The proper application of roofing materials is as important as the materials themselves. The following are recommended guidelines for the application of all roofing materials. (See also Fig. 5-3.)
■ Never use wet or damaged materials.
■ Never apply any roofing materials during rain or snow, or to wet surfaces. Moisture trapped within the roofing system can cause severe damage to the roofing membrane and insulation.
■ Review the application guidelines in this book.
■ Never mop more than 4 feet ahead of the roll in temperatures below 50°F.
9 4
CHAPTER FIVEF I G U R E 5 - 3 Applying BUR materials.
✓ Item
Never use wet or damaged materials.
Never apply any roofing materials during rain or snow, or to wet surfaces. Moisture trapped within the roofing system can cause severe damage to the roofing membrane and insulation.
Review the application guidelines in this book.
Never mop more than 4 feet ahead of the roll in tempera-tures below 50°F.
Observe EVT guidelines for asphalt application.
When using mechanical felt-laying equipment, be sure all orifices are open.
Lightly squeegee all fibrous felts into the hot asphalt.
Roll all felts into the hot asphalt. Do not “fly” felts into the asphalt.
Take special care when applying any roofing felts in cold weather. Check the temperature of the asphalt at the mop or spreader to determine if it is at the proper tempera-ture.
Do not mix different grades of asphalt or dilute asphalt with any materials.
Do not use coal-tar pitch or bitumen with any MBR products.
Do not use cutback asphalt cements under any MBR pro-ducts. The use of the mastics over the top of the product to strip in or cover nailheads is acceptable; however, MBR cement products are preferred.
Heat the asphalt according to the manufacturer’s recom-mendations. Check the temperature of the asphalt at the kettle and at the point of application.
Adhere to the guidelines for heating asphalt in this book.
F I G U R E 5 - 3 (Continued)
✓ Item
Use the proper grade asphalt as specified by the mem-brane manufacturer. A good guideline to follow is to use the softest grade of asphalt commensurate with the slope and climate conditions.
Install water cutoffs at the end of each day’s work to pre-vent moisture from getting into and under the completed roof membrane. Be sure to remove the cutoffs prior to continuing the application process.
Heed the specific cold-weather application procedures given in this chapter.
Install the complete roofing system at one time. Phased construction can result in the felts slipping because of excessive amounts of asphalt between the phased felt plies. Blisters, due to entrapment of moisture, are also a common problem, as is poor adhesion due to dust or foreign materials collecting on the exposed felts of an incomplete roofing system.
During the asphalt setting time, which can be as long as 45 minutes, it is essential that traffic be minimized so that the interply mopping is not displaced.
Comply with published safety procedures for all pro-ducts. Refer to appropriate instructions and product safety information.
■ Observe EVT guidelines for asphalt application.
■ When using mechanical felt-laying equipment, be sure all ori-fices are open.
■ Lightly squeegee all fibrous felts into the hot asphalt.
■ Roll all felts into the hot asphalt. Do not “fly” felts into the asphalt.
■ Take special care when applying any roofing felts in cold weather. Check the temperature of the asphalt at the mop or spreader to determine if it is at the proper temperature.
■ Do not mix different grades of asphalt or dilute asphalt with any materials.
■ Do not use coal-tar pitch or bitumen with any MBR products.
■ Do not use cutback asphalt cements under any MBR products.
The use of the mastics over the top of the product to strip in or cover nailheads is acceptable; however, MBR cement products are preferred.
■ Heat the asphalt according to the manufacturer’s recommenda-tions. Check the temperature of the asphalt at the kettle and at the point of application.
■ Adhere to the guidelines for heating asphalt in this book.
■ Use the proper grade asphalt as specified by the membrane man-ufacturer. A good guideline to follow is to use the softest grade of asphalt commensurate with the slope and climate conditions.
■ Install water cutoffs at the end of each day’s work to prevent moisture from getting into and under the completed roof mem-brane. Be sure to remove the cutoffs prior to continuing the application process.
■ Heed the specific cold-weather application procedures given in this chapter.
■ Install the complete roofing system at one time. Phased con-struction can result in the felts slipping because of excessive amounts of asphalt between the phased felt plies. Blisters, due to entrapment of moisture, are also a common problem, as is
9 6
CHAPTER FIVEpoor adhesion due to dust or foreign materials collecting on the exposed felts of an incomplete roofing system.
■ During the asphalt setting time, which can be as long as 45 min-utes, it is essential that traffic be minimized so that the interply mopping is not displaced.
■ Comply with published safety procedures for all products. Refer to appropriate instructions and product safety information.