Painting structural steelwork: the complete low down

Painting structural steelwork: the complete low down

Steel is one of the most prevalent materials used in building work. An alloy of carbon, iron and other metals, it’s recognised for its strength, toughness and durability and is common in buildings, bridges, vehicles and so much more. But, as with any other material, despite its numerous strengths, steel does have drawbacks, namely rusting and oxidisation. The prevalence of steel in the building trade mean that many workarounds have been created to combat the shortcomings of structural steel such as the right coverings or paint systems.

Why should I cover/paint structural steelwork?

The reason we cover structural steelwork is to protect its integrity. Steel, like many metals, can be affected by elements such as UV rays, wind, water and mould and if exposed to the elements for long periods of time can become rusted and eventually weakened. One way to protect against this is to shield the outside of the steelwork in a covering of some sort. Paint is the most commonly used material to protect steel. Over the years, dedicated paint systems have been developed to meet the unique demands of structural steelwork.

What paint should I use for steel structures?

Epoxy coatings and polyurethane are usually used as the finishing coat for steel. Epoxies adhere well to steel and provide great corrosion-resistant protection, an added bonus is that minimal surface prep is required (ideal if you’re working on a giant steel structure).

Are there any drawbacks to painting structural steelwork?

Even with industry-standard paint, there will always be possible drawbacks. Paints and their application can be a costly business (although long-term, it will be much better value than having to replace rusted or weakened sections) and over time, paint could fade unevenly. For example, if one area of the painted steel is regularly exposed to sunlight, the colour may fade more quickly than areas that are shaded.

What are the alternatives to paint for covering structural steelwork?

As well as paint, there’s also the option to galvanise steel. Like with paint, galvanising has the benefit of forming a barrier between the underlying steel and the elements. This process is long-lasting and corrosion-resistant but can be prone to chipping, scratching and cracking.

How do you prepare steel for painting?

For the best possible finish and most durable outcome, it’s a good idea to properly prepare the steel before applying paint or galvanizing. Remove loose paint, visible rust or any other foreign matter prior to application by either blast cleaning by wheel or nozzle or for smaller projects, use a power tool to sand and grind.

How do you paint steel?

The method used for painting will vary depending on the surface area that you’re painting but there are many options available including painting by brush, roller or using conventional air spray or airless spray. Airless spray is the most common method for structural steelwork.

Where can I find out more about the type of paintwork I need for my next job?

At Elmbridge, we specialise in industrial coatings, so if you have a job on the horizon and you’d like to talk to an expert about the best way to cover or coat structural steel, get in touch with a member of our team today.