|
contents | news | |||||||||
| Low maintenance outdoor spiral stairs from Salter  Salter Industries has two low maintenance options for builders' outdoor applications. The firs is hot dipped galvanized steel. This special metallurgical finish applied to solid steel costs slightly more initially, but it lasts much longer. Under normal circumstances, there shouldn’t be any maintenance or touch up required for 50 years or longer. There are two ways to protect steel from corrosion: barrier and cathodic. Paint is an example of barrier protection – it simply shields the surface from the environment. Any scratch, penetration or pinhole compromises the coating and allows the corrosion of the underlying steel to begin.Galvanizing or dipping the steel in molten zinc which then metallurgically bonds to the steel is a form of cathodic protection. The zinc acts as the anodic area on the steel. As the anode, the zinc preferentially corrodes, keeping the cathode or base steel intact. Known as 'galvanic protection', only galvanizing offers this cost-saving combined cathodic barrier protection for steel. Galvanizing weathers to a soft gray finish that prevents rust and corrosion for fifty years or more, even in harsh ocean air environments. Because galvanizing is a total immersion process, all parts of the fabricated steel are coated and protected both inside and outside, including areas where paint – either sprayed or brushed on – can’t reach. And because zinc will only metallurigically bond to clean steel, any uncoated steel is immediately apparent as the work is withdrawn from the molten zinc bath. This allows for prompt repair, ensuring the components are completely covered and the coating has total integrity. If the preference is stairs in a specific color, the galvanized stair can be painted using the proper primer. Galvanizing will greatly increase the life cycle of the paint and reduce the need to repaint the stair in the future. Or the stairs come in powder coated aluminum. Exterior applications require staircases that are going to stand up to the weather without constant maintenance. Aluminum is a tough, durable metal that does not rust, making it an ideal choice for an exterior stair from a deck or balcony. Although it is more expensive than galvanized, it offers the same long-term easy maintenance. Aluminum staircases come two ways: primed or factory finished. The primed stair needs to be painted on the job site after installation. The factory finished stair uses a baked on 'powder coating' process and is available in white, black or custom colors and textures. For the factory finish, the unassembled fabricated stair kit goes through a 5-stage wash process to prepare the aluminum. The paint is a fine powder with the consistency of flour. It is applied to the aluminum with an electrostatic charge for even coverage. It is then baked in an oven at 350°F causing the powder to gel and then cure into a durable finish. All welds are hidden under the stair for sharp seams. And the stairs have the same specs as our steel stairs. Stainless steel hardware is included to prevent rusting. If the preference is a more rustic look, optional cedar treads and/or a 1-piece handrail is also available. write your comments about the article :: © 2006 Construction News :: home page |