H Beam vs I Beam: What's the Difference?

As universal steel beams are used to support heavy loads, it’s vital to choose the right option for your construction project. The wrong choice could cause a great amount of damage to your construction, and potentially make it unfit for its purpose. Let’s take a look at the most important differences between H and I beams...

Steel H and I beams are both types of RSJ (rolled steel joist). These steel beams are made up of two key parts – the flanges and the web. The flanges refer to the two horizontal planes on either end of the beam, whilst the web refers to the vertical plane between them. The web shields the beam against brute forces, whilst the flanges prevent it from bending.

Generally speaking, steel beams are used to provide structural support to heavy loads within a construction project. This includes providing a full skeleton for a new property, or structural reinforcements for an extension or external wall opening. But which type of steel beam is right for you? There’s a clear difference between H and I beams, and their different qualities can make a big impact on your construction project.

Shape and design

At first glance, there’s a simple way to tell the two types of beam apart. I beams have a much longer web, with the web height being greater than the width of the flanges. They also have tapered edges. This gives them the appearance of a letter “I”. Meanwhile, the web and flanges of an H beam are of similar lengths. This gives them a square shape, resembling a letter “H”.

Construction

Whilst H beams look like they’re made from just one piece of metal, they’re actually constructed from three pieces of metal. These are joined together with bevelled edges. Meanwhile, I beams are constructed from a single piece of steel.

Weight

H beams are considerably heavier than I beams. For projects that require a more lightweight option, I beams are the best choice.

Spans

The spans that steel H beams and I beams can cover varies. I beams are less flexible and may be more suitable for shorter spans. Depending on the specifications, The Metal Store stocks I beams with a span of 1m to 3m. H beams can carry larger loads over longer spans. Our H beams can cover a variety of different spans, including 1m, 1.5m, 2m and 3m.

Centre web

The thicker the web, the stronger the beam. I beams usually feature a much thinner centre web, which means they’re more suitable for lighter loads. In contrast, H beams feature a much thicker web, so they can provide stronger support.

Strength

H beams offer a high level of strength, meaning that they can hold a heavier load. Meanwhile, I beams are usually deeper, so they provide a strong defence against buckling.

Resistance

Steel beams need to carry large loads, so they must be able to resist any bending. As H beams are generally the stronger option, they provide a much more robust defence against bending under pressure.

As an H beam can support more weight over a longer span, this means they’re suitable for use in larger constructions, such as large buildings and bridges. H beams can also withstand tension and compression, making them suitable for supporting vertical loads.

I beams are also used for a variety of construction applications, including providing structure and support for buildings. However, I beams have a much shorter span than H beams. This means they’re more suitable for applications where the available space may be constricted, such as flooring or roofing.

Load

As I beams have a thinner web, they’re more suited to carrying lighter loads. If your project requires steel beams that can hold a larger load, then H beams are the best choice.

Span

H beams can cover longer spans, whilst I beams are more suitable for shorter spans in areas with limited space.

Cost

Whilst H beams are generally more expensive than I beams, they can also be more cost-effective as they can hold larger loads and cover longer spans.

Aside from deciding between H beams and I beams, you also need to be clear as to whether steel is the right material for your project. Steel has a great number of benefits for construction, as it’s durable and corrosion resistant. However, it’s not as fire resistant as other materials, and can be expensive to maintain.

It’s also important to consider any architectural requirements. For example, if you are creating a new external wall opening, there are clear guidelines that require the wall above the opening to be supported by beams. There are also many different building standards that you’ll need to adhere to, such as the NHBC Standards. You should also ensure any steel products you use are fully certified. All our steel beam products have the certification for EN10025 – S355JO.

You should always consult an experienced structural engineer before making a final decision on which type of beam to use. Each project is unique and will have different requirements to consider. For example, you’ll need to be clear on how the beams will be connected, as well as how will they be erected and fabricated on site. You'll also need to have plans in place to protect them from corrosion and degradation over time, and account for any site conditions that may affect the beams, such as the presence of water or other environmental factors.