Flashings, Transitions, & Terminations
Flashings, transitions, and terminations shall be installed as shown in the "Roof Flashing Details" index. Non-asphalt surfaces such as concrete and metal that come in contact with asphalt BUR components shall first be primed with M400 RubrPrime at the uniform rate of one gallon per 100 square feet, and the primer shall be allowed to dry prior to further installations.

M60 RubrPoly Flashing Membranes
Flashing membranes shall be constructed from M60 RubrPoly sheets. Cut the RubrPoly sheets to size and install in a manner that minimizes the occurrence of voids and wrinkles, taking care that the RubrPoly flashing sheets do not bridge where there is a change of direction such as where a wall intersects with the plane of the roof deck. Ensure that the drainage flow is over or parallel to the flashing membrane seams in a manner similar to the roof membrane seams. Apply pressure to the flashing seams so as to make complete adhesion. Flashing sheet seams shall be carefully inspected, and unsealed locations, voids, or raised membrane intersections shall be repaired.

Metal Counterflashings & Cap Flashings
Sheet metal counterflashings shall be installed to cover the top of curbs and to overlap the upper sheet edges of flashing membranes. On curbs that support equipment being frequently serviced, the counterflashings shall extend down over the flashing membrane to the base of the cant, terminating near the roof surface so that the flashing membranes are well protected.

On certain prefabricated roof hatches, skylight systems, and rooftop equipment, a relatively short, built in metal counterflashing flange may be provided making it necessary to attach an additional sheet metal counterflashing skirt. The sheet metal skirt shall be installed to extend the premanufactured counterflashing so as to ensure adequate overlap of the flashing membranes, thus restricting wind driven rain and snow from penetrating the roof system. Since metals generally have a high coefficient of expansion, metal flashings shall be isolated from the BUR membrane so as to minimize metal movement from fatiguing or splitting the BUR membrane. Metal flanges are prohibited from being embedded or sandwiched into the reinforcing membrane.

Walls that require flashing membranes shall have metal counterflashings installed in or on the wall above the flashings. The design of this counterflashing shall consist of a separate reglet and counterflashing allowing installation of the sheet metal counterflashing after the flashing membrane is installed. Refer to the "Roof Flashing Details" index. Single piece counterflashings are prohibited. Sheet metal is prohibited from being installed as a flashing embedded into asphalt or the BUR membrane where differential movement may result in fatiguing, cracking, or splitting the roof system membrane.

When precast concrete walls are installed, the designer shall specify the flashing requirements for interfacing the BUR membrane with the precast wall units. Cast-in raggles, often mistakenly called reglets, are prohibited. Design attention shall be given to camber, creep, and the independent thermal movement of the precast concrete walls, the BUR membrane, and the flashing system.

For non-wall supported roof decks, the flashing membranes shall be fastened to a vertical wood upright with the horizontal base attached to the roof deck. Refer to the "Roof Flashing Details" index for examples of vertical wood blocking. After the flashing membranes have been attached to the wood uprights, the metal counterflashings shall be extended down over the flashing membranes. This detail allows for independent movement of the wall and metal counterflashings without damage to the roofing membrane and flashing membrane.

Metal cap flashings or copings are often installed to cover the top of a wall in lieu of masonry copings. Refer to the "Roof Flashing Details" index. For intermediate height parapet walls, metal counterflashings shall be attached to the inside face of metal cap flashings.

Metal gravel stops shall be raised above the waterline or surface of the roof by installing tapered wood blocking. The flange of a metal gravel stop shall be placed over the completed BUR membrane and shall be fastened a minimum of 3" on center to the perimeter of the wood nailer. The gravel stop metal flanges shall be adhered within the flashing membrane sheets. Refer to the "Flashing Details".

Pipe projections through the roof system require metal flashing collars or pipe flashing boots. Metal flashing flanges shall be installed with M60 RubrPoly. Refer to the "Flashing Details".

Metal Materials
To help ensure weather secure joints with various metal roofing and flashing metals, clean the metal with a solvent dampened rag to remove dirt, dust, and oils so as to prepare the surfaces to be securely mated.

Overlapped metal joints are required to be sealed from water intrusion with M60 RubrPoly and M300 RubrMastic installed in a three-layer application.

Metal installed as flashings shall be mechanically fastened, and adhered in M300 RubrMastic. In addition, some types of metal seams may be joined with solder or by welding.

Roof System Membrane Protection

Foot traffic can be detrimental to a roof system, especially during extreme temperatures, and therefore must be controlled. Traffic pads or walkways shall be installed in areas that will receive regular maintenance traffic. Pads and walkways shall not be mechanically fastened to or through the roof membrane. All sharp edges shall be eliminated from metal walkways. Asphalt composition walkways are prohibited. Walk pads shall be spaced no closer than 6" from adjacent pads. Walk pads shall not block water run off drainage.

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