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BUR Section 5: Insulation

BUR-5.1 General

  1. Primary insulation is the system component that provides the major portion of the thermal performance of the roofing system. The location of the primary insulation can vary depending on the roofing system design type.
  2. For ARCA Warranty Ltd. acceptance, insulation products must be tested by a certified testing agency, approved by the Standards Council of Canada, such as the Underwriters’ Laboratories of Canada (ULC) or a Canadian Construction Materials Centre (CCMC) evaluation listing to verify compliance to an existing insulation standard. Third party certified thermal insulation products are accepted by specific manufacturer and product name, and are not accepted generically for inclusion under the Warranty Certificate Program.
    *REVISED 2012-03
  3. To eliminate confusion during the tendering process, it is recommended that the design authority specify roof insulation by the type and thickness of insulation to be used. Specifying insulation by thermal resistance values may lead to confusion during the construction process as insulation thickness affects the design heights of other building components, such as perimeters, curbs and sleepers.
  4. Roof insulation shall be protected during shipping and site storage to prevent moisture infiltration and damage. No insulation material, either primary or secondary, is to be installed when its moisture content exceeds the manufacturer’s stated equilibrium moisture content. Surface moisture should be allowed to dry. Wet or damp insulation that cannot be dried must be removed and replaced with dry insulation.
  5. When specifying plastic foam insulation, the design authority must ensure compliance with Alberta Building Standards relative to the use of thermal barriers, as this falls outside the expertise of the roofing contractor.
  6. Only new insulation shall be installed in new conventional insulated roofing assemblies.
    *ADDED 2017-11

BUR-5.2 Insulation Blocking For Sloped Decks

  1. To prevent primary membrane movement or displacement, continuous wood nailers or blocking shall be mechanically fastened to the decking when deck slopes exceed 1:8 (1.5”/ ft.) when using organic felt or 1:12 (1”/ ft.) when using inorganic felt. The design of the insulation blocking system is the responsibility of the design authority and is not covered by the Warranty Certificate.
  2. When insulation blocking is required, all roofing system components shall be uniformly adhered to each other and to their supporting substrate. Multiple layers of primary insulation require multiple layers of insulation blocking. The upper nailers shall be oriented perpendicular to the direction of the primary membrane.
  3. The size and spacing of the blocking shall match the primary insulation board dimensions and shall provide for the back nailing of the primary membrane. The maximum spacing permitted between the blocking is 1200mm (4 ft.). The top surface of the primary insulation shall be flush with the top of the blocking.
    *REVISED 2010-06
  4. The secondary insulation shall be adhered to the primary insulation and shall be mechanically fastened to the blocking.

BUR-5.3 Primary Insulation

  1. The primary insulation shall be uniformly adhered to the vapour retarder in a full application of hot bitumen, with an approved adhesive or mechanically fastened through the vapour retarder to the structural deck.
  2. Insulation boards shall be tightly butted together and installed in a staggered pattern. Sloped or tapered insulation may be installed in a soldier or staggered pattern. Gaps at board joints greater than 6.4mm (1/4″) in width shall be filled with insulation.
    *REVISED 2020-12
  3. When multi-layers of primary insulation are specified offset board joints by a minimum distance of 150mm (6″) from the preceding insulation layer.
  4. When insulation is adhered with adhesive or hot bitumen, restrict board size to no greater than 1200mm x 1200mm (4 ft. x 4 ft.) dimensions for proper adhesion.

