Everything You Need To Know About Steel Lintels

Steel lintels are structural components installed over an opening in a wall, like a window or a doorway, to support the loads above the gap and prevent the structure from collapsing. Loadbearing supports like these are used to strengthen the structural integrity of a building and are often mandatory under national building codes.

A mainstay in construction and architecture for their durability and practicality, steel lintels can withstand heavy loads across wide openings without deterioration, thanks to their isotropic properties. 

Isotropic means steel has the same level of strength everywhere. In contrast, timber is anisotropic, meaning its density varies along and across the grain, which is less than ideal for loadbearing purposes.

Compared to timber, steel is much stronger than wood because of its chemical makeup. These same properties make steel the preferred material for lintels for brickwork and other structural applications.

Using Structural Steel Lintels

Although the absence of lintels or poorly installed lintels won’t necessarily mean a pile of rubble where your house used to be. It can still cause enough structural damage to result in rebuilding all over again.

Successful lintel design and installation must consider the load, type of load, structural design of the building, material selection and its required maintenance, moisture control around the opening, and provisions to avoid unwanted movement and installation issues.

However, before we begin, we must stress that only a certified engineer can specify what structural items (including lintels) are used, where and how. Any advice in this article is intended as ‘general content only’, and builders should refer to a qualified structural engineer for specifications and advice for their project.

While we’d love to be able to give you all the information to use structural steel lintels, we cannot offer specifications on which item can and cannot be used. 

The engineer's role is to guide the builder based on various factors we cannot fully explain here.

Types of Lintels

There are different types of structural lintels for brickwork and masonry, including single-angle lintels installed in cavity or veneer walls, steel beams with plates for solid walls, and shelf angles typically used for brick veneer panel walls.

• Loose Angles are laid in the wall and span the entire opening (no lateral support). 

• Combinations are used in solid masonry walls because single loose angles are usually incapable of doing the job. 

• Single-Angles are placed back to back in solid masonry walls.

• Steel Beam/Plates are used in solid walls with large super-imposed loads or walls with openings larger than 2.4 metres.

• Shelf Angles are used in panel wall systems, where the exterior brickwork is supported by shelf angles rigidly attached to the structural frame.

Structural Design

No matter where they are being used, all lintels must meet the structural and serviceability requirements to perform their task successfully. 

Proper lintel design must consider load, stress, and serviceability; otherwise, cracking or spalling (pitting or flaking of bearing material) could occur.

Loadbearing

By its definition, lintels are designed to support the loads above the gap where it is installed. Loads can be described as either uniform or concentrated.

Uniform Loads are forces applied evenly over the length of the support system, i.e. a lintel. Concentrated loads are forces applied at a single point on a beam or structure. 

You must determine the loadbearing before designing for stresses.

Safe Load Tables

Our entire catalogue of lintels and t-bars feature Safe Load Tables so you can quickly determine the total (allowable) load for each of your structural components. Safe Load Tables in Australia are taken from the Australian standards for structural steel.

Stress

Various stresses - flexure, torsion, shear and bearing - can impact loadbearing building materials.

Flexure: how much the supported member can bend.

Combined Flexure and Torsion: how much the supported member can bend and twist.

Shear: are equal forces acting on opposite ends of a supported member.

Bearing: are forces acting on the gap or opening where the lintel is installed.

Serviceability

Different types of lintels have various problems with deflection and rotation and must be analysed for their proper use.

Deflection Limitations: the degree to which a structural element changes shape from an applied load. 

Torsional Limitations: the state of strain in a structural material twisted by an applied torque.

Steel Treatments

What makes steel so versatile is the selection of treatments for different environments and scenarios. Steel treatments are added to provide active or inhibitive corrosion resistance. These include untreated, Zinc phosphate priming, Zinc spray metallising, chemical coating and hot dipping (galvanised steel).

Maintenance

Although steel's isotropic properties make it practically impervious, it is not invincible. Steel lintels must be surface treated - galvanised, primed, or epoxy coated - to prevent corrosion and the appearance of surface rust. Any surface rust should be wiped away immediately, as corrosion can spread throughout the steel, causing it to expand, introducing gaps between the masonry and the lintel.

These gaps can allow water to leak inside and offer pests enough room to take up residence, introducing even more problems. To ensure our steel lintels are free from issues, we apply exterior primer and paint on steel lintels to help protect them from corroding elements.

Steel Lintels From Steel Builders

SMART LINTEL™ - GALVANISED (DOUBLE RIBBED)

Galvanised lightweight lintels to support brickwork structure openings.

Features:

• Hot Dip Galvanised to AS/NZ 4680:2006
• R3 Durability Rating per AS/NZS 2699:2002
• Lightweight when compared to traditional Concrete/Brick Lintels
• Available in a range of sizes.

SMART SHELF ANGLE™

An off-the-shelf item that is suitable for various structural applications.

Features:

• Hot Dip Galvanised to AS/NZ 4680:2006
• Reduced lead time for galvanising
• available in 3-metre lengths with 20mm diameter holes (staggered at 300mm centres) to suit M16 anchor bolts

Contact our office with your requirements if the 3-metre lengths aren't suitable. We can make various hole sizes and positions per your requirements, plus Mitre cuts and welding. 

Fabricated Lintels

Made-to-order products for various structural applications.

Features:

• 130mm stick out
• stitch welding and on both sides of the flat bar 
• flat bar and angle are hot dip galvanised separately and then welded together

Lead times vary depending on stock availability for made-to-order products.

Please allow additional time for your structural steel orders, particularly orders requiring a Galvanised Finish.

Please see our Standard Lead Times page for more information.

Next Day Lintel Dispatch From Steel Builders

Steel Builders supplies a range of off-the-shelf construction lintel solutions available for next-day dispatch across Sydney Metro. Shop with Steel Builders online today to view our entire range of construction lintels for windows and doors. If you require more custom fabrications, contact us directly or request a quote today!

If you'd like to learn more about other Steel Builders products, check out our comprehensive guide on everything you need to know about Parallel Flange Channel, their uses and specifications.