Firestone SBS Membrane Installation Guidelines

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Firestone SBS Membrane Installation Guidelines

Notice to the Reader:

The instructions provided below are reprinted from the manufacturer's own materials which were submitted to the RoofStar Guarantee Program for inclusion in this Manual. The reader is urged to check these against current publications issued by the manufacturer, to ensure accuracy.

Manufacturer: Firestone Building Products

Contact Address: See Membership List in Section 1.

Product Group: SBS MODIFIED BITUMINOUS MEMBRANES

Country of Origin: U.S.A.

Year First Installed
BC: 1998
Canada: 1993
Foreign: 1993

1 Description

Firestone developed prefabricated sheet membranes in 1987 and introduced SBS Modified Bitumen’s in 1991, producing an elastomeric blend with exceptional elongation recovery characteristics. Reinforcing mats consisting of polyester, fibreglass and a combination thereof, are saturated and coated with SBS elastomer modified bitumen to produce roof membranes designed for use in a variety of roof systems. Firestone manufacturers a variety of membranes, each of which is designed to meet the requirements of a variety of roof constructions. The “SBS” and “SBS FR” membrane series are designed to meet the structural, climatic and design needs of a range of applications. These membranes are available with a variety of surfacing materials including; ceramic granules, polypropylene film or sand. Depending on the back surfacing, the membranes may be installed in hot asphalt, in asphalt cold process adhesive, by heat welding or peel and stick self-adhesive. Ceramic granules for cap sheets are available in several colours. If high reflectivity is required, UltraWhite membranes are covered with granules having an initial solar reflectance of 0.72 and an initial thermal emittance ranging from 0.84 to 0.92. The solar reflectance index (SRI) of the UltraWhite membranes range from 87 to 89 as per ASTM E 1980-01.

1.1 GENERAL

The roofing assembly / material information published by the RCABC Roofing Practices Manual does NOT represent a complete set of the manufacturer’s published data, nor does it represent a detailed specification. The preparation of a detailed specification is the responsibility of the design authority.

SYSTEM DESCRIPTION

  1. Two-ply roof membranes: The first ply consists of a base sheet, which may be applied in hot asphalt, asphalt cold process adhesive, fully heat welded, mechanically attached or self-adhered with a heat welded cap sheet. The second ply consists of a cap sheet applied in hot asphalt, cold process adhesive or by heat welding.


COMPOSITION

  1. SBS Compound: When a compatible bitumen is modified by the addition of SBS polymer, the combination provides the desirable properties necessary to ensure the long term performance of the completed roof system. Compatibility of the components, proper mixing and finished product preparation are ensured by production quality control and follow-up testing which ensures long term performance. These properties may be obtained only with a suitable SBS / bitumen compatibility and proper preparation.


The compound in a roofing sheet provides:
  • Waterproofing
  • Elasticity
  • Aging performance
  • Flexibility
  1. Reinforcement: The reinforcement of an SBS modified sheet provides enhancement to the compound. Polyester mat provides puncture resistance, toughness and dimensional stability upon which an SBS roof system depends for performance. A roof system relies upon the combination of compound flexibility and reinforcement toughness to resist hail and foot traffic damage. Polyester allows the SBS membrane to flex and recover while retaining its strength and toughness.
  2. Aging: The aging properties of an SBS modified sheet are dependent on SBS / bitumen blend and the chemistry of the system. All roof systems experience heat exposure. Quality SBS modified bitumen blends age much more slowly than conventional blown asphalt.
  3. Thickness: The aging properties of an SBS modified sheet are influenced by thickness. Thicker sheets age more slowly. Heat welded membranes should have a minimum back coating thickness of 1 mm asphaltic compound.


DELIVERY, STORAGE AND HANDLING

  1. All materials must be stored out of the weather in a clean, dry area in the original packages with the manufacturer’s labels intact.
  2. All materials must be stored on end at a minimum of 4ºC (40ºF) and a maximum of 60ºC (140ºF).
  3. If materials are stored temporarily, they must be stored on end, elevated from the roof surface or the ground, on a pallet and covered by a light colored opaque tarp.
  4. Materials stored on the roof must be stored in a safe matter not to exceed the allowable live load of the storage area.
  5. Care must be taken when transporting and handling Firestone SBS rolls to avoid physical damage.
  6. Isolate Firestone modified bitumen sheets from contact with waste products, petroleum products, grease, oil and animal fats.