BUR-5.4 Secondary Insulation

  1. The primary insulation shall be covered with a minimum 12.7mm (1/2″) thick layer of coated fiberboard or perlite roof insulation. The secondary insulation provides a preferred substrate for the adhesion of the primary membrane as well as provides some additional thermal resistance.
    *REVISED 2012-03
  2. Secondary insulation shall be uniformly adhered to the primary insulation in a full mopping of hot bitumen, an adhesive approved by the primary membrane manufacturer or mechanically fastened to the structural deck.
  3. Secondary insulation (coverboard) shall be installed in a staggered pattern with joints supported and staggered a minimum distance of 150mm (6″) from the joints of the underlying insulation.
    *REVISED 2020-10
  4. For proper adhesion when using hot bitumen, the secondary insulation boards shall not exceed 1200mmx2400mm (4 ft. x 8 ft.) in size.
  5. Secondary insulation boards exceeding 1200mmx2400mm (4 ft. x 8 ft.) in size shall be mechanically fastened to the decking.
  6. For hot applied membranes, the top surface of standard fiberboard or stone wool secondary insulation shall be manufactured with an asphalt coating. Wax or asphalt impregnated fiberboard need not be asphalt coated.
    *REVISED 2012-03
  7. When polystyrene insulation forms the primary insulation layer, the secondary insulation shall be comprised of a single layer of 25mm (1”) thick shiplap edged or two (2) 12.7mm (1/2”) thick layers of butt edged impregnated/coated fiberboard or perlite roof insulation. Each secondary insulation layer shall be adhered with hot bitumen using the “mop and flop” back coating application method.

BUR-5.5 Asphalt Core Boards

  1. Asphalt core board may be substituted for the secondary insulation layer over selected primary roof insulation when its application is approved by the primary membrane manufacturer.
    *ADDED 2013-10
  2. Polystyrene insulation forms the primary insulation layer, the asphalt core board shall be comprised of two (2) 3.2mm (1/8”) thick layers of butt edged asphalt core boards. Each cover board layer shall be adhered with hot bitumen using the “mop and flop” back coating application method. Offset board joints of the board a minimum of 150mm (6”) from the underlying layer.
  3. One layer of minimum 3.2mm (1/8”) thick asphalt core board is acceptable over faced insulations that are not heat sensitive for direct mopping application.

BUR-5.6 Accepted Roofing Insulation

BUR-5.6.1 Primary Insulation

  1. Each listed insulation manufacturer has confirmed third party product certification by an accredited independent testing agency, in accordance with ARCA Warranty Ltd. insulation acceptance criteria.
  2. The design authority shall obtain long term thermal resistance (LTTR) values from the insulation manufacturer and shall specify primary insulation by thickness

Polyisocyanurate Roof Insulation

Atlas Roofing Corporation

  • AC Foam-11


  • ISOGARD GL Polyisocyanurate
  • ISOGARD CG Polyisocyanurate

Hunter Panels LLC (Carlisle)

  • H-Shield Polyisocyanurate
  • Carlisle Polyisocyanurate

IKO Industries Ltd.



  • Polytherm
  • Polytherm G


  • Paratherm
  • Paratherm CG


  • Sopra-ISO (e)
  • Sopra-ISO (s)
  • Sopra-ISO (r)
  • Sopra-ISO
  • Sopra-ISO Plus


  • Trisotech

Expanded Polystyrene Roof Insulation


  • Envirosheet Type 1
  • Envirosheet Type 2
  • Envirosheet Type 3

Beaver Plastics Ltd.

  • Terrafoam Type 1
  • Terrafoam Type 2

Plasti-Fab Ltd.

  • Plasti-Span Type 1
  • Plasti-Span Type 2
  • Plasti-Span Type 3

Great White Foam

  • Type 1
  • Type 2


  • EPS+ Type 1
  • EPS+ Type 2
  • EPS+ Type 3

Extruded Polystyrene Insulation

Owens Corning Canada

  • Foamular C-300 & 350


  • DeckMate Type 2
  • DeckMate 200 Type 3
  • RoofMate Type 4
  • Deckmate PLUS FA


  • SOPRA-XPS 35
  • SOPRA-XPS 40
  • SOPRA-XPS 60
  • SOPRA-XPS 100 

Mineral Fiber Roof Insulation


  • Soprarock DD (Plus)

Fiberboard Roof Insulation

Building Products Of Canada (BP)

  • ESGARD High Density (HD) Roof Insulator
  • ESGARD High Strength (HS) Roof Insulator

MSL Louiseville Fibreboard Inc.

