2CNN-W/2PNN-W. CSI 3-Part Specifications.

General

This specification is for use over any type of approved structural deck (without insulation) which can receive and adequately retain nails or other mechanical fasteners that may be recommended by the deck manufacturer. Examples of these decks are wood, plywood, and approved oriented strand board (OSB). This specification is not for use over light-weight insulating concrete decks.

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, start with a piece 19 3/4" (502 mm) wide. The remaining plies are to be applied full width 3" (76 mm) side and 4" (102 mm) end laps over the preceding sheets. Nail 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 nails or fasteners appropriate to the type of deck, with 1" (25 mm) minimum diameter caps. For additional fastener information, refer to the fastener data in the "Roof Decks" section of the current JM Commercial/Industrial Roofing Systems Manual.

Heat weld a full width piece of one of the cap sheets listed so that it is firmly and uniformly set. Subsequent sheets are to be applied in the same manner, with 4" (102 mm) side and 6" (152 mm) end laps over the preceding sheets. All laps must be rolled with a 3" (76 mm) rounded edge roller.  A 1/8" to 3/8" (3 mm to 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 recommended 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

No additional surfacing is required.

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

For an identical copy of this specification, ask for RS-4355.