Beams & Columns

About Beams and Columns

Structural and framing elements are what holds the building together. In that category, beams and columns represent two of the most important components. Their substantial role in keeping the construction stable and safe reflects in balancing the overall weight and transferring forces throughout the structure towards the foundations and down the ground. 

In New Zealand, beams and columns are often made from the same materials. However, their design is not identical, and they serve different functions. Beams are, by definition, horizontal and designed to support the weight of floors and roofs, providing a better balance and shifting the load towards vertical load-bearing elements such as columns. Sometimes bigger and heavier beams called transfer beams are used to support the cumulative weight of stacked walls or other beams and transfer the load to the supports.

Applications

• Commercial and industrial: Structural steel beams and columns are often used in high-rise buildings in New Zealand, especially ones relying entirely on steel framing. They are quick to produce, easy to use, durable, and lightweight, featuring superior tensile strength at the same time.
• Residential buildings: Structural beams and columns are regular parts of houses and apartment buildings. For the same set of advantages, steel beams and columns are sometimes preferred over other choices in New Zealand. They provide solid, steady reinforcement.
• Bridges: Lightweight with a substantial strength-to-weight ratio, steel beams are an excellent solution for withstanding large loads and perpetual heavy traffic. 
• Various uses: Different kinds of bespoke structural frames include specifically designed beams and columns. 

Types of Beams and Columns

In New Zealand, beams and columns design determine their installation method and the level of support they will provide. The types are typically distinguished by the profile and often named by their appearance. 

Some of the most common bean types in New Zealand include:

• I beam: This is the most common type, also called universal beam and characterised by the resemblance to the letter “I”.
• PFC: Parallel flange channel or “C” channel beam is shaped as a half of an I beam, with sloped inner flanges.  
• H beams:-Similar in shape but longer and heavier than steel I beams, this type is designed with an ‘H’-shaped cross-section that earned its name. 
• W beams: The name comes from “wide flange beams”.  
• T beams: The T-beam is characterised by a vertical web, flange at the top, and a ‘T’-shaped cross-section.
• RSJ beams: The “RSJ” or “rolled steel joists” are typically no different from universal steel beams.

Typical column types in New Zealand:

• Square/Rectangular: The common type, easy and cost-effective to produce. Square and rectangular models are often used in the construction of buildings and other heavy structures.
• Circular: Used for aesthetical as much as functional reasons, this type is typically found in the elevation of the buildings or as bridge pillars. Their bending resistance is normally higher than the rectangular or square columns.
• L and T column: L-shaped column similar in properties to rectangular/square model, but applied in the corners. In contrast, the T-shaped column can be used according to the specific design requirements of a structure.

Based on the reinforcement, the columns can be divided into tied, spiral, and composite. Load type categorisation distinguishes axially loaded, uniaxial eccentrically loaded, and biaxial eccentrically loaded columns.

Beam Construction Materials

Timber Beam

In New Zealand, timber beams are commonly used in wooden roof structures alongside posts and columns, providing additional support to the frame, although their longevity and strength require careful maintenance and care. Hardwood beams or other types of wood can be used

Steel Beam

Structural steel is an excellent material for beams and columns, being durable, strong, durable and higher in strength compared to most other construction materials. Steel beams can be found in a variety of construction applications, from bridges to roofing.  

Reinforced Concrete Beam

Reinforced concrete beams have long been a staple structural element in New Zealand due to their ability to carry transverse external loads. This type features steel reinforcement taking over the tensile stress, the beam suitable for supporting loads such as heavy slabs, masonry blocks in the walls, columns, and other elements.

Composite Beam

A composite beam is designed by using two different materials, such as a combination of steel and concrete, complementing each other as a unit.

Column Construction Materials 

House columns can be constructed from a variety of materials including stone, concrete, and metal, and can be used as both exterior and interior features in buildings.

Reinforced Concrete Column

Similarly to a reinforced concrete beam, this column features a steel core to augment its tension capacity.

Steel Column

A steel column is comparatively stronger, more flexible, and durable than most other conventional materials in New Zealand.

Timber Column

Wooden columns are today featured mostly in traditional or rustic style buildings, due to their aesthetic properties. 

Brick Column

Brick columns support and increase the stability of the masonry structures. They are available in a variety of cross-sections in New Zealand from rectangle to elliptical.

Block Column

Typically constructed from AAC block or cement concrete block, these columns carry less of their own structural weight compared to their counterparts made from concrete.

Stone Column

Mostly used for aesthetic reasons, these columns are made from different stones and rubble.

Limestone columns are used for decorative or structural purposes and are commonly found in architecture and landscaping.

Things to Consider Before Buying Beams and Columns

In high-rise structures where beams and columns bear substantial loads, steel or concrete are the best materials to use.

Each floor bears the weight of columns and other structural elements placed above. For that reason, the columns of the bottom floor should be large enough to carry substantial weight respectively accumulated throughout the floors. Also, it’s best to place them as consistently as possible on all floors for the most efficient support.