Grade-level Waterproofing Standard

This section contains the Standards, Guiding Principles, Recommendations and reference materials necessary for the design and installation of a roof qualifying for a RoofStar Guarantee.

How to use the Guarantee Standards section:How to use the Guarantee Standards section:

All relevant Standards for the selection and application of materials necessary to qualify for a RoofStar Guarantee are found in this section. Readers are advised to review relevant materials that can be accessed through the links available in the body of text or embedded in section titles; these are shown in blue font. Subsection titles shown in blue indicate links to more relevant material that the reader is advised to consult.

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1 ABOUT WATERPROOFING

1.1 Waterproofing versus Dampproofing

The definition of waterproofing is the treatment of surfaces or structures in order to prevent the passage of water under hydrostatic pressure. In contrast dampproofing is defined as the treatment of surfaces or structures to resist the passage of water in the absence of hydrostatic pressure. The hydrostatic pressure exerted by water lying against a barrier increases steadily in pressure as the depth of water increases. Water exerts a pressure of 1000kg per meter squared per meter of depth or 62.2 pounds per square foot per foot of depth. Standing water is often present on plaza decks which are typically horizontal low-sloped suspended structural decks over occupied spaces, subsequently this makes waterproofing and protected roofing systems, not dampproofing, the only reliable options to prevent the passage of water into structures.

1.2 Comparisons: Waterproofing, Conventional & Protected Membrane Roof Systems

The differences between waterproofing and low slope protected roofing membrane systems can be very subtle with many manufacturers' membranes often being interchangeable for both roofing as well as waterproofing applications on plaza decks. The two main features differentiating protected membrane roofing systems from waterproofing systems are the membrane flashing application techniques used at construction details and the type of wearing and or protection course used over the membrane assemblies. In contrast conventional roof systems are typically installed over insulations with the primary roof membrane exposed to weather or protected by light aggregates or coatings. (For additional technical information on Protected Membrane Roofing Systems refer to Section 3.13 of this manual, RPM).

2 GENERAL REQUIREMENTS

The information provided in this section of the RCABC Roofing Practices Manual (RPM) contains standards to follow for RoofStar guarantee coverage. It also includes technical information and recommendations to assist designers and applicators with waterproofing membrane applications on plazas, promenades and terraces. The formulation of the content of this section of the RPM is based upon the advice of, and information from, architects, manufacturers as well as the experiences of RCABC member professional roofing and waterproofing contractors.

Plaza, promenade and terrace deck waterproofing membrane systems that are accepted for use in the RoofStar Guarantee Program include SBS Modified Bituminous, Polyvinyl Chloride (PVC) and Butyl (Isobutylene & Isoprene) pre-manufactured membranes as well as Hot Fluid-Applied, Reinforced Rubberized Asphalt Systems. RGC accepted waterproofing systems are listed under Accepted Materials section of this Manual. In order to qualify for full coverage under the RoofStar Guarantee Program the waterproofing system as well as installation details must comply with RGC Guarantee Standards E and Membrane Manufacturer's specifications for plaza, promenade or terrace decks applications.

Guarantee Standards E are applicable to Plazas / Promenades and Terraces only. Vehicle parking structures, below grade walls, foundations, and repairs or renovations to existing waterproofing systems do not qualify for RGC guarantee coverage. In addition, all waterproofing system components, including but not limited to membrane protection materials, drainage layers, overburdens including wearing course materials, must comply with and be installed to RGC Guarantee Standards E, in order to qualify for RGC guarantee coverage.

2.1 Application

2.1.2 Material Acceptance

Waterproofing materials and systems covered by the RoofStar Guarantee Program must be accepted by RGC. See the list of Accepted Materials in this Manual.

2.2 Decks

2.2.1 Deck Slopes

A minimum slope of 1:50 (l/4" in 12") is strongly recommended for waterproofing systems, but positive slope to drain is an absolute requirement. To take advantage of future loading deflections drains should be located at mid-spans between deck supporting columns, whenever practical, and especially when deck slopes are less than 1:50 (1/4” in 12”). Positive slope to drain is attained when no standing water remains on the deck within a reasonable amount of time after rainfall stops during days with conditions that permit evaporation. Refer to Essential Elements: Roof Decks for additional information on decks and the definition of slope to drain.

2.2.3 Wood

.1 Wood decks are not acceptable substrates for waterproofing systems that are covered under the RGC Guarantee Program. (Refer to Section 3 for information on wood decks for Roofs.)

(From 9.0.4.3 WOOD DECKS)

Wood decks are not an acceptable substrate for waterproofing systems covered under the RoofStar Guarantee Program. However, if wood is utilized as the substrate material for waterproofing applications RCABC strongly recommends the use of marine grade plywood of a minimum thickness of 15.9mm (5/8"). Plywood surface for waterproofing must be clean dry and smooth and free of holes and joints or gaps between panels.

Solid blocking under non-supported edges and or the use of tongue-and-groove sheathing must prevent differential edge movements of deflection in excess of 1/360 of the span in plywood decks used for waterproofing. Fasteners used to attach plywood substrates for waterproofing must be corrosion-resistant countersunk screws so as to prevent fastener back out and puncturing of membranes. Nails are not recommended fasteners for the attachment of plywood substrates for waterproofing applications adhered directly to wood decks.

