Appeal 9822

Appeal Summary

Status: Decision Rendered

Appeal ID: 9822

Submission Date: 5/24/13 1:25 PM

Hearing Date: 5/29/13

Case #: B-10

Appeal Type: Building

Project Type: commercial

Building/Business Name: Taylor Apartments

Appeal Involves: Erection of a new structure

Proposed use: Multifamily

Project Address: 1110 SE 12th Ave

Appellant Name: John Smith

LUR or Permit Application #: Permit 13-128934-CO

Stories: 4 Occupancy: R-2, M, S-2 Construction Type: V-A

Fire Sprinklers: Yes - NFPA 13 throughout

Plans Examiner/Inspector: Brian Quattlebaum

Plan Submitted Option: pdf   [File 1]   [File 2]   [File 3]

Payment Option: electronic

Appeal Information Sheet

Appeal item 1

Code Section

1207.2 | 1207.3

Requires

1207.2 Air-borne Sound. Walls, partitions, and floor/ceiling assemblies separating dwelling units from each other or from public or service areas shall have a sound transmission class (STC) of not less than 50 (45 if field tested) for air-borne noise when tested in accordance with ASTM E 90.
1207.3 Structure-borne Sound. Floor/ceiling assemblies between dwelling units or between a dwelling unit and a public or service area within the structure shall have an impact insulation class (IIC) rating of not less than 50 (45 if field tested) when tested in accordance with ASTM E 492.

Code Modification or Alternate Requested
Proposed Design

The proposed design is for 4-story wood framed apartment building which includes limited terrace areas over dwelling units at the upper floor (see exhibit 1). The proposed assembly includes a terrace paver/pedestal system, to provide a wear surface and promote drainage, over a fluid applied roofing membrane. Two layers of 5/8” type X gypsum board will be suspended on ½” resilient channels at the dwelling unit side (see exhibit 2 for complete assembly). The provided assembly is engineered to achieve an STC of 53 and an IIC of 52.

Reason for alternative

The assembly is predicated upon providing proper waterproofing of an exterior terrace space over an occupied dwelling unit. Unfortunately, there is limited published sound test data for roof/ceiling assemblies available. Based upon the specific project conditions, the project team was unable to identify listed tests matching this assembly. As the proposed assembly does not match a listed assembly exactly, the plans examiner has requested that the attached engineering analysis be submitted for compliance with the required STC and IIC ratings (see exhibit 3).

The provided analysis indicates that the proposed assembly will exceed the code requirements.

Appeal Decision

1. Sound transmission class rating of roof/ceiling assembly separating the apartment dwelling units from the roof terrace: Granted as proposed.

2. Impact isolation class rating of roof/ceiling assembly separating the apartment dwelling units from the roof terrace: Granted as proposed.

The Administrative Appeal Board finds that the information submitted by the appellant demonstrates that the approved modifications or alternate methods are consistent with the intent of the code; do not lessen health, safety, accessibility, life, fire safety or structural requirements; and that special conditions unique to this project make strict application of those code sections impractical.