PART 1 - GENERAL
1.01 GENERAL REQUIREMENTS
A. Attention is directed to the Contract and General conditions and all Sections within Division 1 – GENERAL REQUIREMENTS, which are hereby made a part of this Section of the Specifications.
B. Examine all other Sections of the Specifications for requirements that affect work of this Section whether or not such work is specifically mentioned in this Section.
C. Coordinate work with that of all other trades affecting, or affected by work of this Section. Cooperate with such trades to assure the steady progress of all work under the Contract.
1.02 SUMMARY
A. This Section includes the following:
1. Rooftop acoustical screens.
B. Related Sections include the following:
1. Section 05120 – STRUCTURAL STEEL, for steel elements for support of acoustical screens in addition to those specified herein.
2. Section 07530 – EPDM MEMBRANE ROOFING, for roofing, membrane flashing and associated materials.
3. Section xxxxx – xxxxx
1.03 PERFORMANCE REQUIREMENTS
A. Structural Performance: Provide screens capable of withstanding the effects of gravity loads and the following loads and stresses within limits and under conditions indicated without permanent deformation of acoustical screen components, noise or metal fatigue caused by acoustical screen blade rattle or flutter, or permanent damage to fasteners and anchors. Wind pressures shall be considered to act on vertical projection of acoustical screens.
1. Wind Loads: Determine loads based on a uniform pressure of 35 lbs./sq. ft. (1675 Pa), acting inward or outward.
B. Seismic Performance: Provide acoustical screens capable of withstanding the effects of earthquake motions determined according to Massachusetts State Building Code.
C. Thermal Movements: Provide acoustical screens that allow for thermal movements resulting from the following maximum change (range) in ambient and surface temperatures by preventing buckling, opening of joints, overstressing of components, failure of connections, and other detrimental effects. Base engineering calculation on surface temperatures of materials due to both solar heat gain and nighttime-sky heat loss.
1. Temperature Change (Range): 120 deg. F. (67 deg. C), ambient; 180 deg. F. (100 deg. C), material surfaces.
D. Airborne Sound Transmission Loss: Provide acoustical screens complying with airborne sound transmission loss ratings indicated, as demonstrated by testing manufacturer’s stock units identical to those specified, except for length and width.
1. Airborne Sound Transmission Loss: STC 42 and the following minimum sound transmission loss values per ASTM E 413, determined by testing per ASTM E 90.
Frequency (Hz) / 63 / 125 / 250 / 500 / 1000 / 2000 / 4000 / 8000Transmission
Loss / 21 / 21 / 30 / 41 / 52 / 59 / 64 / 67
2. Noise Reduction Coefficient: NRC 1.0 and the following minimum sound absorption coefficients per ASTM C 423:
Frequency (Hz) / 63 / 125 / 250 / 500 / 1000 / 2000 / 4000 / 8000Absorption Coefficient / .18 / .75 / 1.02 / 1.07 / .98 / .89 / .80 / .86
1.04 SUBMITTALS
A. Prepare and submit the following submittals in accordance with the requirements of Section 01300 – Submittals.
B. Product Data: For each type of product indicated.
C. Shop Drawings: For acoustical screens and accessories. Include plans, elevations, sections, details, and attachments to other Work. Show panel profiles and spacing.
1. For installed acoustical screens indicated to comply with design loads, include structural analysis data signed and sealed by the qualified professional engineer responsible for their preparation.
D. Samples for Initial Selection: For units with factory-applied color finishes.
E. Samples for Verification: For each type of metal finish required.
F. Product Test Reports: Based on evaluation of comprehensive tests performed by an independent qualified testing agency or by manufacturer and witnessed by a qualified independent testing agency, for each type of acoustical screen.
G. Erector Certificate: Signed by acoustic screen manufacturer certifying that Erector is approved, authorized, or licensed by manufacturer to install acoustical screen.
H. Manufacturer Certificate: Signed by manufacturer certifying that products comply with requirements.
1.05 QUALITY ASSURANCE
A. Erector Qualifications: An experienced erector who has specialized in erecting and installing work similar in material, design, and extent to that indicated for this Project and who is acceptable to manufacturer.
