Johns Manville
3CIS-W/3PIS-W (Alternate). CSI 3-Part Specifications.
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APP Modified Bitumen Specifications |
Specification 3CIS-W/3PIS-W (Alternate) |
Three Ply (Two Ply Asphalt, One Ply Heat Welded) Modified Bitumen Smooth Surfaced Roofing System. For use over Johns Manville (JM) insulation, approved decks, or other approved insulations on inclines up to 3" per foot (250 mm/m). For Regions 1, 2 and 3 |
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 asphalt. 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" (458 mm) wide piece of one of the intermediate plies listed into a full mopping of bitumen. Over that, apply a full width piece. The remaining plies are to be applied full width, overlapping the previous plies by 19" (483 mm), so that at least 2 plies cover the substrate at all locations. 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.
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 shee