2.2.4 Concrete

.1 Concrete decks, walls, curbs and equipment pad surfaces must be clean, dry, and smooth prior to commencement of waterproofing installations. Concrete decks, walls, curbs and equipment pads are not to receive adhered waterproofing for a minimum of 28 days after pouring unless expressly instructed in writing by the Project Structural Engineer. Decks formed with shot-crete and lightweight insulating concrete are not acceptable substrates for waterproofing under the RGC Guarantee Program.

.2 The moisture content levels of concrete surfaces, decks, walls, curbs and equipment pad surfaces, must strictly comply with the membrane manufacturer’s published moisture level application limitations.

.3 Pre-cast panels, post-stressed beams, or “T” and cavity decks shall have a minimum 50mm (2”) concrete topping applied over the deck prior to the application of the waterproofing membranes. Where a difference exists in the levels of adjacent surfaces, the general contractor or others shall install approved non-shrink grout or ground to match level of adjacent surfaces. Grouting or grinding shall be feathered on the lower surface a minimum distance of twelve times the amount of the vertical differential.

.4 Cold joints between concrete pours, at transitions between horizontal decks and vertical walls below grade, shall be sealed and covered with waterproofing membrane flashing. Membrane flashing shall cover all deck wall transitions by a minimum of 200mm (8”) and both deck and wall waterproofing or damp proofing materials must be compatible with one another. Or alternatively, whenever materials at deck and below grade wall transitions are not compatible with one another sealants and mechanically attached termination bars are acceptable, to create a watertight lap a minimum 200mm (8”) in width.

Concrete Surface Preparation

.1 Concrete surfaces shall be free from dirt, loose particles, sharp projections, paint, silicone, oil, grease, and curing compounds or agents as well as other contaminants. Pitted or honey-combed surfaces must be repaired before the membrane application and is the responsibility of others, not the waterproofing contractor, unless specified otherwise.

.2 All concrete surfaces to receive adhered waterproofing shall be structurally sound, water cured, have a light hair broom finish or be prepared by mechanical means and shall be primed, when applicable, with a membrane manufacturer’s approved primer. 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.

(From 9.0.4.1 CONCRETE DECKS)

Cast in place, monolithic structural concrete slabs and precast concrete panels with concrete topping (average 50mm thick) as well as concrete toppings over steel decks make the best substrate and are the most common deck types used for plaza, promenade and terrace waterproofing substrates. Light weight insulating concrete and shotcrete formed concrete decks are not good substrates for waterproofing and therefore are not acceptable decks for waterproofing systems covered under the RoofStar Guarantee Program.

RGC strongly recommends a minimum of 2% (1/4" to ft.) slope to drain for all substrates that receive waterproofing but positive slope to drain is an absolute requirement. It is recommended that drains be located at mid-spans between deck supporting columns whenever deck slopes are less than 1:50 (1/4" in 12") in order to take advantage of expected loading deflections. Positive slope to drain is attained when no standing water remains on the deck 48 hours after a rainfall stops during days with temperatures that permit evaporation. Standard weight concrete (150 pcf) can experience deflection resulting from long-term creep due to loading and to assure permanent retention of a minimum of 1% (1/8" to ft.) an initial slope of at least 2% is strongly recommended for concrete decks. Creep in structural concrete, both reinforced and pre-stressed, due to increasing constant prolonged loading can result in deck deflections equal to three times instantaneous elastic deflection. Therefore, plaza decks with heavy overburdens (loading) require special attention from the structural engineer during the design process to ensure that load carrying capacity of the deck is adequate. The structural design of plazas must also contend with possible intermittent live loads that may exceed 50% of the total design load. The service weight of emergency vehicles such as fire trucks can concentrate excessive live loads on plaza decks that are often designed to provide access for emergency vehicles. Concrete waterproofing decks include decks that are cast-in-place or pre-cast, and structural or non-structural in nature. The finished surface of the deck should be smooth, level, and free of moisture or frost. With cast-in-place decks, special care must be taken to ensure that the deck is cured for 28 days and that the surface is dry. For compliance with National Building Code of Canada provisions for the design and construction of buildings their structural members made of plain, reinforced and pre-stressed concrete shall conform to CSA A23.3 "Design of Concrete Structures". (Refer to RGC Guarantee Standards E)

A. Concrete Deck Surface Preparations

RGC Guarantee Standards require that concrete decks cure a minimum of 28 days to allow sufficient time for moisture to dissipate from the top surface. The responsible trade must rigorously prepare concrete substrates for adhered waterproofing/roofing applications. The concrete must be smooth dry and clean, be fully cured, free of sharp fins and other irregularities including adhesion inhibiting curing compounds and release agents. Holes or voids in the concrete substrates must be re-pointed with a non-shrinking concrete patching compound. Curbs, blocking, and nailing strips should be installed where required prior to the waterproofing contractor's acceptance of the deck. Manufacturer's application specifications for most waterproofing materials require a steel or wood trowelling finish plus a light hair broom finish. (Refer to RGC Guarantee Standards E)

B. Substrate Moisture Emissions

Concrete decks can retain water for extended periods and when exposed to rain the drying time will be extended beyond 28 days. Adhered waterproofing systems require concrete deck moisture levels that are low enough to ensure an adequate bond between the deck and the waterproofing materials. Many waterproofing materials application specifications require that moisture levels emitted from concrete decks not exceed three (3) pounds per thousand square feet.