B. Engineering Responsibility: Preparation of Shop Drawings and comprehensive engineering analysis by a qualified professional engineer.
C. Welding: Qualify procedures and personnel according to the following:
1. AWS D1.3, “Structural Welding Code – Sheet Steel.”
D. SMACNA Standard: Comply with recommendations in SMACNA’s “Architectural Sheet Metal Manual” for fabrication, construction details, and installation procedures.
E. Inspector Qualifications: The acoustical screen installation shall be inspected by a representative of the approved acoustical screen manufacturer fully qualified to perform inspections.
1.06 PROJECT CONDITIONS
A. Field Measurements: Verify acoustical screen dimensions by field measurements before fabrication and indicate measurements on Shop Drawings.
PART 2 - PRODUCTS
2.01 MANUFACTURERS
A. Available Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:
1. Acoustical screens:
a. George Koch Sons, LLC Evansville, IN
b. Approved substitution
c. Approved substitution
B. Basis-of-Design Product: The design for the acoustical screens for this Project is based on Koch Acoustical Barriers manufactured by Koch Sons, LLC. Subject to compliance with requirements, provide either the named product or a comparable product by one of the other manufacturers specified.
2.02 MATERIALS
A. Galvanized Steel Sheet: ASTM A 653/A 653M, G90 (Z275) zinc coating, mill phosphatized.
B. Steel shapes, plates and bars shall conform to the requirements of Standard Specification for Steel for Bridges and Buildings, ASTM A36.
C. Fasteners for Acoustical Panels: Self-tapping screws, bolts, nuts, self-locking rivets and bolts, end-welded studs, and other suitable fasteners designed to withstand design loads.
1. Self-drilling Type 410 stainless steel or self-tapping Type 304 stainless steel or zinc-alloy-steel hex washer head, with EPDM or PVC washer under heads of fasteners bearing on weather side of metal panels.
2. Steel bolts and nuts shall conform to ASTM B-6.
D. Non-Shrink Grout: Hydraulic cement for installing bolts and fastenings into masonry and concrete and for setting pipe posts into sleeves and cements; quick setting, non-staining, non-shrinking exterior type, as approved.
E. Bituminous Paint: Cold-applied asphalt emulsion complying with ASTM D 1187.
2.03 ACOUSTICAL PANELS
A. Formed metal sound barrier and absorption panels: Partially perforated, formed metal panels with acoustical insulation core, secured to steel frame.
1. Panel Dimensions:
a. Width: 33 inches (838 mm).
b. Length: As shown on Drawings
c. Depth: 4 inch (102 mm).
B. Construction: Exterior and interior galvanized steel shells mechanically fastened and spot-welded to internal channel frame.
1. Internal Frame: Galvanized steel channels with configuration and spacing required to comply with structural requirements.
2. Vertical Edges: Provide roll-formed edge profile for tongue-and-groove joints between adjacent panels.
C. Solid Exterior Shell: Roll-formed, galvanized steel sheet, of thickness required to comply with structural performance requirements, but not less than 0.048-inch (1.2 mm) nominal thickness (18 gage).
D. Perforated Interior Shell: Roll-formed, galvanized steel sheet, of thickness required to comply with structural performance requirements, but not less than 0.030-inch (0.76 mm) nominal thickness (22 gage).
1. Perforations: 3/32-inch (2.4 mm) diameter perforations, staggered spacing 3/16-inch (4.8 mm) on center.
E. Cap: Factory formed channel formed to cover top surface of top panel, with powder coat finish to match panels.
F. Base: Factory formed channel to cover bottom surface of panel with weep penetrations for self drainage, powder coat finished to match panels.
G. Corner: Factory-formed corner trim powder coat finished to match panels.
H. Accessories: Manufacturer’s standard accessories and trim as required for complete installation.
I. Acoustical Insulation: Mineral-fiber, rigid-board insulation in conformance with HH-1-558B and ASTM E-136, and with the following properties:
1. Density: 4 pounds per cubic foot.
2. Water Absorption: Less than 1%; non-hygroscopic and resistant to water wicking.
3. Melting Temperature: Greater than 2,000 degrees F.
4. Flame spread less than 15, and smoke development of 0, when tested according to ASTM E 84.
5. Noncombustible in accordance with STM E 136.
J. Basis-of-Design Product: George Koch Sons, LLC, Koch Acoustical Panel System, or equal product of an approved manufacturer.
