1.  General

Acoustical panels and related accessories shall be provided as hereinafter described. Unless specifically indicated otherwise, it is expected that the supplier will provide all components, supports, hardware etc., as may be required for a complete and proper installation as established by the engineer.

2. Materials

Reflective panels shall be constructed of sheet 18 gauge thickness or as specified conforming to the structural quality and shall be galvanized in accordance with ASTM A-653, Class G-90. Flashing and caps shall be fabricated using sheet steel 18 gauge, with a minimum thickness of 22 gauge and shall be galvanized in accordance with ASTM A-653, Class G-90.

Coatings, when required, shall be applied to the panels as detailed on the drawings and schedule. All coatings shall be applied after galvanizing. Total coating thickness on exposed surfaces shall be a minimum of 1.0 mil. Galvanized surfaces to be coated shall be cleaned and pretreated prior to priming.

All structural supports and girths, when provided, shall be hot-rolled, wide flange steel beams, in accordance with ASTM A-36. Structural supports shall be hot-dipped galvanized, in accordance with ASTM A-123, except that there shall be a 2 ounce total coating weight on all sides.

All screw fasteners shall be self-tapping or self-drilling and zinc plated or stainless steel where required. Bolts and nuts shall conform to ASTM A-307 and shall be galvanized in accordance with ASTM A-164.

3. Construction

Each reflective panel shall be a minimum of 12 inches wide, and shall be designed to interlock with adjacent panels. Panels shall be suitable for horizontal or vertical mounting.

Intermediate girths, if required, shall be furnished and installed in accordance with the panel manufacturers recommendations. When wind load is a factor, supports shall be sized in accordance with AASHTO standards.

4. Performance

Typical samples of all acoustical panels shall be tested in an independent laboratory and shall have performance data available for evaluation.

When tested in accordance with ASTM E-90, the sound transmission class of a reflective panel shall have a value of at least STC-22. The one-third octave band sound transmission loss value shall not be less than those shown in the following table: