2CIS-W/2PIS-W (Alternate). CSI 3-Part Specifications.

General

This specification is for use over any type of approved structural deck which is not nailable and which provides a suitable surface to receive the roof. Poured and pre-cast concrete decks require priming with JM Concrete Primer prior to application of the first heat welded modified bitumen ply. This specification is not to be used over poured or pre-cast gypsum decks, lightweight insulating concrete decks or fills without JM insulation.

This specification is also for use over JM roof insulations, or other approved roof insulations which are not nailable and which provide a suitable 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 Commerical/Industrial Roofing Systems Manual. JM Nord Board is unacceptable as the top layer of insulation.

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

Roll an 18" (457 mm) wide piece of one of the base plies listed into a full mopping of bitumen. Over that, apply a full width piece. The remaining plies are to be applied full width with 3" (76 mm) side and 4" (102 mm) end laps over the preceding sheets. Do not glaze coat felts.

Apply all felts so that they are firmly and uniformly set, without voids, into the hot bitumen. Bitumen temperature should be the Equiviscous

Temperature (EVT), ±25°F (±14°C), at the point of application. All felt edges shall be well sealed. The bitumen shall be applied just before the felt, at a nominal rate of 23 lbs. per square (1.1 kg/m²). When applying over insulations, more than 23 lbs. per square (1.1 kg/m²) of bitumen may be needed due to the absorbency of the insulation.

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.

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 1/2" per foot (41.6 mm/m). Refer to Paragraph 7B.12.

Surfacing

Smooth surfaced membranes must be coated with a JM approved coating. The coating chosen will depend on aesthetics and any fire rating or Code approval required.

Asphalt

Asphalt should meet the requirements of ASTM D 312.

JM Guarantees require the use of Trumbull asphalt or another JM Approved Asphalt. The Contractor must provide an Asphalt Confirmation Number (ACN) on projects which require a JM Guarantee. The ACN will indicate that the asphalt was registered with the approved asphalt source.

For an identical copy of this specification, ask for RS-4366.