A Roof Decking, also known as narrow rib roof deck, provides a wide support surface for various types of rigid insulation and roofing materials. At 36” wide this structural metal transfers horizontal and vertical loads into the building frame. Additionally, A Deck comes in stock lengths of 20’–2”and custom lengths with a primer painted finish.
History of A Roof Decking
When engineers developed type A roof decking and type F roof decking, the engineering community focused on the strength of the metal deck. However, it was only a secondary factor of concern. The primary objective was to maximize the width of the top flange. This would provide the maximum amount of support for the roofing insulation installed on top of the A decking. Over time, roofing materials improved and steel deck manufacturers reduced the width of the top flange. This reduction increased the efficiency of the section from Type A deck to Type F Deck, and finally from Type F deck to Type B deck.
Replacing Type A roof decking in a repair or re-roof application may present some challenges compared to replacing Type B deck. Since the existing narrow rib deck may have a stiffening rib in the top flange, the supports may be spaced farther apart than “modern” Type A decking can span at the same gauge. For example, a roof that was constructed in the 1970’s may have supports at 5’-0” on center with 22 gauge Type A. If new Type A decking is to be installed on this roof, it will need to be 20 gauge, since the maximum span for 22 gauge is only 4’-7”.
Purpose for A Roof Decking
Type A decking is 1-1/2” deep and 36” wide. A decking usually serves as patch material for reroofing projects since more economical types of roof deck are now available.
Engineers designed this low maintenance and high strength roof decking for low-pitched or flat construction. Use A decking on virtually all types of nonresidential buildings: schools, arenas, malls, supermarkets, auditoriums, and similar structures.
Purchase A Roof Decking at Keystar
Keystar Industries A roof decking products meet the required steel deck certifications in accordance with the specifications of the Steel Deck Institute. The material thickness of the A metal deck stocked by Keystar is 20 gauge.
Furthermore, Keystar Industries stocks A deck narrow rib roof deck with a prime painted finish. Keystar’s steel A roof deck products are an economical and convenient choice for any construction roofing or reroofing project.
Choose prime painted grey over bare steel for the most economical finish for type A decking. Typically, this finish provides adequate temporary protection to the base metal of the A metal decking during construction.
Unlike other deck types, type A is rarely used for new construction projects. Rather, use it for repairs and re-roof projects. This is due to the fact that it is the least efficient 1.5” deep steel roof deck type. Compared to Type B deck and Type F roof decks, Type A has the lowest strength-to-weight ratio. As with all steel products, the lighter the section, the more economical. Since A steel deck cannot carry as much load at longer spans as B deck and F deck, the steel supports below the metal deck must be spaced closer together. A smaller support spacing results in more supports and higher construction costs with A decking.
Keystar, the metal deck supplier
Keystar Industries carries metal deck products in a variety of depths, widths, gauges, and finishes. Deck products include roof deck, composite deck, and form deck. Galvanized or primed finishes provide long-lasting, corrosion resistant decking for roofing and flooring requirements in the construction industry. Additionally, Keystar stocks metal decking that meets required steel deck certification in accordance with the Steel Deck Institute’s (SDI) specification.
Whether the need is immediate for a piece of metal deck to patch a rusted area on a roof, or for a variety of deck types for a new office tower, Keystar can satisfy with immediate service, high quality products, and professionalism. Pick up your product at the warehouse in Eagan, MN, or Keystar will coordinate shipping to your job-site.
Keystar stocks metal deck accessories such as cell closures, closure plates, pour stops, foam flute fillers, foam closures, sump pans, welding washers, and TEK screws.