Template:Part 9 (Waterproofing Roofs - PVC)

See more information on Waterproofing Materials in Division B: Essential Elements.

1 General

Application methods for single-ply membranes commonly include the following:

1. Mechanically fastened:
   1. In-seam fastening
   2. Induction weldedv
   3. Bar and cover securement
2. Adhered:
   1. Self-adhering (typically membranes with an adhesive backing covered by a release film that protects the adhesive from contamination; release films are removed at the time of installation).
   2. Adhesive-applied (using synthetic adhesives that are rolled or brushed onto the membrane and the substrate).
   3. Hot bitumen adhered (sometimes referred to as 'hot-mopped', 'hot-applied' or simply 'mopped', this application method is used with fleece-backed membranes).
3. Loose-laid and ballasted.

1.1 Design

1.1.1 RoofStar 15-Year Guarantee

1. Refer to 1.3.1 RoofStar 15-Year Guarantee for general requirements, to qualify the project for a RoofStar 15-year Guarantee.
2. See Table 9.1 for membranes and application types that qualify for a RoofStar 15-Year Guarantee.

1.1.2 All Projects

1. All single-ply membrane roofs shall meet the requirements of the Code and the RoofStar Guarantee Standards, and shall be (when applicable)
   1. a Tested Assembly.
   2. an Assembly with Proven Past Performance.
   3. an assembly with custom-engineered securement.

   
   See also 3 SECURING the ROOF ASSEMBLY.

2. The specifications, details, and installation techniques must conform to the membrane manufacturer's requirements, unless exceeded by these Standards.
3. Membranes must be selected for their
   1. performance characteristics in relation to the intended use of the roof, as for example puncture resistance or reflectivity and reduced heat absorption.
   2. application methodology, which may be limited by
      1. the type of supporting deck or substrate to which it will be applied.
      2. Overburden (Only PARS and AARS assemblies are permitted when a Conventionally Insulated System, or a portion of it, is designed to support any type of load; pavers supported by pedestals are an exception. This is subject to the limitations and standards in 14.1.2 Design).
   3. compatibility with chemicals or other contaminants including, without limitation,
      1. animal or vegetable grease.
      2. hot pipes (release valves).
      3. petroleum products or biproducts.
      4. miscellaneous fluids, detrimental to the membrane.
      5. pool or garden chemicals and fertilizers.
      6. pet urine.
      7. bird excrement.
      8. refrigerants.

   
   Membranes should be protected from contamination. Consult the membrane manufacturer for their advice and recommendations.

4. An intermediate separation layer must be installed between all fully adhered membranes and rough deck surfaces in a Protected Membrane Roof System.
5. Membranes
   1. must be fully adhered when specified for a Protected Membrane Roof System. See also 1.6 RoofStar Guarantee: Coverage and Limitations.
   2. may not be adhered directly to a
      1. concrete deck (this Standard does not apply to accepted hot-mopped membranes, or to membranes adhered to concrete walls).
      2. wood deck.
6. When a Conventionally Insulated System will be accessed at least once per month for maintenance of serviceable equipment, the design must incorporate designated walkways
   1. to protect the primary membrane at roof access points, equipment service locations and along travel routes.
   2. that facilitate drainage and drying (pedestals and other paver supports provide airflow for drying surfaces and assist in leveling; they should not impede the flow of water or air and should uniformly distribute the dead load of pavers and predicted live loads).
   3. that are properly secured against movement by wind.
   4. that may be constructed with
      1. accepted concrete-topped XPS insulation panels.
      2. pavers placed on
         1. purpose-made pedestals or rubber pads (slip sheets under pedestals may be necessary to prevent membrane abrasion).
         2. drainage mats.
         3. XPS insulation panels with drainage grooves or channels.
      3. proprietary walkway membranes installed in segments.
      4. A proprietary coating.

      
      See also 1.6 RoofStar Guarantee: Coverage and Limitations.

7. Fall protection warning zones (see WorkSafeBC Regulations and related materials) may be designed to utilize
   1. a proprietary self-adhering tape.
   2. a proprietary coating.
8. Installed membranes must be protected from damage caused by work performed concurrently or subsequently by other trades. The Design Authority is strongly urged to direct the work of other trades through specific, explicit directives in the design specifications.

2 Materials

See Single-ply Waterproofing Roof Membranes accepted for RoofStar-guaranteed roof systems. See also Part 3 SECURING the ROOF ASSEMBLY for special requirements concerning membrane roofs.

2.1 Composition, Thickness and Selection

1. Membranes must be selected from the Accepted Materials, and each membrane must conform the minimum requirements outlined in Table 9.1.
2. Liquid membranes must be reinforced and accepted for use both by the single ply manufacturer and by the manufacturer of the liquid membrane.