SITE CONDITIONS

  1. Slope: Roof slopes which exceed ½" in 12" (4.2%) require the following:
    • he building owner or the design professional intending to specify back-nailing should consider geographic location, specific job conditions, accepted area application practices and the type and grade of materials specified when creating an actual specification for a project.
    • When the slope of the roof exceeds ½" in 12" (4.2%) and hot asphalt attachment is specified, Firestone requires Firestone SBES Mopping Asphalt or CSA A123.4, Type III (3) asphalt be used.
  2. Contact Firestone Roof Systems Solutions Group for additional requirements regarding roof slopes over 3" in 12" (25%).
  3. For roof slopes up to and including ½" in 12" (4.2%), the side laps can be installed parallel or perpendicular to the slope.
  4. For roof slopes greater than ½" in 12" (4.2%), the membrane must run parallel to the slope and be back-nailed.
  5. For non-nailable decks and nailable decks with insulation, the cap sheet must be cut to conform to the spacing of nailers. Using capped nails, nail the end lap across the width of the sheet, with the first nail spaced ¾" (19 mm) from the leading edge of the sheet. The remaining nails are to be spaced approximately 3" (76.2 mm) on centre. The nails should be staggered across the width of the nailer. Firestone fasteners and plates may be used in lieu of cap nails. Four per end lap are required.
  6. For nailable decks with no insulation, the cap sheet must be cut to conform to nailer spacing. Using capped nails or Firestone fasteners and plates, nail the end lap across the width of the sheet, with the first nail spaced ¾" (19 mm) from the leading edge of the sheet. The remaining nails are to be spaced approximately 3" (76.2 mm) on centre. The nails should be staggered across the width of the nailer. Firestone fasteners and plates may be used in lieu of cap nails. Four per end lap are required.
  7. Cap nails must have 1" (25.4 mm) diameter heads with steel head only. The shank must be minimum 11 gauge (2.3 mm) annular ring or spiral shank and be FM approved.


BACK-NAILING REQUIREMENTS FOR SLOPED ROOFS
Cap Sheet Attachment Base Sheet Attachment < ½"
(4.2%)		 > ½" < 1"
(4.2 - 8.3%) 		>1" < "
(8.3 - 16.7%) 		>2" <3"
(16.7 - 25%)
Gravel Surfaced BUR Hot asphalt     NFR NFR Nailers
20" oc		 Nailers
12" oc
Smooth Coated BUR Hot asphalt     NFR NFR NFR Nailers
20" oc
Any Applicable Smooth or Granule Firestone SBS Cap Hot asphalt Any Applicable Firestone Base Sheet Hot Asphalt or Mechanically Attached NFR Nailers
32" oc		 Nailers
32" oc		 Nailers
16" oc
Full Length Sheet Full Length Sheet % Length Sheet
Any Applicable Smooth or Granule Firestone Cap Sheet Firestone Multi-Purpose MB Cold Adhesive Any Applicable Firestone Base Sheet Heat Fused, Hot Asphalt, Mechanically Attached or Firestone Multi-Purpose MB Cold Adhesive NFR NFR NFR Nailers
32" oc
Full Length Sheet
Any Applicable Smooth or Granule Firestone Cap Sheet Heat fused Any Applicable Firestone Base Sheet Self-Adhesive, Heat Fused, Hot Asphalt, Mechanically Attached or Firestone Multi-Purpose MB Cold Adhesive NFR NFR NFR Nailers
32" oc
Full Length Sheet
Refer to Firestone MB-LS-9 for detailed back-nailing requirements.
NFR - No fastener required at this slope.


Wood decks: Plywood, OSB and Wood Plank

  1. Firestone requires that wood planks be yellow pine with a minimum ¾" (19.1 mm) thickness. The installation of a ply of sheathing paper (by others) is required under the nailed base sheet.
  2. Firestone requires that plywood have a minimum thickness of ½" and that OSB decks have a minimum 7/16" (10.5 mm) thickness.
  3. The Firestone base sheet or cap sheet may not be adhered directly to a wood substrate. The cap sheet and / or the base sheet must be adhered to an acceptable insulation, coverboard or a mechanically attached base sheet.
  4. When mechanically attaching insulation or base sheets, wood decks are required to have a fastener pullout of 300 lb. (1.8 kN) per fastener.
  5. When nailing a base sheet, wood decks are required to have a fastener pullout of 40 lb. (0.24 kN) for cap nails per fastener.