Testing moisture levels that are emitted from concrete decks prior to material applications is an RGC Guarantee Standard and an essential step in minimizing the impact that the presence of water may have on successful waterproofing application. Moisture meters are used to determine the moisture content of concrete decks and must be performed daily by the applicator prior to waterproofing membrane installations. Capacitance testing meters measure the relative moisture content of the surface of concrete decks in order to determine the suitability of the surface (to 25mm -1" in depth) for the application of adhered materials. (Refer to RGC Guarantee Standards E)

2.2.5 Steel

.1 Poured concrete, gypsum or cement fibre board deck overlays are required over steel decks as acceptable substrates for all adhered waterproofing membrane systems.

.2 Steel Decks with Concrete Overlays Steel decks that receive poured concrete overlays shall have vented pans to prevent entrapment of moisture. For preparation of concrete surfaces for membrane applications refer to E2.3 Concrete Surface Preparation.

.3 Gypsum Boards on Steel Decks Two layers of gypsum board shall be installed over steel decks as an acceptable substrate for waterproofing membranes, each layer shall be a minimum thickness of 12.7 mm (1/2"), be manufactured with fibreglass facers and silicone treated gypsum cores. Gypsum board edges shall to be fully or intermittently supported by the deck and have joints staggered (offset) 300 mm (12") from adjacent boards, rows as well as layers. When required by membrane manufacturer’s application specifications tape all board joints that will receive membrane with waterproofing manufacturer’s approved joint tape. For board surface preparations (e.g. primer) follow membrane manufacturer’s application specifications.

.4 Cement Fibre Boards on Steel Decks Two layers of fibre-mat reinforced cement board shall be installed over steel decks as an acceptable substrate for waterproofing membrane applications and each layer must be a minimum thickness of 9.5 mm (3/8") as well as conform to ASTM C1325-04 Non-Asbestos Fibre-Mat Reinforced Cement Substrate Sheets.. Cement fibre-mat board edges shall to be fully or intermittently supported by the deck and have joints staggered (offset) 300 mm (12") from adjacent boards, rows as well as layers. When required by membrane manufacturer’s application specifications tape all board joints that will receive membrane with waterproofing manufacturer’s approved joint tape. For board surface preparations (e.g. primer) follow membrane manufacturer’s application specifications.

.5 Gypsum Board & Cement Board Attachment on Steel Decks When gypsum or cement boards are mechanically fastened on steel decks, as substrate overlay boards for waterproofing membranes, the first layer of gypsum or cement board shall be either fully mechanically fastened to the deck or be adhered with membrane manufacturer’s approved polyurethane adhesive. The second layer must be adhered with membrane manufacturer’s approved polyurethane adhesive. Mechanical fixation through both deck overlay board layers is not permitted.

.6 Maximum steel deck flute width and minimum fastener requirements for gypsum and cement board used for deck overlay applications are as follows:

Thickness	Deck Flute Width	Board Size	Screws & Metal Stress Plates	Bugle Head Drywall Screws
9.5mm (3/8”)	up to 125mm (5")	1200 mm x 2400 mm (4' x 8’)	12	32
12.7mm (½")	up to 125mm (5")	1200 mm x 2400 mm (4' x 8’)	12	32
15.9mm (5/8")	up to 200mm (8")	1200 mm x 2400 mm (4’ x 8’)	12	32

(From 9.0.4.2 STEEL DECKS) Steel roof decks are most often constructed of light gauge (usually 22, 20, or 18 gauge) cold-rolled steel sections (panels) that are galvanized. In cross-section the panels are ribbed, with the ribs usually spaced at 150 mm (6") on centre. The ribs provide the strength and rigidity of the panels. Steel decks are generally supported by open-web steel joist framing and are welded or mechanically fastened to the framework. Steel decks panels must be properly aligned, squarely intersect walls, and provide a smooth level surface for waterproofing.

For compliance with National Building Code of Canada provisions for the design and construction of buildings their structural members made of cold-formed steel shall conform to Can / CSA -S136-01 (including supplement CAN/CSA -S136S1-04). (Refer to RGC Guarantee Standards E)

2.2.6 A. Steel Deck Substrate Preparations

Two layers of accepted gypsum or cement overlay board is required on steel decks as substrate for adhered waterproofing membranes when cast in place concrete topping is not present. The first layer of gypsum or cement board shall be either be fully mechanically fastened to the deck or adhered to the deck with manufacturer's approved compatible polyurethane adhesive. The second board layer must be adhered with a compatible manufacturer's approved polyurethane adhesive.

All edges of the gypsum & cement boards must be fully or intermittently supported by the deck. Staggered (offset) end and side joints 300 mm (12") from adjacent board rows. All board joints that will receive liquid applied membrane systems must be taped with waterproofing manufacturer's approved joint tape.

Gypsum overlay boards used on steel decks must be RGC accepted with a minimum thickness of 12.7 mm (1/2") and be manufactured with water resistant treated gypsum cores, conforming to ULC S-102 & ULC S-107. (Refer to RGC Guarantee Standards E)

Cement overlay boards used on steel decks must be fibre-mat reinforced cement board with a minimum thickness of 9.5 mm (3/8") that conforms to ASTM C1325-04 (Non-Asbestos Fibre-Mat Reinforced Cement Substrate Sheets).

