Steel buildings are widely used across industries due to their strength. However, despite their robust nature, steel structures require proper maintenance to prevent rust, corrosion and weather damage.
Painting steel buildings not only protects the metal but also extends the building’s lifespan. In this guide, we cover everything you need to know about painting steel buildings effectively and choosing the best steel paint for your structure.
Why Paint Steel Buildings?
Steel buildings are strong and durable, which is why they’re used in so many industries, such as farming, manufacturing, warehouses and commercial spaces. However, even steel needs protection. Over time, exposure to sun, rain, wind and mould can cause rust and weaken the structure. Applying steel paint protects your building and preserves its integrity.
- Protect Against Rust: Unpainted or poorly maintained metal can corrode.
- Extend Building Lifespan: Paint adds a layer of protection against water and UV damage.
- Improve Appearance: A fresh coat of paint transforms the look of your property.
- Increase Property Value: A well-maintained exterior makes your building more attractive to buyers or tenants.
Types of Steel Structures That Can Be Painted
- Industrial warehouses
- Agricultural buildings (barns, grain sheds)
- Commercial garages and workshops
- Storage units and shipping containers
- Bridges and structural frames
What Paint Should I Use for a Steel Building?
When selecting steel building paint, consider the surface and environmental factors. Here are three popular options for painting steel buildings:
Single Pack Primers
Zinc Phosphate Primer serves as a good protective base coat for steel buildings. For extra anti-corrosive protection Zinc Rich primers contain a higher amount of zinc dust to guard against corrosion. The zinc corrodes first, acting as a sacrificial layer that protects the underlying steel from rust and damage.
Epoxy Paints
There are many different epoxy steel primers available, including Zinc Phosphate, Zinc Rich, and Micaceous Iron Oxide (MIO) primers. These offer excellent anti-corrosive protection especially in industrial settings or harsh coastal environments where extra resistance to salt water is needed.
When applied correctly as part of a complete system with an epoxy primer and epoxy top coat, they create a tough, moisture sealing surface that can withstand heavy wear, making them ideal for steel walls and high-traffic areas.
Although epoxies provide exceptional protection and durability, their top coats do not have UV resistance. This means the colour will chalk and fade over time; however, this does not affect the overall quality or protective performance of the coating.
QAD Direct to Metal Paint
QAD direct to metal paint provides a clean, semi-gloss finish that holds up well on structural steel and exterior trims. It can be used directly to metal as it has anti corrosive properties, saving time and money without needing to use a primer. While it can go straight onto metal, for harsh environments a primer may be used to give it better anti-corrosive protection. It’s a smart pick when you want a long-lasting, polished look with minimal maintenance.
How to Prepare the Structure for Paint
Effective preparation is key to a long-lasting paint job on steel buildings:
- Clean the Surface: Remove grease, dirt and loose particles using a degreaser. For previously painted areas, lightly sand and wipe down for better paint adhesion.
- Remove Loose Paint: Use wire brushes, sanding or power tools to get rid of peeling paint. Avoid over-polishing the metal to prevent adhesion problems.
- Remove Rust: Brush or sand off loose rust, for heavy rust or mill scale, sandblasting or grinding may be needed.
- Prime Immediately: Once the metal is dry after cleaning apply the right primer straight away to prevent flash rust. Use rust-inhibiting primer on exposed metal or screw heads and spot-prime or apply a full coat depending on the building’s condition.
Steel Paint Application Methods
The method you choose for painting steel buildings affects speed, finish quality, durability and overall cost. Spray painting and brush-and-roll are the most common techniques.
Spray Painting
Advantages: Spray painting steel buildings is fast and efficient, perfect for large surfaces, producing a smooth, factory-like finish without brush marks. It also reaches tricky areas like high ceilings and tight corners easily. The best spray paint system to use for steel buildings is an airless paint sprayer, which provides an even coverage on large surfaces.
Considerations: Overspray can be messy, requiring masking and careful handling, plus the equipment and paint use are more costly.
Brush and Roll Painting
Advantages: Brushes and rollers apply thicker coats of steel building paint, improving durability and protection, especially in harsh weather. It offers better control for detailed areas and uses less paint, making it more budget-friendly.
Considerations: It’s slower, more labour-intensive and rollers may struggle with very textured surfaces, leaving some unevenness in the finish.
Masking and Spraying Techniques
- Mask off trim, windows or any features you don’t want painted.
- Paint trim first with an angled spray pattern.
- Then mask it and spray the siding using wide horizontal passes.
- Work in sections to prevent lap marks and overspray.
Tips for Best Results
- Paint steel buildings in low-humidity weather with no rain forecast for at least 48 hours.
- Pull masking off while the paint is still wet to avoid tearing or peeling.
- Painting is messy, so wear PPE and any RPE if you are spraying.
Steel Paint at Black Country Paints
When it comes to protecting your steel building, choosing the right paint and materials is important. At Black Country Paints, we offer a wide range of premium steel coatings, including zinc-rich primers, epoxy paints and durable enamels designed to withstand harsh weather and industrial wear.
We also stock the necessary equipment you will need when you’re painting steel buildings, such as spraying equipment, paint cleaners and gloves.
Visit Black Country Paints today or contact us for expert support on your next steel painting project.
