</span></big>===		===<big><span class="reference">Notes to Part 8</span></big>===
−	~~<div id=A-8.1></div>~~
−
−	~~====A-8.1 Design====~~
−	~~:Insulation overlay boards are installed in most ''conventionally insulated systems'' to~~
−	~~:*protect ''heat-sensitive insulation'' materials from damage by heat and flame.~~
−	~~:*protect insulation materials from accidental impact.~~
−	~~:*provide dimensional stability to the ''roof system''.~~
−	~~:*distribute dead loads from heavy overburdens or equipment installed on top of the ''finished waterproofing system''.~~
−	~~:*ensure the membrane performs as it should.~~
−	~~:*provide a suitable substrate for membrane application.~~
−
−	~~:Insulation overlay boards may be mechanically attached or adhered, depending upon the insulation type and the design requirements of the entire ''roof assembly''.~~

	===<big><span class="reference">Notes to Part 9</span></big>===		===<big><span class="reference">Notes to Part 9</span></big>===

@@ Line 174: / Line 174: @@
 ====A-7.1.3.1 Responsibility for Design====
-:{{hilite | Insulation materials rely on various standards for the determination of thermal resistance, which means that not all data can be easily compared. Furthermore, not all insulation products perform with consistent thermal resistance as temperature changes, and some insulation performance declines with age. Therefore, refer to the "Long-term Thermal Resistance" (LTTR) for each insulation product, in relation to the product's placement within the roof assembly and the anticipated outside and interior climates of the building. || 2023-June-16 }}
+:Insulation materials rely on various standards for the determination of thermal resistance, which means that not all data can be easily compared. Furthermore, not all insulation products perform with consistent thermal resistance as temperature changes, and some insulation performance declines with age. Therefore, refer to the "Long-term Thermal Resistance" (LTTR) for each insulation product, in relation to the product's placement within the ''waterproofing assembly'' and the anticipated outside and interior climates of the building.
-:{{hilite | Also see the "British Columbia Building Code", Division B, Part 10 (Ref. Div. B, Section 9.25., "Heat Transfer, Air Leakage and Condensation Control" for structures governed by Part 9), together with relevant requirements in Division A and Division C of the Building Code. || 2023-June-16 }}
+:Also see the "British Columbia Building Code", Division B, Part 10 (Ref. Div. B, Section 9.25., "Heat Transfer, Air Leakage and Condensation Control" for structures governed by Part 9), together with relevant requirements in Division A and Division C of the Building Code.
 <div id=A-7.1.3.4.></div>
-====A-7.1.3.4. {{strike| Effective || 2026-January-31 }} {{hilite | Thermal Resistance and Layering|| 2027-February-1 }}====
+====A-7.1.3.4. Thermal Resistance and Layering====
-:{{hilite | In warm seasons, the roof surface may reach temperatures higher than 85°C (185°F), affecting the performance and stability of some insulation. Consequently, the requirement which limits panel size in single-layer applications ensures that inevitable gaps between adjacent panels are kept to a minimum.  Combining insulation types in a ''roof system'' may help mitigate these temperature swings and the consequence of thermal contraction. The ''Design Authority'' therefore must consider these variables when specifying materials and their installation. || 2023-June-16 }}
+:In warm seasons, high temperatures may adversely affect the performance and stability of some insulation. Consequently, the requirement which limits panel size in single-layer applications ensures that inevitable gaps between adjacent panels are kept to a minimum.  Combining insulation types in a ''roof system'' may help mitigate these temperature swings and the consequence of thermal contraction. The ''Design Authority'' therefore must consider these variables when specifying materials and their installation. || 2023-June-16 }}
-:{{hilite | While multi-layering insulation is required when the cumulative thermal resistance of all insulation exceeds RSI-2.64 (R-15), it is important to note that most insulation types naturally experience dimensional change in all 3 planes as outside temperatures and sun exposure change throughout the day (mineral fibre insulation being the general exception).  The degree of expansion or contraction directly corresponds with the thickness of the panel; the greater the thickness and panel size, the larger the movement.  Considerable movement may create unexpected issues with the roof; shrinkage and resulting gaps between insulation panels may introduce thermal loss, and movement that telegraphs to the supporting roof surface may produce membrane wrinkling.    To reduce the consequences of thermal movement, the ''Design Authority'' should consider specifying maximum layer thickness; any leaks attributed to ''roof system'' movement are excluded from coverage under a '''''RoofStar Guarantee'''''|| 2025-October-25}}.
+:While multi-layering insulation is required when the cumulative thermal resistance of all insulation exceeds RSI-2.64 (R-15), it is important to note that most insulation types naturally experience dimensional change in all 3 planes as outside temperatures and sun exposure change throughout the day (mineral fibre insulation being the general exception).  The degree of expansion or contraction directly corresponds with the thickness of the panel; the greater the thickness and panel size, the larger the movement.  Considerable movement may create unexpected issues with the roof; shrinkage and resulting gaps between insulation panels may introduce thermal loss, and movement that telegraphs to the supporting roof surface may produce membrane wrinkling.    To reduce the consequences of thermal movement, the ''Design Authority'' should consider specifying maximum layer thickness; any leaks attributed to ''roof system'' movement are excluded from coverage under a '''''RoofStar Guarantee'''''.
-:{{hilite | The "Long-Term Thermal Resistance" (LTTR) measurement of closed-cell insulation materials remains the standard by which insulation performance is measured.  Published R-values should reflect the LTTR of the material.  In Canada, two principal standards apply to the accurate measurement of thermal resistance: CAN/ULC-S770 ("Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams") and CAN/ULC-S704.1 ("Standard for Thermal Insulation, Polyurethane and Polyisocyanurate, Boards, Faced"). || 2023-June-16 }}
+:The "Long-Term Thermal Resistance" (LTTR) measurement of closed-cell insulation materials remains the standard by which insulation performance is measured.  Published R-values should reflect the LTTR of the material.  In Canada, the standard that applies to insulation used in ''waterproofing systems'', for the accurate measurement of thermal resistance, is CAN/ULC-S770 ("Standard Test Method for Determination of Long-Term Thermal Resistance of Closed-Cell Thermal Insulating Foams").
 ===<big><span class="reference">Notes to Part 8</span></big>===