2.2.7 Expansion Joints

.1 Manufacturer’s proprietary roof expansion joint systems are acceptable for use when the systems are located a minimum of 100mm (4") above the finished roof surface and are completely sheathed (covered) with membrane flashing and sloped metal flashing. (Refer to Construction Drawing Section 10)

.2 Flat profile (deck level) manufacturers proprietary elastomeric expansion joint membrane flashings systems may be used with waterproofing systems provided they are compatible with the waterproofing membrane and acceptable for use by the membrane manufacturer. Elastomeric expansion joints must provide a minimum expansion and contraction rate that meets or exceeds 500% elongation at - 40ºC (- 40ºF) across its length as well as be designed to compensate for the maximum predicted movement.

.3 All flat profile elastomeric expansion joint details and connections shall be factory fabricated by means of vulcanization, must provide a minimum expansion and contraction rate that meets or exceeds 500% elongation at - 40ºC (- 40ºF) at all vulcanized joints. Field splicing of two pieces of flat profile expansion joints, by other than the expansion joint manufacturer, typically by use of adhesives, caulking, taping or hot air welding, is not permitted in the RGC Guarantee Program. (Refer to Construction Drawing Section 9)

(From 9.0.8 EXPANSION JOINTS) Expansion joints are used on waterproofing decks to intentionally provide periodic breaks or gaps to accommodate movement for the expansion and contraction of the buildings as well as thier components. Typically movement is limited to a maximum of 25mm (1"). Expansion joints can be found at changes in deck direction, re-entrant building corners, and changes in deck type as well as on large decks exceeding 61meters (200') additions and buildings with extreme movement (freezers) or when isolation from vibrations is required.

Flat profile expansion joints must be elastomeric expansion waterproofing joints with all details and connections factory fabricated by means of vulcanization. Field splicing of two pieces of flat profile expansion joints by other than the expansion joint manufacturer, typically by use of adhesives, caulking, taping or hot air welding, is not permitted on projects covered under the RoofStar Guarantee Program. Flat profile expansion joints must be designed to accommodate expected building movements and be capable of a minimum of 500% elongation at - 40°C (- 40°F) across its length and at all vulcanized points. (Refer to RGC Guarantee Standards E)

2.5 Tying Into Existing Waterproofing

Where a new waterproofing system is tied-in to an existing system, the waterproofing materials must be compatible with one another, provide a positive water cut-off to the deck and shall have an RGC accepted membrane moisture monitoring sensor grid system installed between the new and existing waterproofing systems. RGC accepted membrane moisture monitoring systems are listed in Section 2.2 (ref Section 9) of the RGC Roofing Practices Manual.

4 SUBSTRATES: Walls and Wall Preparation

.1 Wall Sheathing Gypsum board is not considered an adequate substrate to receive waterproofing on vertical surfaces.

On steel framed walls fibre-mat reinforced cement board with a minimum thickness of 9.5 mm (3/8") that conforms to ASTM C1325-04 (Non-Asbestos Fibre-Mat Reinforced Cement Substrate Sheets) is an acceptable substrate to receive waterproofing. Fibre-mat reinforced cement board is to be supplied by others unless specified otherwise, must be installed by the waterproofing contractor, and covered with membrane the same work day.

.2 Concrete Wall Preparation All concrete or masonry parapets and walls must provide a smooth, clean, dry surface for membrane adhesion. Alternatively walls that do not provide a smooth, clean, dry surface for membrane adhesion may be sheathed with a minimum 15.9 mm (5/8") treated plywood or 9.5 mm (3/8") reinforced cement board that conforms to ASTM C1325-04. Boards must be mechanically attached or adhered to the wall with polyurethane adhesive. When waterproofing is applied directly to masonry parapets or walls follow RGC guarantee standards and manufacturer’s printed instructions.

.3 Walls at Decks Not Supported by the Wall A parapet wall is required at adjoining walls were the deck is not supported by the wall (expansion joint) and shall be sheathed with minimum 15.9 mm (5/8") plywood or 9.5 mm (3/8") reinforced cement board that conforms to ASTM C1325-04. Wall sheathing shall be fastened to preservative treated blocking or to steel stud framing that is attached solidly to the deck and not the wall. Compressible insulation is to be installed between the sheathing and the wall and an accepted expansion joint membrane as well as metal counter flashing shall be installed.

.4 Planter Walls Non-structural planter walls that are located above protection and drainage board layers, without penetrating waterproofing membranes, are strongly recommended whenever practical. When planter walls have structural reinforcements that penetrate membranes only the use of pre-curbs or start-up curbs that are a minimum height of 100mm (4”) above the deck are acceptable for coverage under the RGC Guarantee Program. Refer to construction drawing Planter Pre-Curb Wall in Section 9 for planter curb construction, membrane and flashing installation, as well as sealant requirements for penetrating reinforcements.

5 MEMBRANES

5.1 General

.1 RGC specifically accepted waterproofing membrane systems listed in Section 2.2, of the RCABC Roofing Practices Manual (RPM), as Accepted Materials include the following:

• Two Ply SBS Modified Bituminous Membranes
• Butyl Elastomeric Single Ply Membranes
• Poly Vinyl Chloride (PVC) Plastomeric Single Ply Membranes
• Hot Fluid - Applied, Rubberized Asphalt Systems.

.2 Only waterproofing membrane systems that are fully adhered and have an accepted protection layer installed above the membrane (protected) qualifies for coverage under the RGC Guarantee Program. For information on Protected and Modified Protected Roofing refer to Section 2.1 C and Section 5 of this manual.

