3CBN-W/3PBN-W. CSI 3-Part Specifications.

	APP Modified Bitumen Specifications
	Specification 3CBN-W/3PBN-W

General

This specification is for use over any type of approved structural deck with insulation or approved substrate which is suitable to receive a mechanical fastener and which provides an acceptable surface to receive the roof.

Specific written approval is required for any roof insulation that is not  supplied by JM. Insulation shall be installed in accordance with the appropriate JM Insulation Specification detailed in the JM Commercial/Industrial Roofing Systems Manual. This specification can also be used in certain reroofing situations. Refer to the "Reroofing" section of the JM Commercial/Industrial Roofing Systems Manual. This specification is not to be used over gypsum, either poured or pre-cast, or lightweight insulating concrete decks or fills.

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.

Note: This specification is also for use with JM PAO (Classic) products. All general instructions contained in the current JM Commercial/Industrial Roofing Systems Manual shall be considered part of this specification.

Flashings

Flashing details can be found in the "Bituminous Flashings" section of the JM Commercial/Industrial Roofing Systems Manual.

Application

Using one of the base plies listed, mechanically fasten with an approved JM insulation fastener and plate, a 26 1/4" (665 mm) wide piece of base ply through the insulation. The remaining base plies are to be applied full width with 3" (76 mm) side and 4" (102 mm) end laps over the preceding sheets. Fasten the laps at 9" (229 mm) centers, and down the longitudinal center of each felt ply, place two rows of fasteners, with the rows spaced approximately 11" (279 mm) apart, and fasteners staggered on approximately 18" (457 mm) centers. Use fasteners appropriate to the insulation and deck. For additional fastener information, refer to the fastener data in the "Roof Decks" section of the current JM Commerical/Industrial Roofing Systems Manual.

Over the fastened base ply, heat weld a 19 3/4" (500 mm) piece of one of the intermediate plies listed with a 4" (102 mm) side and 6" (152 mm) end laps. The remaining plies are to be applied full width, in the same manner, with 4" (102 mm) side and 6" (152 mm) end laps over the preceding sheet.

Over the existing two plies, heat weld a full width piece of one of the cap sheets listed. Subsequent sheets are to be applied in the same manner, with a 4" (102 mm) side and 6" (152 mm) end laps over the preceding sheets.

Heat weld all plies so that they are firmly and uniformly set. All laps must be rolled with a 3" (76 mm) rounded edge roller. A 1/8" to 3/8" (3 mm - 10 mm) bleedout of APP compound shall be visible at the edge of all seams. All laps must be checked for good adhesion.

Preparation of the 6" (152 mm) end lap requires scuffing away all loose granules. Heat and embed all remaining granules. Apply heat to the roll being seamed while making sure both have a good compound flow to adhere the two surfaces. End laps must be checked for proper adhesion.

Application of JM APP/PAO Modified Bitumen Products may require the use of an open flame propane torch. Improper use of these materials and application equipment can result in severe burns, and/or other physical injury, as well as damage to property. In order to prevent these situations the mechanic must install the materials using the techniques rec-ommended by JM and those found in "A Guide to Safety: Torch-On  Modified Bitumens" available from the Asphalt Roofing Manufacturers Association. These techniques have been endorsed by the National Roofing Contractors Association and the United Union of Roofers, Waterproofers and Allied Workers.

For special precautions for heat weld application of JM Classic (PAO) products, refer to Paragraph 7B.6.6.

For cold weather application techniques, refer to Paragraph 7B.14.

Steep Slope Requirements

Special procedures are required on inclines over 2 1/2" per foot (208 mm/m). Refer to Paragraph 7B.12.

Surfacing

Note: When using metric and English sized sheets in the same system, care should be taken to avoid lap over lap configurations.

For an identical copy of this specification, ask for RS-4346.