Division 7 Ebook Page 556 UL Evaluation Report

Page 9 of 13 6.7 Use as a Water-Resistive Barrier FOAMULAR XPS insulation boards with joints sealed using JointSealR Foam Joint Tape may be used as an alternative to the water-resistive barrier required by IBC Section 1404.2 and IRC Section R703.2 when installed in accordance with this Section. The boards must be covered with an approved exterior wall covering. FOAMULAR XPS insulation boards measuring 2 feet by 8 feet or 4 feet by 8 feet are installed horizontally or vertically with long joints and end joints in contact with one another. When installed directly on framing members, the insulation boards measuring 2 feet by 8 feet must be installed horizontally and framing members are spaced a maximum of 16 inches on center. For wood framing, the insulation boards are attached using 3/8-inch-diameter-head galvanized nails, 1-inch-crown plastic washers or equivalent fasteners long enough to penetrate framing a minimum of inch, or through the sheathing, whichever is less. For steel framing, the insulation boards are attached using No. 6, Type S drywall screws with 1-inch minimum plastic washers long enough to penetrate the framing a minimum of inch. Fasteners must not be over-driven. Fasteners must be spaced a minimum of 12 inches on center around the perimeter and 16 inches on center in the field. For window installations, the nailing flange is set against sealant bedding and fastened to the framing with galvanized roofing nails 3 inches from each corner and 8 inches on center. Minimum 3-inch-wide flashing is used to seal the sills of windows and minimum 2-inch-wide (50.8mm) flashing is used to seal jambs and heads. Window installation must be in accordance with the window manufacturer's instructions. Flashing of flanged window penetrations must be installed in accordance with IBC Section 1405.4. The flashing tape must completely cover the framing sill and extend a minimum of 8 inches (203 mm) up the sides of the opening and 6 inches (152 mm) onto the face of the insulation at the front of the window opening. Joints between boards must be covered by minimum 3 -inch-wide JointSealR Foam Joint Tape positioned using hand pressure, and finished with a roller. Penetrations in exterior walls must be sealed with a sealant complying with ASTM C920, Type S or M, Grade NS, Class 25, or with expanding spray foam sealant complying with AAMA 812 as part of the penetration flashing procedure. When the insulation boards are applied over open framing, vertical butt joints must be over framing members. Horizontal joints of foam plastic boards must be tongue-and-groove, or supported by blocking. For cementitious exterior wall coating systems, unbacked joints are permitted only when specified in an approved cementitious exterior wall coating system. 6.8 Use Under Slabs-on-Ground, Slabs on Decks, Concrete Pavers, and Concrete Pavers on Pedestals: FOAMULAR XPS insulation boards may be used under slabs-on-ground, slabs on decks, concrete pavers, and concrete pavers on pedestals when designed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods. ACI 360 provides guidance for the design of floor slabs installed over insulation as a slab-on-ground. The insulation modulus specified in section 13.2.1 of ACI 360 should be determined based on data provided in Table 3.

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