.3 All waterproofing system accessory components must be supplied or be accepted for use by the membrane manufacturer. Refer to Section 9 for individual manufacturer accessory components and material listings.

.4 All materials must be protected from weather by properly stacking above ground or deck surfaces and keep in factory packaging or other adequate covering until applied.

5.2 Material Selection

5.2.1 SBS Modified Bitumen Membranes

.1 All SBS Modified Bituminous membrane waterproofing systems shall consist of two plies of membrane. The top ply or cap sheet shall have a minimum thickness of 2.9 mm and a minimum reinforcement weight of 180g/meter squared polyester or equal strength combination reinforcement. In addition, both base plies and cap sheets in combination shall have a minimum thickness of 6.0mm or greater.

.2 Both the base sheet and cap sheet must be installed in a parallel direction (not at 90° to each other). Manufacturer's published instructions for membrane overlaps, sheet installation configurations, corner gussets (reinforcement) and membrane flashing applications shall be strictly followed. Membrane reinforcement gussets shall be installed at all inside and outside corner transitions prior to installation of membrane flashing (stripping).

.3 Only fully adhered SBS base and cap sheets that are either torch applied or are adhered in hot fluid applied rubberized asphalt qualify for coverage under the RGC waterproofing guarantee program. NOTE: Direct torch applications to wood surfaces are not permitted.

.4 Membrane end lap corners must be cut on a bias (clipped or trimmed on an angle) prior to forming laps on all torch applied modified bituminous membranes and granules are to be embedded on cap sheets prior to forming laps or seams.

5.2.2 Thermoset Membranes

.1 Butyl single ply thermoset waterproofing membranes used for waterproofing systems shall be fully adhered to RGC accepted substrates and shall be a minimum thickness of 1.5mm (0.060”).

.2 Only proprietary adhesives that are specifically accepted by the membrane manufacturer may be used to install Butyl membrane waterproofing systems.

.3 Perimeter fixation for membrane securement (mechanical, adhesive, or adhesive tape), installed to manufacturer’s published specifications, is required for all Butyl waterproofing membranes.

.4 Reinforced flashing (stripping) membranes shall be installed at all horizontal and vertical transitions, deck penetrations, and protrusions (pipes, curbs, drains, sleepers, etc.). Reinforcement flashing membrane must be a minimum thickness1.5mm (0.060”) and shall be fully adhered to substrates.

5.2.3 Thermoplastic Membranes

.1 PVC (Polyvinyl Chloride) single ply thermoplastic waterproofing membranes shall be reinforced, must be fully adhered to acceptable substrates, and shall be a minimum thickness of 1.5mm (0.060”).

.2 Only proprietary adhesives that are specifically accepted for use by the membrane manufacturer may be utilized to install PVC thermoplastic waterproofing membranes.

.3 Perimeter fixation for membrane securement (mechanical, adhesive, or adhesive tape), installed to manufacturer’s published specifications, is required for all PVC thermoplastic waterproofing membranes.

.4 A reinforced flashing (stripping) membrane shall be installed at all horizontal and vertical transitions as well as deck penetrations (pipes, curbs, drains, sleepers, etc.). Reinforcement flashing membranes must be fully adhered to acceptable substrates and shall be a minimum thickness of 1.5mm (0.060”).

5.2.4 Hot Fluid -Applied, Rubberized Asphalt Membrane

.1 Hot Fluid-Applied, Rubberized Asphalt membrane systems shall consist of a minimum of two coatings; the first coat shall be a minimum of 90 mils thick and the second coat a minimum of 125 mils thick. A continuous reinforcement scrim of a minimum 1.35 oz/square yard spun bonded polyester fabric shall be firmly embedded into the first coating of hot rubberized asphalt while installation EVT.

.2 All construction joints, minor concrete cracks and deck cover board joints shall receive a pre-treatment of 90 mil thick coating of hot rubberized asphalt and reinforcement fabric prior to the first membrane coating. Coating and fabric reinforcement shall span a minimum of 75mm (3”) beyond the extent of minor cracks and joints.

.3 A reinforced flashing (stripping) membrane, elastomeric, plastomeric or modified bituminous, shall be installed at all major cracks, horizontal and vertical transitions as well as deck penetrations and protrusions ( pipes, curbs, drains, sleepers, etc.). Elastomeric and plastomeric reinforcement flashing membranes shall be a minimum thickness of 1.5mm (0.060”). Modified bituminous reinforcement flashing membranes shall be a minimum thickness of 3mm and be equal to 180g/meter squared polyester or equal strength composite reinforcement.

.4 A layer of asphalt core protection board or SBS modified bituminous membranes shall be installed to all vertical and horizontal surfaces and must be firmly embedded into the second coating of hot rubberized asphalt while above installation EVT. Asphalt core protection board shall be a minimum thickness 4.5 mm (3/16"). Alternately, an SBS Modified bituminous granulated cap sheet, with a sanded bottom surface that is minimum thickness of 3.7 mm and is reinforced with minimum 180g/meters squared polyester or equal strength composite reinforcement may be used as the membrane protection layer. Composite reinforcement (fibreglass/polyester) membranes are strongly recommended when membranes are embedded in hot rubberized asphalt as their physical properties are more dimensionally stable than membranes reinforced with polyester only.

6 PERIMETER FLASHING: MEMBRANES

6.1 General

6.1.1 MEMBRANE FLASHING - Bituminous Elastomeric & Plastomeric

.1 Membrane flashing (stripping) details with the exception of low parapets, planter wall pre-curbs, and low door sill details must be designed to provide a minimum 200 mm (8") sealed height above the waterproofing membrane and not less than 100mm (4”) above the waterproofing system finished surface. Finished surface is defined as the top of the waterproofing assembly, be it concrete pavers, ballast, unit masonry, or growing medium (soil), etc. Refer to Section 9 Construction Drawings

.2 Doorsill flashing membranes (stripping) may be less than 200 mm (8") in height but shall not be less than 100 mm (4") above the primary waterproofing membrane and must be installed to comply with the following conditions:

• A metal water stop flashing, formed with pan folded, welded or soldered corners must be mechanically attached to inside of doorsill framing or opening and be sealed with membrane flashing (stripping).

• Membrane flashing, (stripping) or metal pan sill flashing must be installed at doorjamb framing or opening to a minimum height of 100 mm (4") above doorsill framing or opening, prior to installation of doorjambs and doorsills. Membrane gussets must be installed at sill corners.

• Metal pan sill flashings or RGC accepted reinforced liquid flashing systems must be installed wherever clearances preclude the use of membrane flashing (stripping) to seal doorsill details.

• Slopes must be provided to direct water away from doorsill details. (Overhangs and overflow drains are recommended wherever practical).

.3 All exterior perimeter walls that have waterproofing terminating at or near the top of walls must have membrane flashing (stripping) that overlaps the exterior finish (i.e. wall cladding) by a minimum of 50 mm (2"). On high parapet walls, that are completely flashed with metal, where membrane flashing (stripping) is terminated part way up the wall (without a reglet detail) the remainder of the parapet shall be covered with a flashing underlay of a minimum 40 mils or 1 mm (.040") self-adhered modified bitumen membrane. No. 15 Felt is not acceptable.

.4 All membrane flashing (stripping) terminating at cladded (i.e. stucco, siding, etc.) walls must lap under the sheathing membrane and cladding by minimum of 75 mm (3"). All walls and up stands shall be covered with sheet metal base flashings.

.5 All membrane flashing (stripping) terminating under a reglet must be sealed to the wall with a compatible mastic and covered with metal flashing that terminates in a reglet.

.6 Where a wall or conventional separation / expansion joint detail intersects with a higher wall; the membrane flashing (stripping) must be sealed by reinforcement gussets (membrane saddles) that are formed to reinforce the inside and outside corners.

.7 New construction projects must follow proper sequencing. Where waterproofing membrane flashings (stripping) overlaps work by others (i.e. siding, stucco, cladding, , etc.) this work shall be complete prior to the installation of metal flashing or wood blocking must be installed to facilitate the future installation of the exterior wall finishes. When flashing membranes lap under work by others (siding, stucco, glazing, cladding, etc.), the membrane and metal flashings shall be installed prior to any wall coverings. Any variance to proper detail sequencing must be approved by the design authority in writing.

7 MEMBRANE PROTECTION

.1 An RGC accepted membrane protection layer(asphalt core board, cap sheet or protection mat), must be installed by the waterproofing contractor, and be compatible with waterproofing membrane. The protection layer shall be installed and secured, as soon as possible, upon completion of waterproofing membrane installation. Construction traffic, by other than waterproofing trade and membrane moisture monitor technicians, is not permitted until the membrane protection layer is completely installed and secured.

9 INSULATION

9.1 General

.1 Only Type 4 or higher density extruded, expanded polystyrene insulation conforming to CAN/ULC-S701 latest addition may be used above waterproofing membranes.

.2 Insulation joints shall be offset or staggered a minimum of 300 mm (12") from adjacent layers and rows.

.3 An accepted drainage layer & filter mat shall be installed on the top surface of extruded polystyrene insulation whenever pavers, gravel ballast, unit masonry or growing mediums (soil) are used as overburdens or wearing courses over waterproofing.

(From 9.0.5 INSULATION)

Extruded expanded polystyrene, conforming to ULC-S701 Type 4 with a compressive strength of 240 kPa (35psi) is the only commercially produced insulation suitable for use over waterproofing and protected membrane roofing systems. Extruded expanded polystyrene is available in a 600mm x 1200mm (2'x4') board size, has an aged R value of 5.0 per inch (RSI 0.87) and ranges in thickness' from 25mm (1") to 100mm (4").

For more information on extruded expanded polystyrene insulation refer to Section 3.6.5 of this manual.

10 DRAINAGE LAYER

10.1 E8 DRAINAGE LAYER

.1 A drainage layer is mandatory between waterproofing membranes, overburdens or wearing courses to provide for free flow of water to drains. Pavers on pedestals provide a subsurface drainage path at the membrane or insulation level and are therefore strongly recommended, whenever practical. Only manufacturer’s proprietary purpose made pedestals, with integral spacer ribs for uniform spacing between pavers, that provided a minimum ventilating air space height of 12.5 mm (1/2”) are acceptable for use with concrete pavers and other unit masonry products. For waterproofing systems with extruded polystyrene insulation the drainage layer shall be placed on the top surface of the insulation.