@@ Line 163: / Line 163: @@
 :Air and vapour control layer performance is not part of the '''''RoofStar Guarantee''''', and air and vapour control materials are not listed in [[Division C | Division C]].
-:In some ''roof assembly'' designs, the required underlayment may serve as an air control layer, vapour control layer, or both; this is dependent upon the properties of the material to be used and will be subject to the designer’s modelling of the ''assembly''.  Consult the Technical Data Sheets for suitable materials.
+:In some ''waterproofing assembly'' designs, materials that control air movement may also serve as a vapour control layer; this is dependent upon the properties of the material to be used and will be subject to the designer’s modelling of the ''assembly''.  Consult the Technical Data Sheets for suitable materials.
 <div id=A-6.2.1.2.></div>

@@ Line 168: / Line 168: @@
 ====A-6.2.1.2. Prohibited Materials for RoofStar Guarantee====
-:Constructability, and resistance to damage, heat, and to solvent-based products, are key properties of air and vapour control materials.  While the '''''RoofStar Guarantee''''' does not extend coverage to air and vapour control materials, or to their performance (Ref. Note A-6, "Air and Vapour Controls"), leaks through or past damaged or poorly sealed materials can adversely affect the performance of the guaranteed ''roof system''. For this reason, both polyethylene plastic sheet products and bitumen-impregnated kraft paper are not permitted in a roof intended to qualify for a '''''RoofStar Guarantee'''''; both materials are easily damaged (punctured) during construction, and proper sealing of each material to itself and to adjoining materials is difficult.
+:Constructability, and resistance to damage, heat, and to solvent-based products, are key properties of air and vapour control materials.  While the '''''RoofStar Guarantee''''' does not extend coverage to air and vapour control materials, or to their performance (Ref. Note A-6, "Air and Vapour Controls"), leaks through or past damaged or poorly sealed materials can adversely affect the performance of the ''waterproofing system'', particularly where it joins ''wall'' assemblies. For this reason, both polyethylene plastic sheet products and bitumen-impregnated kraft paper are not permitted in any part of a  ''waterproofing system'' that qualifies for a '''''RoofStar Guarantee'''''; both materials are easily damaged (punctured) during construction, and proper sealing of each material to itself and to adjoining materials is difficult.
 ===<big><span class="reference">Notes to Part 7</span></big>===

@@ Line 137: / Line 137: @@
 ====A-5 Deck and Wall Overlays====
 :This Part addresses materials that are acceptable as overlays used to render a deck or wall surface suitable for roofing.  This Part supports the substrate preparation requirements in Parts 9 and 10.
 ===<big><span class="reference">Notes to Part 6</span></big>===

@@ Line 99: / Line 99: @@
 ====A-2 Scope and Application of Part 2====
-:Part 2 addresses ''deck'' and ''wall'' materials, deck slope, ''deck'' and ''wall'' conditions, and the methods by which intersecting systems such as electrical wiring can be executed safely and in alignment with the interests of the '''''Guarantor'''''.  It does not address construction or installation of ''decks'' and ''walls'', which is the work of other trades.  For the preparation of a ''roof deck'' to render a deck or wall suitable for roofing, refer to Part 9 and Part 10, in the articles pertaining the substrate preparation.
+:Part 2 addresses ''deck'' and ''wall'' materials, deck slope, and ''deck'' and ''wall'' conditions.  It does not address construction or installation of ''decks'' and ''walls'', which is the work of other trades.  For the preparation of a ''roof deck'' to render a deck or wall suitable for roofing, refer to Part 9 and Part 10, in the articles pertaining the substrate preparation.
 <div id=A-2.1.5.1.></div>
@@ Line 121: / Line 109: @@
 ====A-2.1.5.2. Concrete Roof Decks====
-:Concrete ''decks'' to which a ''roof system'' may be applied include
+:Concrete ''decks'' to which a ''waterproofing system'' may be applied include
 :*Cast-in-place.
 :*Pre-cast panels.
 :*Pre-stressed panels.
 :*Lightweight.
 <div id=A-2.1.7.></div>
 ====A-2.1.7. Walls====
-:''Walls'' and roofs intersect either directly (where the ''wall'' structurally connects to the roof structure, so that both move together), or indirectly (where the roof structure and the ''wall'' structure are independent of each other, so that the movement of one does not affect the other).  These locations require an expansion joint.
+:''Walls'' and the field of a ''waterproofing assembly'' intersect either directly (where the ''wall'' structurally connects to the ''deck'' structure, so that both move together), or indirectly (where the ''deck'' structure and the ''wall'' structure are independent of each other, so that the movement of one does not affect the other).  These locations require an expansion joint.
 ===<big><span class="reference">Notes to Part 3</span></big>===