Also known as I-beams or H-beams, RSJ steel beams are built by rolling a single piece of structural steel. This helps to maintain their structural integrity and are ideal for supporting walls and floors where the underlying requirement is building an extension or creating an opening in a load-bearing wall.

RSJ beams have excellent corrosion resistance, weldability properties and impressive machinability. If you look closely at the table above, you’ll notice that the rolled steel joists sizes are show in depth or thickness (web), width (flange) and weight (kg). The thickness (sometimes called height) and width, for example, are measured as if you’re looking at a capital ‘I’, and that’s why RSJs are also called I-beams. As you can see, different thicknesses are available for the web and flange according to the size you require.

The web is what aids in resisting sheer forces, while the flanges play the role of resisting the larger, more complex part of the bending moment which is placed on the RSJs. These are great for making retaining walls in, say, landscape gardening, where you’d place wooden sleepers between them, and also to construct the frames of industrial warehouses and modern office blocks.

Perhaps, one of the most common uses of I-beams or H-beams is for holding up supporting walls. They are designed specifically for strength and load bearing, which is why they have tapered flanges available in different thicknesses. They’re also available in a broad range of sizes, which is typical of RSJ steel beams, making them ideal for all kinds of low storey building projects. They provide excellent strength to girders and support to joists when building ceilings and floors.