Table 9.1 PVC Membranes: RoofStar 5, 10 & 15-year Guarantees
Applies to Field and Flashing membranes. All thicknesses shown are in mm (membrane only, no fleece)

		Exposed Roof Systems						Protected Roof Systems		Grade-level Water- proofing
		Conventionally Insulated / Uninsulated Systems				Built-in Gutters		Ballasted	PMR Systems
		Mechanically Fastened; Induction Welded*	Adhered			Adhesive- applied; Self- adhered		Loose-laid	Adhered	Adhered
			Self- adhered	Hot- mopped	Adhesive- applied
Type, Reinforcement, Grade	Guarantee Term	mm (mils)	mm (mils)	mm (mils)	mm (mils)	mm (mils)		mm (mils)	mm (mils)	mm (mils)
PVC
	5	1.270 (50)	X	1.270 (50)	1.270 (50)	1.524 (60)		1.270 (50)	1.270 (50)	1.524 (60)
	10	1.524 (60)	X	1.524 (60)	1.524 (60)	1.524 (60)		1.524 (60)	1.524 (60)	1.524 (60)
	15	2.032 (80)	X	2.032 (80)	2.032 (80)	2.032 (80)		X	2.032 (80)	X

*Induction welding subject to the securement requirements in the applicable membrane Standard, Part 3.

2.2 Fasteners and Adhesives

1. Unless otherwise specified in these Standards, fasteners used to secure the membrane must be the fasteners specified by the membrane manufacturer or, when a fastener is not specified, a #14 screw-type fastener or impact-driven fastener compatible with all secured materials.
   
   See 3.2.3 Fasteners and Adhesives for attachment requirements.
2. Only Type 3 or 4 oxidized asphalt or Type 3 or 4 SEBS modified asphalt is permitted for installation of hot-applied membranes.

2.3 Accessories

1. All materials, including but not limited to securement strips, primers, adhesives, sealants, cleaners and membrane flashings, that comprise the roof system must be supplied or accepted by the membrane manufacturer.

3 Application

3.1 General

3.1.1 RoofStar 15-Year Guarantee

1. Refer to 1.3.1 RoofStar 15-Year Guarantee for general requirements, to qualify the project for a RoofStar 15-year Guarantee.
2. T-joints must be covered with a proprietary cover sealed along all edges with the membrane sealant, or with a field-fabricated cover fit to extend past the intersecting membranes 100 mm (4”), using unreinforced PVC covers.

3.1.2 All Projects

1. Membranes must be installed according to the manufacturer's published instructions, details and installation techniques unless exceeded by this Standard.
2. An intermediate separation layer must be installed between
   1. PVC membranes and foam plastic insulation materials (because of chemical incompatibility).
   2. all fully adhered membranes and rough deck surfaces in a Protected Membrane Roof Systems.
3. Membranes must be
   1. unrolled and allowed to ‘relax’ for at least thirty (30) minutes prior to installation.
   2. conditioned in keeping with the membrane manufacturer’s guidelines for storage and cold weather application.
4. Conventionally Insulated Systems must be
   1. temporarily and continuously sealed, at the end of a day, or when installation must be stopped because of circumstance (such as inclement weather), to envelope any other components enclosed below the membrane system.
   2. positively lapped, wherever possible.
5. All membranes must be mechanically secured
   1. around the perimeter.
   2. at a slope change greater than 1:6 (2" in 12").
   3. around all curbs.
   4. at all drains and protrusions (mechanically fastened systems only).

   
   Securement spacing must conform to the membrane manufacturer’s published requirements, unless exceeded by these standards. See also Part 3 SECURING the ROOF ASSEMBLY.

6. Field test welds must be performed on a daily basis, prior to welding, and thereafter at 2-hour intervals. When welding commences before the field Observer can verify the field test weld, a cut test may be required.
7. All field membrane seams must be
   1. clean and dry.
   2. fully rolled.
   3. free of fish-mouths.
   4. installed so that any membrane laps are located at least 900 mm (36”) from the centre of any roof field drain, except where drain sumps are employed.
   5. installed so that they overlap adjacent membranes (side laps) at least 150 mm (6”) where in-seam fasteners are used, extending beyond the fastener plate by at least 50 mm (2”).
   6. sealed
      1. at least 38 mm (1 ½”) wide using a robotic welder, and seams probed to verify a consistent bond.
      2. at least 50 mm (2”) wide using a hand-held welder, and seams probed to verify a consistent bond.
      3. with visible, continuous edge sealant (when required by the membrane manufacturer).
   7. covered at T-joints with a proprietary cover sealed along all edges with the membrane sealant, or with a field-fabricated cover fit to extend past the intersecting membranes 50 mm (2”), using unreinforced PVC covers.
8. All installed membranes must be protected from
   1. damage by traffic and other trades.
   2. splashed or dripped primer. This standard also applies to work by other trades, who may use primers for self-adhering membranes typically installed on walls or around doors, windows or other wall penetrations.

