1004 59TH PL SW 2016-01-01 MF Import

Noise Assessment Broidway Apartments Project Michael R. Yantis Associates Inc., P.S. Page 10 APPENDIX 11: Construction for 25 dB Noise Level Reduction At Bedrooms Exterior Walls: (a) Exterior walls, other than as described in this section, shall have a laboratory sound transmission class rating of at least STC-30; or (b) Stud walls shall be at least 4 inches in nominal depth and shall be finished on the outside with solid sheathing under an approved exterior wall finish. 1. Interior surface of the exterior walls shall be of gypsum board or plaster at least 1/2 inch thick, installed on the studs. 2. Continuous composition board, plywood or gypsum board sheathing at least 1/2 inch thick shall cover the exterior side of the wall studs. 3. Sheathing panels shall be covered on the exterior with overlapping building paper. 4, insulation material at least R-11 shall be installed continuously throughout the cavity space behind the exterior sheathing and between wall studs. Insulation shall be glass fiber or mineral wool. (c) Masonry walls having a weight of at least 25 pounds per square foot do not require a furred (stud) interior wall. At least one surface of concrete block walls shall be plastered. Exterior Windows: (a) Windows other than as described in this section shall have a laboratory sound transmission class rating of at least STC-28; or (b) Windows shall be double glazed with panes at least 3/16" thick. (c) Double-glazed windows shall be weather-stripped and airtight when the window is closed so as to conform to an air infiltration test not .o exceed 0.5 cubic foot per minute per foot of crack length in accordance with ASTM E-283- 65-T. (d) Glass shall be scaled in an airtight manner with a non-hardening sealant or a soft elastomer gasket or gasket tape.