8-19 ACOUSTIC TILE: Contractor shall furnish and install acoustic tile on walls and/or ceilings in the areas shown. Tile shall be prefabricated acoustical units conforming to Federal Specification No. SS-A-118. Units shall be manufactured from either wood or mineral fibers. Unless otherwise shown, tile shall be 3/4 inch in thickness and have a noise reduction coefficient of not less than .70. Tile shall be plain or perforated as noted, shall be 12" x 12" or scored in 12" blocks, shall have beveled butt edges and shall be of the color selected. indicated, Units shall be nailed to furring strips as perforated units to be blind nailed through the corner holes. 8-20, TACKBOARDS: Tackboards or bulletin boards shall be of sizes and at locations shown and shall consist of a cork field or approved color, if available, cemented on plywood backing. Joints shall be flush and shall be concealed as far as practicable; where exposed nailing is necessary, the nails shall be set and the holes filled. The edges of the tack boards shall be finished with a wood trim as detailed. 8-21, MAP BOARDS called for at Building No. 221, location "B™ shall be of similar construction to the tackboards specified in paragraph 8-20 preceding. Map boards shall move on an overhead track, two boards to each track. Arrangement of operating hardware shall be as detailed. Hardware shall include aluminum alloy tracks installed with cadmium plated screws, pressed fiber hanger rollers with roller bearings, other hanger parts to be of plywood; and aluminum door guide angles. Hardware shall be "Har-vey" or approved equal. 8-22. WEATHERSTRIPPING: Contractor shall furnish and install weatherstripping at all openings where called for. Except as otherwise shown, methods and materials shall be similar to those detailed for Bulldings 329 and 330 at Location "B". Rubber stripping for door gaskets shall be 40 to 50 shore synthetic rubber Sponge rubber shall be neoprene or equal synthetic rubber. All metal and angles used for weatherstripping shall be aluminum. All rough hardware shall be of aluminum or shall be cadmium plated ferrous metal. All rubber weatherstripping shall be coated with cement on contact surfaces before being screwed or otherwise secured in place. In locations where vapor-seal coating is called for to be sprayed over interior surfaces, all openings formed by corrugated metal . 8-15