BASE SHEET AND INSULATION ATTACHMENT FOR PLYWOOD, OSB AND WOOD PLANK ROOF DECKS
Acceptable Fasteners for Insulation
and Base Sheet Attachment		 Acceptable Insulation Adhesives
Firestone Heavy Duty
Firestone All Purpose
Belted Fasteners		 1" (25.4 mm) into or through deck Firestone ISO SPRAY
Firestone ISO FIX
Firestone ISO Twin Pack


Steel decks

  1. Firestone recommends that the steel deck be a minimum 22 gauge (0.76 mm).
  2. Factory Mutual Research - Approved steel decks are currently available in 22 gauge (0.0295", 0.794 mm), 20 gauge (0.0358", 0.909 mm) and 18 gauge (0.0474", 1.204 mm) thick sheet with 1.5" (38 mm) deep corrugations. The corrugations (ribs) are cold rolled in the sheets. The deck has a 6" (152 mm) module, that is, the ribs are 6" (152 mm) on centre. All fastening approvals and recommendations are based on this profile. (Approved and recommended spacings are such that the fasteners will engage the top flange of the deck). Another common configuration is 3" (76 mm) deep deck, which usually has an 8" (203 mm) module.
  3. When mechanically attaching insulation, steel decks are required to have a fastener pullout of 300 lb. per fastener.
  4. The Firestone base sheet or cap sheet may not be adhered directly to a steel deck. The cap sheet and / or the base sheet must be adhered to an acceptable insulation or coverboard.
  5. On steel decks, the edges of insulation boards running parallel with the deck are required to be supported by the top flange of the metal deck. The board should have a minimum 1.5" (38.1 mm) bearing on the steel deck flange. Cantilevering insulation boards over deck flutes can fracture insulation boards, reducing the support for the membrane, making it susceptible to puncture.
  6. If present, it is required that phenolic insulation be removed. Once removed, a visual inspection of the deck condition and other components is required. It is the building owner or his design professional’s responsibility to determine the condition of the deck. All deteriorated components must be replaced as necessary.


INSULATION ATTACHMENT FOR STEEL DECKS
Acceptable Insulation Fasteners Acceptable Insulation Adhesives
Firestone Heavy Duty
Firestone All Purpose
Belted Fasteners		 ¾" (19 mm) through deck Firestone ISO SPRAY
Firestone ISO FIX
Firestone ISO Twin Pack


Chemical Incompatibility

  1. SBS modified bitumen products are not compatible with coal tar pitch and not resistant to oil and petroleum products.


Roof Deck Overlay

  1. Acceptable roof deck overlays include plywood, Dens Deck or a minimum No. 40 glass-ply felt (CSA A123.2-M, Type CF).


Insulations

  1. Modified bitumen can be used with most common insulations used for roofing and installed according to RoofStar Guarantee Standards.


Minimum Asphalt Temperature

  1. The minimum temperature for mopping asphalt is +205ºC (+400ºF) at the point of application.


Adhesive Application

  1. Adhesives are intended to adhere the membrane to the substrate or as inter-ply adhesive to adhere membranes to themselves.

STANDARDS AND APPROVALS

(for specific membranes or assemblies consult Firestone)
  1. American Society for Testing and Materials: D6163 & D6164 (Grade, Type and Class vary with membrane).
  2. Underwriters Laboratories: Class A, B, C.
  3. Underwriters Laboratories of Canada: Referenced to UL.
  4. Factory Mutual: Class 1 Fire and I-90 or greater.


MANUFACTURER’S SERVICES

  1. Applicator Training: Firestone membranes are applied by approved applications.
  2. Technical Service: Technical representatives are available for consultation and field training; owners, architects and engineers are assisted in the selection and proper use of materials by technical representatives.
  3. Specification / Drawings: Complete specifications and detail drawings are available upon request and on the Firestone website.

1.2 MATERIALS

NOTE: Regardless of the materials listed below or anywhere else in these manufacturer's guidelines, only materials accepted for use in the RoofStar Guarantee Program, or accessories associated with those materials, may be used to qualify for a RoofStar Guarantee. To see a list of the manufacturer's products accepted for use in the RoofStar Guarantee Program, click on the link above.

