APPENDIX AK
SOUND TRANSMISSION
The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance.
SECTION AK101
GENERAL
AK101.1 General.
Wall and floor-ceiling assemblies separating dwelling units, including those separating adjacent townhouse units, shall provide airborne sound insulation for walls, and both airborne and impact sound insulation for floor-ceiling assemblies.
SECTION AK102
AIRBORNE SOUND
AK102.1 General.
Airborne sound insulation for wall and floor-ceiling assemblies shall meet a sound transmission class (STC) rating of 45 where tested in accordance with ASTM E90 or a Normalized Noise Isolation Class (NNIC) rating of 42 where tested in accordance with ASTM E336. Penetrations or openings in construction assemblies for piping; electrical devices; recessed cabinets; bathtubs; soffits; or heating, ventilating or exhaust ducts shall be sealed, lined, insulated or otherwise treated to maintain the required ratings. Dwelling unit entrance doors, which share a common space, shall be tight fitting to the frame and sill.
SECTION AK103
STRUCTURAL-BORNE SOUND
AK103.1 General.
Floor/ceiling assemblies between dwelling units, or between a dwelling unit and a public or service area within a structure, shall have an impact insulation class (IIC) rating of not less than 45 when tested in accordance with ASTM E492 or a Normalized Impact Sound Rating (NISR) of 42 where tested in accordance with ASTM E1007.
SECTION AK104
REFERENCED STANDARDS
AK104.1 General.
See Table AK104.1 for standards thatare referenced in various sections of this appendix. Standards are listed by the standard identification with the effective date, the standard title, and the section or sectionsof this appendix that references the standard.
TABLE AK104.1
REFERENCED STANDARDS