Section 5160  –– Steel Space Frame Structure

Part 1           General

1.1  Summary

A.       Scope of Work:  The work under this section of the specifications includes all labor, materials, equipment and services necessary to deliver the space frame structure, as shown on the drawings and herein specified, in accordance with the contract documents.

B.        Work of Other Sections:

                                       (1)          Space frame deck

                                       (2)          Space frame insulation and waterproofing

                                       (3)          Space frame skylights

                                       (4)          Supporting structure or edge beam

1.2  Submittals

A.       Drawings:  Submit two paper copies and one set of PDF or AutoCAD files for Architect’s review prior to fabrication.  Drawings must describe the space frame in full in relation to all adjacent work and show all interface details with materials either supported by the space frame or supporting the space frame.  Drawings must be signed and sealed by a Registered Professional Engineer. 

B.        Design Report:  Submit two paper copies and one set of PDF or MS Word files of a design report describing the structural engineering calculations used to design the space frame.  Design report must include all actions on supporting structure for review by project’s engineer.  Design Report must be signed and sealed by a Registered Professional Engineer.

C.       Samples:  Submit sample of a typical tube end and hub with specified finish.

1.3  Quality Assurance

A.       Qualifications: 

                                       (1)          Manufacturer:  The space frame must be manufactured by a firm having a minimum of ten years of experience in the design, engineering, fabrication and construction of metal space frames that are of similar size and complexity to the one for this project. 

                                       (2)          Installer:  The installer of the space frame must be trained by the manufacturer.  All installation work must proceed in accordance to manufacturer’s written instructions and following recommendations of manufacturer’s qualified site consultant.

B.        Design Requirements:

                                       (1)          The structure shall be designed to meet the requirements of the following building code:___________________________

                                       (2)          In addition to the loads specified in the code, the space frame shall be designed to resist the loads of all materials and equipment supported by the space frame, as shown on the drawings, as well as the following loads: _________________________________________________________ _________________________________________________________ _________________________________________________________

1.4  Delivery, Storage and Handling

A.       Wrapping:  All painted structure components shall be individually wrapped at source in a manner that protects the paint finish during transportation, storage and handling. 

B.        Packaging:  All components shall be packaged in metal crates, each weighing no more than 3 tons fully loaded.  Each individual crate shall contain only components immediately adjacent to each other in the finished structure.  Crates shall be numbered to match installation sequence and instructions.  Packing lists shall be affixed to all crates.

C.       Storage at site:  Materials shall be stored off the ground, protected from weather, protected from all sources of water, and secure from leaning or toppling.

1.5  Warranty

A.       The manufacturer shall issue the owner a written guarantee, valid for a period of one year after inspection and acceptance of the work, that the structure is free of defects in materials or manufacture, and further, that any such defects that may arise during this period will be repaired or replaced at no cost to the owner.

Part 2           Products

2.1  Manufacturers

A.       Manufacturer:  Structure will be manufactured by Geometrica, Inc., Houston, TX, (713) 722-7555, http://geometrica.com.

2.2  Materials

A.       Tube components shall be ERW steel tubing meeting or exceeding the mechanical properties of ASTM A500 GR B or equivalent.  Tubes shall be sized by design loads from structural analysis. 

B.        Purlin members shall be ERW formed steel tubing conforming to ASTM A569 or equivalent.  Purlins shall be either fastened to or integral to top chord members.  No secondary cladding support structure shall be permitted.

C.       Hubs shall be aluminum alloy AA6061-T6 solid extrusions with serrated connection slots for the required tube wall thickness.  Hub’s ultimate load under tension shall be at least 120% of the nominal yield strength of the tubes being joined as demonstrated by tests and analysis.   

D.       Threaded hardware shall meet the requirements of either ASTM A-307 or A-449 as required by structural analysis and design.

E.        Other steel components:  Seat Fittings, washers and miscellaneous steel members shall be fabricated from hot rolled steel per ASTM A-36.

2.3  Finish Requirements

A.       Galvanizing:

                                       (1)          Tube and purlin components shall be mill galvanized on both interior and exterior surfaces to ASTM A653, G-90.

                                       (2)          Bolts, washers and other steel hardware, miscellaneous steel fittings and edge framing material shall be hot dip galvanized.

B.        Powdercoat Paint:  Tubes, purlins, seat fittings and washers shall be finished with a baked-on polyester powder coat system over the external galvanizing.  Color as selected by architect from manufacturer’s standard colors.

Part 3           Execution

3.1  Examination

A.       The installer shall examine the space frame supports, work areas and conditions under which the space frame is to be installed prior to assembly and erection.  If the supports area or conditions are unsatisfactory, erection shall not proceed until satisfactory corrections have been made.

3.2  Installation

A.       Manufacturer shall provide a qualified consultant at site during installation.  The site consultant will be available at all times to answer questions about the installation procedures. 

B.        Erection of the metal space frame and related accessories shall be in complete accordance with the manufacturer's installation instructions and following recommendations of manufacturer’s qualified site consultant.

C.       Adequate care shall be taken during the erection sequences to insure members are not positioned by undue force or erected in any manner that cause secondary stresses.

D.       Adequate temporary bracing and supports shall be provided to insure the space frame stability during erection.

E.        Protective wrap shall remain on the tubes through the erection process.

3.3  Clean-Up

A.       Upon completion of this section of work, remove all protective wraps, leave all work and work areas clean and in satisfactory condition.

B.        Immediately after assembly, apply air-dry touch up paint to members whose finish was damaged during material handling or assembly.

C.       Upon completion and inspection (3.4) of space frame work, it shall be the responsibility of the general contractor to protect the space frame from damage during the remainder of construction on the project and until owner acceptance.

3.4  Inspection

A.       The completed Space frame structure shall undergo a full and complete final inspection by manufacturer's site consultant and shall be certified in writing by the manufacturer that the finished product has been erected in accordance with its approved drawings and these contract documents.