3.2 Material Storage and Handling

1. All uninstalled materials must be
   1. protected from weather.
   2. stacked above ground or the roof surface in packaging provided.
   3. approved or recommended by the manufacturer.

3.3 Mechanically Attached Membranes

1. Whenever possible, orient mechanically-fastened membranes perpendicular to steel deck flutes in order to distribute fasteners across the deck.
2. To secure the membrane, use fasteners and stress plates, or a proprietary securement bar, that are
   1. specifically designed for the application of the specified and installed membrane, or are
   2. listed in the Tested Assembly report as an acceptable alternative (substitutions, without the written consent of the primary membrane manufacturer, are not permitted and may void the RoofStar Guarantee).
3. Unless otherwise listed in the assembly components of a Tested Assembly, membranes shall be fastened with self-drilling purpose-made #14 screws having a deep-recessed head.

3.4 Loose-laid Ballasted Membranes

1. Loose-laid membranes held in place with gravel ballast must
   1. meet the thickness requirements in 9.2.1 Composition, Thickness and Selection.
   2. be installed
      1. according to the membrane manufacturer’s published instructions.
      2. over smooth, flat and clean substrates that are free of protrusions and foreign matter.
   3. not be installed over mechanically fastened substrates or hard-surfaced overlays.

3.5 Adhered Membranes

3.5.1 General

1. Fully adhered single-ply membranes must not be installed directly to a supporting wood or concrete deck structure, but may be applied over a RoofStar-accepted deck overlay suitably fastened to the deck.

3.5.2 Self-adhered and Adhesive-applied Membranes

1. Self-adhering membranes must be
   1. applied to a suitable, clean, dry substrate and in keeping with the manufacturer’s published instructions.
   2. installed only when the ambient air temperature meets or exceeds the temperature permitted by the manufacturer.
   3. installed over a primed membrane lap, when required by the manufacturer.
   4. fully rolled or broomed, as required by the membrane manufacturer, to ensure even, full contact with the substrate. Air bubbles should be avoided, and must fall within the permissible tolerances provided by the membrane manufacturer or the Tested Assembly.
2. Adhesive-applied membranes must be
   1. applied to a suitable, clean, dry substrate and in keeping with the manufacturer’s published instructions.
   2. installed only when the ambient air temperature meets or exceeds the temperature permitted by the manufacturer.
   3. installed with bonding adhesive evenly applied to both the substrate and the membrane, and allowed to dry to the touch, or as otherwise specified by the membrane manufacturer.
   4. fully rolled or broomed, as required by the membrane manufacturer, to ensure even, full contact with the substrate. Air bubbles should be avoided, and must fall within the permissible tolerances provided by the membrane manufacturer or the Tested Assembly.
3. End laps must be sealed in keeping with the membrane manufacturer’s published instructions. When a cover strip is required, refer to the standards in 9.3.1.2 All Projects.

3.5.3 Hot Asphalt-adhered Membranes

1. Only fleece-backed membranes may be installed with hot asphalt.
2. All concrete decks to receive adhered membranes must be primed with the membrane manufacturer’s asphaltic primer.
3. Asphalt
   1. temperature must be at least 205°C (400°F), but must conform to the membrane manufacturer’s requirements.
   2. should be mopped no more than 1 m (3') ahead of the roll.
   3. application rates may vary depending upon the substrate, and therefore the rates must follow the manufacturer’s published instructions.

3.7 Membrane Walkways and Warning Zones

See also Part 14 The ROOF as a PLATFORM for design, material and installation requirements when using elevated pavers or other walkway materials.

1. When pavers are used as the walkway material, they must be
   1. spaced no closer than 3mm (1/8″).
   2. supported by non-abrasive pads or proprietary pedestals providing a minimum of 12.7 mm (1/2″) of vertical separation layer for airflow and leveling (slip sheets under pedestals may be necessary to prevent membrane abrasion).
   3. secured against movement by wind, as required.
2. Self-adhering tapes that are applied on top of the primary membrane, to serve a warning zone, must be
   1. acceptable to the manufacturer of the primary membrane.
   2. installed
      1. on a clean, dry membrane.
      2. according to the published instructions of all manufacturers concerned.
3. Tapes used to demarcate zones on the roof are excluded from coverage under the RoofStar Guarantee. Refer to 1.6 RoofStar Guarantee: Coverage and Limitations.