SBS Expansion Joint (Field)

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SBS Expansion Joint (Field)

Division D - Construction Details

SBS | Expansion Joint (Field) ( Article

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SBS Details


(1) Air or Vapour Control Layers
If required by design authority
(2) Insulation
See available insulation products in the Accepted Materials section of this Manual.
(3) Insulation Overlay
As required.
(4) Primary Membrane and Membrane Protection.
(5) Membrane Flashing
Mechanically fasten to top of blocking (C).
(6) Membrane Underlay
Minimum self-adhered modified bitumen or as per membrane manufacturer’s recommended detail.
(7) Metal Counter-flashing
Mechanically fasten to top of wood blocking. Optional on flexible membrane systems. Required on assemblies using gravel ballast filter mats. Also called a base flashing.
(8) Metal Cap Flashing
Top surface must be sloping. Extend beyond and over-break at top corners. Fasten with concealed clip-type fasteners or cladding screws evenly spaced between seams.


(A) Acceptable Supporting Deck Structure
(B) Air / Vapour Seal
(C) Expansion Joint Assembly
Minimum 200 mm (8") and maximum 300 mm (12") above finished roof surface. Minimum height may be reduced to 100mm (4") if the primary roof membrane flashing is fully supported and sealed over the top. Primed where applicable. Top must be sloped.
(D) Flexible Insulation

NOTE: See the Standard for additional requirements.

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