  • Wood Fibreboard Insulation


  • Soprafibre 1C

BUR-5.6.2 Secondary Insulation

  1. Acceptances of secondary insulation products by ARCA Warranty Ltd. is on an individual product basis. The insulation acceptance criteria provide for specific manufacturing or application parameters pertaining to each listed product.

Building Products of Canada (BP)

  • ESGARD High Density (HD) Roof Insulator
  • ESGARD High Strength (HS) Roof Insulator

MSL Louiseville Fibreboard

  • Wood Fibreboard Insulation


  • Soprafibre 1C

BUR-5.6.3 Asphalt Core Boards

IKO Industries Ltd.

  • min 3.0mm thick PROTECTOBOARD


  • min 3.2mm thick SOPRABOARD

HAL Industries Inc.

  • min 4.5mm thick PERMA-BOARD

BUR-5.7 Polyurethane Foam Adhesive For Insulation And Asphalt Core Board

BUR-5.7.1 General

  1. A primary membrane manufacturer’s accepted low-rise two component, chemical cure, polyurethane foam adhesive, when used in compliance with the manufacturer’s written application instructions, may be used to uniformly adhere accepted insulation and asphalt core boards to one another, to accepted vapour retarders, insulation and substrates.
  2. The primary membrane manufacturer’s insulation adhesive(s) have been evaluated by ARCA Warranty Ltd. for specific applications and are not accepted as general purpose roofing adhesives and are not to be substituted for other accepted primary membrane manufacturers insulation adhesives.
  3. Prior to dispensing foam, store adhesive at recommended application temperature and ensure adhesive shelf life date has not been exceeded.
  4. Foam insulation adhesives may be dispensed to clean moisture free substrates by wand or spray equipment applied in accordance with adhesive manufacturer’s application rates. For wand applications, maintain proper adhesive ribbon size and spacing for roof field, perimeter and corners. When spraying, maintain minimum coverage rates.
  5. Protect newly applied foam adhesive from contamination prior to bonding roofing components. Follow adhesive manufacturer’s post application requirements for weighting, rolling or walk-in insulation boards into the uncured adhesive to prevent air gaps from forming between insulation boards and their supporting substrate.
  6. When polyisocyanurate roof insulation forms the primary insulation layer, insulation boards shall not exceed 1200mmx1200mm (4 ft. x 4 ft.) in size.
    *ADDED 2015-01

BUR-5.7.2 Accepted Roof Insulation Adhesives

  1. The adhesives listed below by membrane manufacturer have been evaluated and accepted for specific applications. Accepted adhesives are not general purpose roofing adhesives and are not interchangeable amongst membrane manufacturers.

Polyurethane Foam Insulation Adhesive

Two component low-rise, chemically cured urethane foam adhesive for the attachment of selected rigid roof insulation and cover boards to one another and to fully adhered vapour barriers.

Carlisle (Approved Carlisle Systems Only)

  • FAST ADHESIVE Dual Cartridge

Elevate (Approved Elevate Systems Only)

  • I.S.O. TWIN PACK Insulation Adhesive

IKO Industries Ltd. (Accepted IKO Systems Only)

  • Millennium Adhesive Products, Weather-Tite One Step Foamable Adhesive

Soprema (Approved Soprema Systems Only)

  • DUOTACK Roof Insulation and Coverboard Adhesive
  • DUOTACK 365 Roof Insulation and Coverboard Adhesive

Other Insulation Adhesives

When approved for application by the membrane manufacturer and accepted by ARCA Warranty Ltd. on a project by project basis.

Siplast Canada Inc. (Approved Siplast Systems Only)

  • PARASTIK Adhesive