of application. When the flashing material is ready for application, press into place so that the material is firmly and uniformly set.

8.6.6 For heat weld application, all safety procedures must be reviewed prior to application. All contractors must understand, review and adhere to the information contained in the following sources:

Johns Manville Safety Guidelines for Heat Weld Application

ARMA Guide to Torch Safety

ARMA Torch Safety Video

 

8.7 Cold Adhesive Application of SBS Modified Bitumen Flashings

8.7.1 Cold adhesive flashing systems are very similar in construction to hot-applied systems. JM has developed two adhesives, MBR Flashing Cement and MBR Utility Cement, that are compatible with both BUR and modified bitumens. When cured, these adhesives form a durable, elastomeric and watertight film. Unlike conventional cut-back mastics, and most other "modified bitumen cold-process adhesives", MBR Flashing Cement and MBR Utility Cement will not damage the SBS blend in the modified bitumen sheet.

8.7.2 MBR Flashing Cement and MBR Utility Cement can be used as a substitute for asphalt in modified bitumen flashing specifications. They can also be used as a general purpose mastic on most built-up roofing and modified bitumen flashing details, or to strip-in the laps of modified bitumen base flashing.

8.7.3 The major benefit derived from the use of these adhesives is that they provide the mechanic with an alternative means of terminating the roof membrane when hot asphalt is not desired, not practical, or is prohibited. In addition, these adhesives offer exceptionally good weathering properties and can be used as a utility mastic in other applications such as counterflashing.

8.7.4 MBR Flashing Cement is a two component, modified bitumen adhesive. It must be prepared on site by mixing the MBR Flashing Cement Base and MBR Cement Activator. The mixing and application instructions must be strictly followed in order for the material to work as intended.

8.7.5 MBR Utility Cement is a one component, trowel grade, modified bitumen adhesive designed for use with SBS modified bitumen flashing products. Its formulation contains very low levels of a mild petroleum solvent, which make it compatible with all of the JM SBS modified bitumen and built-up roofing products. It is available in both a "winter" and "summer" grade. Both formulas contain the same basic ingredients, but the consistency is adjusted to accommodate the weather conditions during application.

8.7.6 SBS modified bitumen sheets are heavy. To prevent slippage when installed on a vertical surface, the sheets must be secured with nails or mechanical fasteners. If the surface to which the flashing material will be attached cannot accommodate nails or other fasteners, MBR Flashing Cement must be used in lieu of MBR Utility Cement, since it "sets up" more quickly, and will not slip once cured.

Note: Do not use conventional cut-back asphalt cements to bond any JM modified bitumen roofing product to any substrate.

8.7.7 Although JM does not recommend the use of conventional solvent-based roofing mastics or flashing cements for bonding modified bitumen materials, they can be used to strip in laps and other terminations using the same techniques used for built-up roofing. Typically, a 4" - 6" (102 mm - 152mm) wide bed of mastic is laid down over the lap, a strip of glass fabric or ply felt is embedded into it, then coated with a layer of roof mastic.

8.8 Two-Part Cold Adhesive Equipment

8.8.1 The following equipment is necessary for the safe and efficient preparation and application of JM MBR Flashing Cement.

8.8.2 Safety and Personal Hygiene Equipment: The following items should be available for, and used by, every worker:

A. Impervious gloves, 1 pair for each worker.

B. Rubber or plastic apron, 1 for every person mixing.

C. Organic cartridge respirator mask. Air-supplied respirators may be required for some applications.

D. Chemical safety goggles, 1 for each person mixing or spraying.

E. Soap and water.

F. Hand cleaner.

G. Supply of clean rags.

H. Solvent: paint thinner, or mineral spirits.

I. Portable fire extinguisher.

J. Squeeze bottle filled with clean water for use as an eye wash.

8.8.3 The following items may be required at the job site to protect the installation and surrounding areas during application.

A. Heavy wrapping paper or suitable protective sheeting.

B. 2" (51 mm) wide masking tape.

8.8.4 Mixing Equipment:

A. Jiffy Mixer Model PS, or equivalent.

B. ½" (13 mm) electric drill motor and power source.

C. Plastic graduated container for measuring activator and base material.

8.8.5 Application Equipment:

A. Clean 5 gallon (18.9 liter) metal pails.

B. Solvent: paint thinner or mineral spirits.

C. All tools normally used in the application of built-up roofing materials.

8.8.6 Adhesive Preparation: MBR Flashing Cement is prepared on site by adding specific amounts of MBR Cement Activator to MBR Flashing Cement Base and mixing thoroughly. The adhesive is prepared in the MBR Flashing Cement Base shipping container, a 5½ gallon (20.8 liter) pail, using a Jiffy Mixer mounted on a ½ " (13 mm) drill motor. The container of MBR Cement Activator is packaged to provide exactly the correct amount of material necessary to react with the contents of the MBR Flashing Cement Base pail (4 gallons [15.1 liters]). The Activator is heavier and has a lower viscosity than the base material. To ensure a complete mix, the MBR Cement Activator must be poured slowly into the vortex caused by the rotating mixer. THE ACTIVATOR MUST NOT BE DUMPED INTO THE PAIL IN ONE MOTION. The mixer should be constantly moved about the pail in an up-and-down and side-to-side motion. The mixing is complete in about 3 minutes. Do not overmix!