1.3 EXECUTION

PREPARATION

  1. Apply roofing materials over clean, dry surfaces in accordance with good roofing practices of the RoofStar Guarantee Program.
  2. Ensure that moisture and contaminates are completely removed from the substrate prior to membrane application.
  3. Prime all metal flashings to be installed in the membrane and allow primer to dry prior to installation.
  4. Use only compatible primers and adhesive, mastics or sealants.
  5. Provide adequate protection against fire, particularly when using propane torch-applied membranes.
  6. Torch base sheets to approved substrates only.


INSULATION

  1. Mechanically fasten insulation over nailable decks, in accordance with RoofStar Guarantee Standards.


APPLICATION INSTRUCTIONS FOR A TWO-PLY SYSTEM

  1. Beginning at the low point of the roof, apply the membrane base sheet to the substrate using a minimum side lap of 3" (76 mm) and an end lap of 6" (150 mm). Stagger end joints. Terminate the base sheet at the top of the cant strip. Do not adhere base sheet to cant strip.
  2. Beginning at the low point of the roof, fully adhere the cap sheet to the base sheet. Side laps must be a minimum of 3" (76 mm) and end laps must be a minimum of 6" (150 mm). Position base sheet laps so that the distance between base sheet laps and cap sheet laps shall not be less than 12" (300 mm).
  3. Stagger end laps from course to course so that at no end lap will be closer than 12" (300 mm) from the preceding and succeeding end lap.
  4. Provide a smooth application, free of air pockets, wrinkles, fishmouths or tears.


JOB SITE CONSIDERATIONS

  1. During the construction process, the roofing contractor is responsible for ensuring that all components of the Firestone roof system, including the finished areas are protected from damage, including, but not limited to:
    • Damage that may result from the continued construction process.
    • Discharges such as petroleum products, greases, oils (mineral and vegetable), animal fats and other by-products.
    • Direct contact with continuous steam or heat sources when the in-service temperature is in excess of 60ºC (140ºF).
  2. All safety regulations required by agencies having jurisdiction must be followed.
  3. Refer to the Firestone Technical Information Sheet "Recommended Guidelines for Working on an Occupied Building" for specific guidelines when installing adhesives or asphalt products on an occupied building.
  4. Cold weather conditions:
    • When the outside temperature is below 4.4ºC (40ºF), installation of the Firestone roof system may required additional application precautions:
    • For a minimum of 24 hours before installation, adhesives and sealants should remain in an environment between 15.5ºC (60ºF) and 26.6ºC (80ºF).
    • Materials should be used within four hours of removal from a heated storage area. If materials area not used within that time period, they should be returned to the heated storage area until the temperature of the material returns to the temperature of the heated storage are. Typically, this is 24 hours.
    • Certain products may be damaged when allowed to freeze. Do not use any products that have been frozen without written permission from Firestone.
    • Refer to the product Firestone Technical Information Sheet (TIS) for application and temperature restrictions.
  5. For additional information and guidelines, see the Firestone Asphalt Roofing Application Guide and the CRCA Roofing and Waterproofing Manual.


ASPHALT PRODUCTS

  1. Assure that all health and safety measures are followed when installing hot asphalt to protect the installers as well as the occupants of the building. Assure compliance to all building codes and safety regulations when using hot asphalt.
  2. Asphalt for installing the flashings and / or the roof membrane base sheet, base plies and cap sheets must be Firestone SBES Mopping Asphalt or either CSA A123.4, Type III (3) or Type II (2). Asphalt selection must be suitable for roof slope. All asphalt must be tested in accordance with ASTM D 312 and be certified by the supplier that it meets the minimum requirements for the specific type.
    • Mopping asphalt must never be heated above the flashpoint temperature.
    • Mopping asphalt must never be heated above the finished blowing temperature for more than 4 hours.
  3. Asphalt Primer: Asphalt primer must meet the requirements of ASTM D 41.
  4. When hot asphalt is required, Firestone requires that Firestone SBES Mopping Asphalt or CSA A123.4, Type III (3) asphalt be used.
    • In all SBS systems.
    • Where the slope exceeds ½" in 12" (4.2%).
  5. Asphalt properties may change when stored at high temperatures for long periods of time. Asphalt may become harder or may experience what is known as “fallback”. Fallback is the degradation of the asphalt to the point that its physical properties (i.e. softening point) deteriorate which could then cause roof slippage. To reduce the chances of fallback, the following recommendations should be implemented:
    • Use higher softening point asphalt.
    • Decrease the kettle temperature as much as possible, while maintaining the minimum application temperature.
    • Use material as quickly as possible, thus reducing exposure time.
    • Insulate all lines and equipment used to transport asphalt.


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