3GIC. CSI 3-Part Specifications.

Built-Up Roofing Specifications

Three Ply Mineral Surfaced Fiber Glass Built-Up Roof. For use over JM insulation, approved decks or other approved insulations, on inclines of ¼" to 6" per foot (20.8 to 500 mm/m).

For Region 3 only

General

This specification is for use over any type of approved structural deck which is not nailable and which offers a suitable surface to receive the roof. Poured and pre-cast concrete decks require priming with JM Concrete Primer prior to application of hot asphalt.

This specification is also for use over JM roof insulations or other approved rigid roof insulations, which are not nailable and which offer a suitable surface to install the roof. Specific written approval is required for any roof insulation not manufactured or supplied by JM. Insulation should be installed in accordance with the appropriate JM Insulation Specification detailed in the current 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 directly over poured or pre-cast gypsum or lightweight, insulating concrete fills.

Design and installation of the deck and/or substrate must result in the roof draining freely and 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 are not eligible to receive a JM Roofing Systems Guarantee.

Note: All general instructions contained in the current JM Commercial/Industrial Roofing Systems Manual should 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

Note: On roof decks with slopes up to 1" per foot (83.3 mm/m), the roofing felts may be installed either perpendicular or parallel to the roof incline. On slopes over 1" per foot (83.3 mm/m), refer to Paragraph 6.11 of this section for special requirements.

Using GlasPly Premier or GlasPly IV, apply a piece 18" (457 mm) wide, then over that, a full width piece. The following felts are to be applied full width overlapping the preceding felts by 19" (483 mm) so that at least 2 plies of felt cover the base felt/substrate at all locations. Install each felt so that it is firmly and uniformly set, without voids, into the hot asphalt (within ±25°F [±14°C] of the EVT) applied just before the felt at a nominal rate of 23 lbs. per square (1.1 kg.m²) over the entire surface. Installation over porous substrates such as roof insulation may require up to 33 lbs. per square (1.6 kg/m²) of hot asphalt.

Surfacing

Prior to application of GlasKap, cut the cap sheet into handleable lengths (12' - 18' [3.66 m - 5.50 m]). Lay the material out on the roof and allow it to relax and flatten. To accommodate a full width sheet, apply a mopping of hot asphalt, approximately 20°F (11°C) above the EVT, at a nominal rate of 23 lbs. per square (1.1 kg/m²). (The higher temperature of asphalt maximizes the bonding of the cap sheet to the ply felts.) Then flop the cap sheet into the hot asphalt. On subsequent courses, the cap sheet is positioned upside down, directly over the sheet in the preceding course such that the side lap area of the preceding sheet is exposed. Care should be taken to maintain 2" (51 mm) side laps and 6" (152 mm) end laps. Asphalt is applied in the same manner as before, making sure to also cover the 2" (51 mm) exposed side lap. Asphalt may also be applied to the exposed "upside down" cap sheet, prior to "flopping" it into the hot asphalt. The cap sheet must be firmly and uniformly set, without voids, into the hot asphalt with all edges and laps well sealed.

Asphalt

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.

Check with a JM Technical Services Specialist for special asphalt requirements in hot climates.

For an identical copy of this specification, ask for RS-2047.