Correspondence BARRY LEVIN & ASSOCIATES, Inc.
STRUCTURAL ENGINEERS
Atlanta • Los Angeles • New York • Chicago
May 28, 2009
Greenberg Farrow Architecture
1430 West Peachtree Street, # 200
Atlanta, GA 30309
Attn Mr. Oscar Flores Moreno
BLA Project No.: 208067
Project Name GAP — Washington Square- # 2805 — '.Tigard- OR
Reference: Answer to RFT # 14
Dear Oscar:
Per your request, please find below the answer to the RFI # 14 in regard the installation of the gypsum
board ceiling on the above referenced store located in Tigard, Oregon,
According to the information received from the manufacturer, the specifications of the project and the
architectural drawing A6 -I of the project, this is our understanding of the system that was installed at the
mentioned building
1- Framing of the ceiling provided by "Armstrong World" using a T shape HD 8906 (Armstrong
Catalogue) as a main runner, spaced every four feet on center and running continuously from wall
to wall. The ceiling is suspended from the structure of the roof above, with # 12 SWG galvanized
steel wires every three feet and a continuous wall molding at the perimeter of the ceiling using 20
gauge "L" metal wall angle screwed off with #8 screws every 24" to 32" on center depending on
the stud layout of the wall were attaching to. The cross runners are spaced every 16" on center
using the Armstrong reference shape XL8945 P.
2- The ceiling type used is 5/8 gypsum board attached to framing at the perimeter
According to the governing codes IBC 2006, ASCE 7 -05, the ESR -1289, the Guidelines for Seismic
Restraint for Direct -hung Suspended Ceiling Assemblies (CISCA zones 3 -4) and the Oregon local
requirements this type of ceiling "gypsum board ceiling" is exempt from the lateral force bracing
requirements. Lateral force bracing is the use of vertical struts (compression posts) and splay wires.
Based on the above information, the installation of the referenced ceiling is structurally adequate
If you have any questions, please call . #0:1 PR ,
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Sincerely, �w� 16442P` 2T 'r
Barry Levin and Associates, Inc. 1
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Project Manager Q + °'
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cc. Mr. Bill Bornhorst / Mr Jon Wittlin e. " / RRY _1 - E� ` �
EXPIRATION DATE:
6675 Peachtree Industrial Blvd. • Suite 200 • Atlanta, Georgia 30360
Tel. 770 457 2376 o Fax 770 457 0514 • www BarryLevin corn