.2 When manufacturer’s proprietary pedestals are not used for drainage a continuous purpose made manufactured geosynthetic drainage core or geocomposites shall be installed under all overburdens or wearing courses. Geosynthetic drainage cores and geocomposites shall be molded (dimpled) or woven plastic grids, shall be a minimum of 9.5 mm (3/8”) thick or greater, and provide uniform support as well as traffic-bearing properties for overburdens and wearing courses. Only geosynthetic drainage cores and geocomposites with factory laminated filter fabric, which are designed to resist damage from the weight of the specified overburden, are acceptable for use in the RGC Guarantee Program. Refer to the overburden specifications of the project, and membrane manufacturer requirements, when selecting the appropriate material.

.3 Filter fabric (mat) is required for all overburdens that include intrusive materials, growing medium, sand, gravel, mortar, etc. and may be either factory laminated to geocomposites or field installed over geosynthetic drainage cores. Filter fabric shall be installed to a sufficient height at all up-stands, lapped at joints and must be fitted around all penetrations as well as protrusions in order to eliminate the intrusion of overburden and or wearing course materials.

.4 In order to prevent moisture from being driven into extruded polystyrene insulations (water vapour transmission) geosyntheticdrainage board and drainage composites surfaces must not be in direct contact with more than 40% of the insulation board surfaces.

(From 9.0.7 DRAINAGE SYSTEMS & MATERIALS)

Pavers on pedestals promote free subsurface drainage at the membrane the level and are therefore strongly recommended whenever practical. When pedestals are not used as the drainage layer a proprietary geosynthetic drainage core panel is required over waterproofing membranes and is placed above protection boards or extruded polystyrene insulation. Geocomposites and Geosynthetic drainage panels are designed with openings to direct excess subsurface water to deck drains. Proprietary geocomposites and geosynthetic panels must be designed with sufficient compressive strength to support the design load of overburdens as well expected live loads and be acceptable for use by the membrane manufacturer. Geosynthetic drainage cores are typically molded (dimpled) or woven plastic grids, that is a minimum of 9.5 mm (3/8") thick or thicker and is designed to provide uniform support as well as traffic-bearing properties for overburdens and wearing courses. Only geosynthetic drainage cores and geocomposites with factory laminated filter fabric, which are designed to resist damage from the weight of the specified overburden, are acceptable for use in the RGC Guarantee Program. Refer to the overburden specifications of the project, and membrane manufacturer requirements, when selecting the appropriate material.

Filter fabrics (mats) must be installed to a sufficient height at all up-stands, be properly lapped at joints and side laps as well as tightly fitted around all penetrations and protrusions, in order to eliminate the intrusion of overburden or wearing course materials. In order to prevent moisture from being driven into extruded polystyrene insulations drainage board surfaces must not be in direct contact with more than 40% of the insulation board surfaces. (Refer to RGC Guarantee Standards E)

11 WEARING COURSE and OVERBURDEN

.1 The use of concrete pavers on pedestals as an accessible wearing course is strongly recommended whenever practical, over all waterproofing systems. Pavers on pedestals provide space for the unobstructed flow of water to drains and permit reasonable easy access to waterproofing membranes.

.2 Unit masonry, brick, tile or stone placed on sand and or gravel beds as well as intensive garden systems are accessible but more difficult to remove than pavers on pedestals in order to provide reasonable access to waterproofing membranes. Subsequently these overburdens require a moisture monitoring sensor grid on top of the waterproofing membrane in order to locate possible breaches in membranes. Refer to RGC guarantee standard E11.

.3 Inaccessible wearing course designs for pedestrian and emergency vehicle traffic on plaza decks include cast-in place concrete protection slabs (split-slab) and brick, tile or stone set in mortar beds. Subsequently, inaccessible wearing course designs require demolition for access to the membrane and therefore must include an RGC accepted moisture monitoring sensor grid above the membrane to detect as well as locate possible membrane breaches. Moisture scanning grids that are specifically accepted by RGC are listed in Section 2.2 Accepted Materials. Refer to RGC guarantee standard E11. . Solid cast-in place concrete protection slab (split-slab) and asphalt paving wearing courses (inaccessible) shall incorporate surface score lines (indents) to facilitate cutting for removal of wearing course sections in order to locate possible breaches in membranes. Score lines shall be straight edged grid patterns (squares, rectangles, diamonds, etc.) with indents spaced at a maximum of two (2) metres apart.

(From 9.0.6 WEARING COURSES (OVERBURDENS))

CATEGORIES - ACCESSIBLE & INACCESSIBLE

The design of wearing courses for plaza deck waterproofing systems, fall into two basic categories, accessible and inaccessible. Waterproofing Systems for pedestrian and emergency vehicle traffic on plaza decks are often designed with inaccessible wearing or protection courses. In contrast Protected Membrane Roofing Systems on plaza/terrace decks are almost always designed with accessible wearing courses for pedestrian traffic and utilize pavers on pedestals. Accessible wearing courses are reasonably easy to remove for access to the membrane. Inaccessible wearing courses require demolition for access to the membrane and are usually constructed with cast-in-place concrete protection slabs (split-slab) or brick, tile or stone set in mortar beds. As a result of the potential exorbitant costs of demolition to access membranes under inaccessible wearing / protection courses the performance criteria for these waterproofing systems are higher. Subsequently, additional design requirements and installation standards must be followed in order to provide for an anticipated service life equal to that of the structure and for coverage under the RoofStar Guarantee Program a membrane moisture monitoring system is required in order to identify and locate membrane breaches that may occur during the waterproofing systems service life.

