Columns & Base Plates
Porta-King uses all structural steel tubing in all columns. Ranging in size from 6" square up to and including 8" square tubing. Larger column diameters result in greater column rigidity than equal weight columns with smaller sections. Column centers are custom designed to meet loading requirements for your area. Snow, wind and seismic loads will be considered. Centered base plates maximize stability and reduce sway.
Beams
We use all wide flange beams which are by design symetrical and concentrate steel at the flanges and radii to provide the greatest strength and point load capacity.
Connections
The standard beam to beam or purlin to girder connection is a Type 2 connection. A very strong connection providing superior strength throughout the structure.
All attachment angles, tees and seats are fully welded to attachment components. This eliminates confusion created when all of these components ship loose for installation on site. Factory installation of all of these components dramatically reduces installation time. All components to be galvanized for exterior use.
Bar Grate 1" x 1/8"
A strong and economical deck material, bar grating allows for air movement, light, snow, ice and rain water to pass through deck surface. Nominal 1" x 4" opening. Galvanized finish is standard. Consult your local building department for more information (NAAMM). Galvanized Bar grate is also used on stair treads and landing surfaces.
Stair Design
Stair assembly will have treads factory welded to stringers. Stair width shall not be less than 36". Treads will be designed such that the openings between treads is less than 4 inches creating a closed design. Completely closed "Solid Risers" as defined by the IBC are only required when safe egress for people with disabilities is a facility or local code requirement . Maximum rise per tread shall not exceed 7". Minimum run per tread shall not be less than 11". Stair shall maintain a minimum headroom clearance of 6’-8". Stringer and tread components shall have a chemistry, which equals or exceeds that of ASTM A36 requirements. The stair stringers will be a minimum of MC10x8.4. The treads will be steel treadplate with a minimum thickness of 12 gauge, formed to facilitate a "closed" riser. All components shall be galvanized for exterior use.
Guard rail will be a 42" high, two-rail design and maintain a minimum clearance between rails. All railing shall have a minimum of a 4" high kickplate. Guard rail shall be assembled at the factory to be comprised as a welded, one-piece assembly. The guardrail shall fasten directly to the tower deck to achieve maximum strength and rigidity. The chemistry will equal or exceed that of ASTM A500-Grade B requirements. All rails will be 1 ½" square tubing. Guardrails to be surfaced mounted to the deck surface without the intrusion of columns protruding through the deck surface. All guardrails shall be fastened to the deck surface using 3/8" bolts.
In some instances the guard rail will be designed to meet additional requirements such as "Public Access" where a 4" sphere may not pass between the balusters. Or a 3 rail design that meets different code requirements for areas that do not use the IBC code to the letter. All components to be galvanized for exterior use.
