Mechanically Attached

Apply the bottom layer of approved JM roof insulation with long joints continuous. End joints should be staggered so they are offset at least 12" (305 mm) from the end joints in adjacent rows. Use an approved mechanical fastener of sufficient length to penetrate through or into the deck as required by the specific fastener. Fasteners should be placed in the pattern for the approval desired but never closer than 6" (152 mm) from either edge of the insulation board. On steel decks, the edges of the insulation board that runs parallel to the deck rib must be solidly supported by the ribs. Fasteners are to be driven through the appropriate insulation plates. Care should be taken not to overdrive or underdrive the fastener. Overdriving the fastener will cause the insulation plate to "cup" and can result in inadequate performance. Underdriving can cause the insulation to be loose from the deck.

Firmly set the top layer of approved JM roof insulation, long joints continuous and short joints staggered, into a full width of mopping of hot asphalt (within ±25°F [±14°C] of the EVT). The bitumen should be applied at a nominal rate of 30 Ibs. per square (1.46 kg/m 2 ). All joints must be offset a minimum of 6" (152 mm) between top and bottom layers of insulation.

Apply only as much insulation as can be covered by a complete roof membrane in the same day. Do not leave insulation exposed to the weather.

See Specification 1M for proper fastening of insulation into other deck substrates.