Division 7 - Thermal and Moisture Protection
     Section 07550 Protective Membrane Roofing, 3.04 Flashing

image 5: Flashing.

The images show typical roof penetration with counter flashing accomplished with movable connections facilitating thermal expansion and building movement.

Image 5 is of a special laboratory vent pipe, which will expand and contract at a different rate than the roof composite slab. Counter flashing is secured by the use of stainless steel clamps.

image 6: Exhaust stack and curb.

image 7: Stainless steel exhaust with counter flashing collar.

Images 6 & 7 are of a stainless steel roof stack which is exhausting fume hoods from laboratories below. The movement of dissimilar materials, densities, and/or temperature differentials must be taken into account at this critical assembly juncture in order to maintain the integrity of the roof membrane against water penetration. The roof assembly of a building has historically been the cause of 90% of all litigation for building failures while costing only 10% of the construction budget.

Division 7
Page 4 

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