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APP Modified Bitumen Specifications |
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2. Mop one ply of an approved JM ply felt in ASTM D 312, Type III asphalt and apply a glaze coat of 10 - 15 lbs. per square (0.49 -
0.73 kg/m2) of Type III asphalt.
3. An alternate would be to heat weld one layer of an APP or PAO modified bitumen cap sheet (smooth or mineral surfaced) over
the base felt. No glaze coat of asphalt is applied.
4. When the permanent roof is to be installed, inspect the roof and remove all damaged and blistered areas. Apply a layer of
approved JM base felt nailed through the temporary roof and into the deck as the first layer of the roofing system. As an alternate,
a layer of approved JM roof insulation may be mechanically fastened (with appropriate fasteners) through the temporary roof into
the deck.
5. Proceed with installing the appropriate permanent roof specification.
B. Steel Decks:
1. Apply a minimum layer of Fesco Board of adequate thickness to the steel deck using appropriate length UltraFast fasteners.
2. Install a ply of a JM ply or base felt and an additional ply of fiber glass felt, both in hot steep asphalt.
3. Finish with a 10 - 15 lbs. per square (0.49 - 0.73 kg/m2) glaze coat of hot steep asphalt.
4. When the permanent roof is to be applied, inspect the roof area. If the insulation has not been damaged and is dry, remove any
blistered or damaged felt. Prime the temporary roof with JM Concrete Primer at the rate of 1 gal./sq. (0.4 liters/m2) and then solid
mop a layer of insulation board to the temporary roof with hot asphalt. Then apply the permanent roof system.
5. If the membrane and/or roof insulation has been excessively damaged, remove all unusable material and replace.
C. Non-Nailable Decks, other than Steel:
1. Prepare the deck as would be done for a permanent roof.
2. Solid mop two plies of approved JM ply felt in hot Type III asphalt.
3. Finish with a 10 - 15 lbs. per square (0.49 - 0.73 kg/m2) glaze coat of Type III asphalt.
4. When the permanent roof is to be installed, inspect and repair all defects in the temporary roof. Clean the surface of the
temporary roof and prime with JM Concrete Primer if the surface is unusually worn. Proceed with the installation of the permanent
roof.
5. As an alternate to step 2, spot mop an approved JM base sheet using a mechanical spot mopping machine. Next, solid mop
one ply of approved JM ply felt in hot Type III asphalt. When the permanent roof is to be installed, remove the entire temporary roof,
prime the deck as required in the "Roof Decks" Section of this manual, and proceed with the installation of the permanent roof.
7B.15.3 The decision as to whether or not a temporary roof is to be left in place is a judgment factor that must be made by the building owner
or his representative. Although a JM representative may make suggestions in this area, JM will not be responsible for any problems that may
develop with the roofing system due to the fact that the temporary roof is left in place.
7B.16 Protected Roofing Membrane Assemblies (PRMA)
7B.16.1 General Information. All general information contained in this section and the current JM Commercial/Industrial Roofing Systems
Manual shall be considered part of these specifications.
JM APP and PAO modified bitumen specifications are eligible for use with protected roofing membrane assemblies. When these
specifications are modified, the last digit of the specification designation should be changed to a "P" to denote "Protected" (e.g., 3CIP-W).
Flashings: All flashings must conform to the requirements stated in this section and the current JM Commercial/Industrial Roofing Systems
Manual. The flashing material must extend above the top of the extruded polystyrene insulation a minimum of 8" (203 mm). The standard
flashing details for modified bitumen roofing can be found in "Bituminous Flashings", Section 8.
Drainage: Design and installation of the deck and/or roof substrate must result in the roof draining freely, to outlets numerous
enough and so located as to remove water promptly and completely. Areas where water ponds for more than 24 hours are
unacceptable, and will not be eligible for a JM Roofing System Guarantee.
7B.16.2 When designing a protected membrane roofing system, the designer must make sure that positive drainage exists on the roof. Even
though some extruded polystyrene roof insulation products are designed with integral drainage channels, they will retard the flow of water due
to the contact between the membrane and the insulation. JM recommends a minimum of 1/4 " per foot (20.8 mm/m) slope be obtained on the
finished roof membrane. This will greatly reduce the amount of water that will be retained against the membrane after a rain.
7B.16.3 Ballast Requirements (for use with extruded polystyrene roof insulation):
7B.16.4 The ballast should be similar to ASTM D 448, Gradation #57. The following gradation is typical:
Passing 1/2 " (13 mm) 10-60%
Passing 3/4 " (19 mm) 100%
7B.16.5 Ballast is applied at a rate of approximately 10 to 12 lbs. per square foot (48.8 - 58.6 kg/m2) in the field of the roof over a layer of filter
fabric. Twenty (20) lbs. per square foot (97.6 kg/m2) of ballast is required over a 4' (1.22 m) wide area at the roof perimeter and at all
penetrations. The following fabrics have been found to be acceptable:
A. Confil 689H – 3.0 oz./yd. (93.5 g/m) black polyester from International Paper Company.
B. Rufon P3B – 3.0 oz./yd. (93.5 g/m) black polypropylene from Phillips Fiber Corporation.