2.04 STRUCTURAL FRAME
A. Frame: Refer to Section 05210 – STRUCTURAL STEEL, for structural steel sections including tubular steel posts, base plates, channels and retaining angles, bolted as required to support loads specified herein.
1. Finish for Frame: Galvanize, shop-prime and shop finish frame and fasteners in accordance with the requirements for finishes specified in Section 05500 – Miscellaneous Metal Work.
2.05 FABRICATION
A. Shop and Field Connections:
1. Shop connections shall be welded or riveted, and field connections bolted unless otherwise indicated.
2. Use flat head countersunk rivets finished flush where riveted connections are exposed to view in finished work.
3. Bolts shall be turned up tight and threads deformed to prevent loosening.
B. Include supports, anchorages, and accessories required for complete assembly.
C. Joints and connections exposed to weather shall be formed to exclude water.
2.06 FINISHES
A. Comply with NAAMM’s “Metal Finishes Manual for Architectural and Metal Products” for recommendations for applying and designating finishes.
B. Finish acoustical panels in shop prior to assembly and acoustic insulation fill.
C. Surface Preparation: Clean surfaces of dirt, grease, and other contaminants. Clean welds, mechanical connections, and abraded areas and repair galvanizing according to ASTM A 780. Apply a conversion coating suited to the organic coating to be applied over it.
D. Powder-Coated Finish: Prepare, treat, and coat galvanized metal acoustical screens to comply with resin manufacturer’s written instructions and as follows:
1. Prepare panels by thoroughly removing grease, dirt, oil, flux, and other foreign matter.
2. Treat prepared acoustical screens with zinc-phosphate pretreatment, rinse, and seal surfaces.
3. Apply thermosetting polyester or acrylic urethane powder coating with cured-film thickness not less than 3.0 mils (0.08mm).
4. Color and Gloss: As selected by Architect from manufacturer’s full range.
E. Surface Protection: Apply temporary 3.0 mil thickness PVC temporary covering to powder coated surface after cure for shipment and installation protection.
PART 3 - EXECUTION
3.01 EXAMINATION
A. Examine structural frame, with Installer present, for compliance with requirements for installation tolerances and other conditions affecting performance.
1. Proceed with installation only after unsatisfactory conditions have been corrected.
3.02 INSTALLATION
A. Install panels on structural frames as shown on approved shop drawings, so that top edge of acoustical screen is level, with adjacent panels aligned for smooth, continuous appearance. Install components in accordance with approved shop drawings and manufacturer’s recommendations.
B. Form closely fitted joints with exposed connections accurately located and secured.
C. Repair finishes damaged by cutting, welding, soldering, and grinding. Restore finishes so no evidence remains of corrective work. Return items that cannot be refinished in the field to the factory, make required alterations, and refinish entire unit or provide new units.
D. Protect galvanized and nonferrous-metal surfaces from corrosion or galvanic action by applying a heavy coating of bituminous paint on surfaces that will be in contact with concrete, masonry, or dissimilar metals.
3.03 ADJUSTING AND CLEANING
A. Remove temporary PVC covering during installation.
B. Clean exposed surfaces of acoustical screens that are not protected by temporary covering, to remove fingerprints and soil during construction period. Do not let soil accumulate until final cleaning.
C. Before final inspection, clean exposed surfaces with water and a mild soap or detergent not harmful to finishes. Thoroughly rinse surfaces and dry.
D. Restore acoustical screens damaged during installation and construction so no evidence remains of corrective work. If results of restoration are unsuccessful, as determined by Architect, remove damaged units and replace with new units.
1. Touch up minor abrasions in finishes with air-dried coating that matches color and gloss of, and is compatible with, factory-applied finish coating.
END OF SECTION 13080
Koch Acoustical Barrier Specification, Page 8 of 8