Note

RGC strongly recommends the use of wearing surfaces that permit reasonable easy access to the membrane. Waterproofing systems that incorporate inaccessible protection courses in the design such as poured-in-place concrete, asphalt paving and wearing surfaces units set in mortar beds, etc. must meet additional standard requirements for coverage under the RoofStar Guarantee Program. (Refer to RGC Guarantee Standards E)

12 LANDSCAPING, PLANTERS & OTHER VEGETATED OVERBURDENS

.1 For landscaping, planters, gardens and other vegetated overburdens on waterproofing systems strict compliance to RGC Guarantee Standard A5.3 Planters, Landscaped and Green Roofs is mandatory. (Refer to RGC guarantee standards A)

13 MEMBRANE MOISTURE SURVEYS & MONITORING SENSOR GRIDS

.1 A moisture scan survey and report which confirms the water tight integrity of membranes is mandatory for all waterproofing systems prior to installation of inaccessible overburdens or wearing courses that are difficult to remove. Membrane moisture survey scans must be performed by an independent Moisture Detection Company that is specifically accepted by RGC.

.2 With the exception of pavers on pedestals, gravel ballast to a maximum of 75mm (3”) thick), and soil or extensive growing mediums less than 200mm (8”) in depth a moisture monitoring sensor grid (conductance scanning grid) is mandatory and shall be installed on the top surface of all waterproofing membrane systems designed with overburdens and wearing courses. Moisture monitoring sensor grids shall be installed prior to installation of overburdens or wearing courses and may be placed over protection boards or SBS membranes that have been set in hot fluid-applied modified asphalt.

.3 Scanning sensor grids on waterproofing systems with reasonably accessible overburdens such as unit masonry, bricks, stone and pavers on sand or gravel beds as well as soil or intensive growing mediums more than 200mm (8”) in depth, shall be spaced on a grid of a maximum of three (3) meters in any direction. The scanning sensors grid must cover the entire deck surface, shall be carried to a minimum of 50mm (2”) in height at all vertical transitions as well as deck perimeters, penetrations and protrusions.

.4 Scanning sensor grids on waterproofing systems with inaccessible overburdens such as concrete pours (split –slab), asphalt paving, unit masonry ( bricks, pavers and stone) set in mortar beds shall be spaced on a grid of a maximum of two (2) meters in any direction. The scanning sensors grid must cover the entire deck surface, shall be carried to a minimum of 50mm (2”) in height at all vertical transitions as well as deck perimeters, penetrations and protrusions.

.5 Flood Testing is not a recommended practice but is at the discretion of the design authority or owner. If flood testing is required to water test waterproofing membranes, testing shall be conducted prior to installation of insulation and overburdens and be performed to ASTM D5957 – 98.

14 PENETRATIONS and DRAINS

14.1 General

.1 Clearances (Waterproofing) Deck penetrations, pipes, curbs, drains, etc. shall NOT be installed less than 200 mm (8") from one another or the base of walls and other construction details unless specifically authorized by the inspection agency as a special condition. These items are to be located by others.

.2 Penetration Flashings (Waterproofing) Curb mountings for all venting units, equipment, pipes and cables on waterproofing decks are strongly recommended. Curbs are to be supplied and installed by others. Curbs are to be a minimum 200 mm (8") sealed height above the waterproofing membrane and not less than 100mm (4”) above the waterproofing system finished surface (overburden). Only purpose made non-ferrous metal strip-in type vents will be permitted for use with waterproofing systems.

.3 Pipes, cables and multiple roof penetrations; including grouped pipes and or cables must incorporate purpose made weather head seals. Purpose made multiple penetration weather head seals must provide a positive weather seal by use of metal hoods, manufacturer’s proprietary rubber based friction seals, mechanical clamps or gooseneck type designs. Gum boxes or pitch pans are not permitted for use with waterproofing systems. (Refer to Section 9 Construction Drawings)

14.3 Drains and Scuppers

.1 The use of bi-level drains with adequate openings for both surface and subsurface drainage are mandatory for all inaccessible waterproofing systems that utilize interior drainage systems with low permeable wearing courses (poured concrete, bricks, unit masonry and stone set in mortar beds).

.2 Membrane flashing reinforcement is required for drains and other roof accessories and is to be installed as per waterproofing membrane manufacturer’s published application instructions.

.3 When cast-iron drains are used; a sump receiver and under-deck clamp must be provided and installed by the trade supplying the deck drain.

.4 All flange type drains as well as flow through wall drains and scuppers shall be constructed of non-ferrous materials.

.5 On all waterproofing projects all drains connected to internal piping shall be connected by mechanical compression type seals only. “O”- rings, mastics and caulking are not acceptable methods to seal drains to internal piping.

15 PERIMETER FLASHINGS: METAL

15.1 General

.1 Sheet metal material and installation methods for waterproofing projects must comply with following Guarantee Standards:

• A6.7 Sheet Metal Material Standard
• A6.8 Metal Flashing Seams
• A6.9 Metal Cap / Base Flashings and Reglet
• A6.10 Mechanical Attachment of Metal Cap Flashings.

15.6 Cap Flashings, Base Flashings and Reglets

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Waterproofing Plazas, Promenades and Terraces

Accepted Materials