Metal Purlins: What Role Do They Play in Roofing and Construction?

Reports show that new construction projects have been surging over the last few years. More than 1.6 million homes were built last year alone with hundreds of thousands of apartment buildings and complexes also being constructed. At the same time, commercial and industrial construction projects have been reaching record highs lately. As the need for new homes and businesses continues to grow, new construction projects will follow suit.

Numerous elements go into the construction process. Those include a range of materials and a long list of structural components, such as walls, floors, roofing, beams, columns, plumbing parts, and electrical wiring to name a few. Each one does its part to foster the stability, appearance, and functionality of the building it goes into. Additionally, metal purlins are essential in building. What are these components, though, and what roles do they play in roofing and construction? Read on to learn more about purlins and why they’re important.

What Are Purlins?

First let’s take a closer look at purlins and what they’re used for. They’re structural components, generally made of steel or other metals, used in roofing. They’re long, horizontal beams that run the length of a building to support the roofing materials. They aid in transferring the weight of the roof to other beams and the walls. At the same time, they prevent too much of that weight from resting on the walls and other structural components.

Two main types of purlins are used in construction: C-purlins and Z-purlins. As the names indicates, they’re essentially shaped like Cs or Zs. C-purlins can be used in both commercial and residential buildings. They provide added strength and stability, and they’re easier to attach to the panels of the roof. Z-purlins are more difficult to attach, but they’re stronger than C-purlins. As such, they offer more load-bearing capacity.

Other types of purlins are also available. Sleeved purlins may be used for larger roofs and those that require greater-than-average load-bearing capabilities. Top-hat purlins, as you might imagine, have a hat-like structure. They, too, provide added strength. Rectangular hollow section, or RHS, purlins are used in situations where other options may not provide enough strength.

What Are Metal Purlins Made of?

Purlins are generally made of aluminum or galvanized steel. While aluminum is lighter and more resistant to corrosion than steel, it’s not quite as strong. Steel is stronger but not as resistant to the elements. Still, galvanized steel has a protective zinc coating that helps it to withstand moisture and other hazards more effectively. Other types of steel can be coated with red oxide primer to give them greater corrosion resistance.

For the most part, aluminum purlins are generally used in smaller buildings and those that don’t require a great deal of roof strength. On the other hand, steel purlins are used for larger buildings and those in which added roof strength is essential. Those may include warehouses and factories to name a few possibilities.

Exploring the Roles of Purlins in Roofing and Construction

Purlins play several roles in roofing and construction. Their main purpose is to support the weight of a roof. They’re placed horizontally across the trusses where they help hold the roof in place. At the same time, they distribute the weight across the rest of the components around them. They basically give the roof a solid frame to rest on. That’s only one of their functions, though.

Providing Stability

Metal purlins also provide added stability. By supporting the roof, they prevent it from sagging, warping, or caving in under heavy loads. Their placement ensures that the roof can withstand weight from not only the roofing materials themselves but also outside forces like snow and wind. That, in turn, contributes to the safety and longevity of a roof.

Weight Distribution

As mentioned, purlins prevent too much of the weight of a roof from falling on walls and other construction components. They distribute that weight evenly across the rest of the support structure. That applies to water, accumulated snow, and other factors that may add weight to a roof as well. That further ensures a roof can last a long time even under fairly extreme pressure.

Aiding in Roof Installation

Another role metal purlins play in construction is aiding in the roof installation process. They give the other structural elements something to attach to and rest securely against. They also make it possible to install the roof deck and outer roofing materials, like shingles, tiles, shakes, or metal sheets. Without purlins in place, it would be all but impossible to affix those components securely. Furthermore, purlins create a space between the roof and the internal structural components. That can improve airflow and help with internal temperature control.

Improving Cost-Effectiveness

On top of the other roles mentioned here, purlins improve cost-effectiveness in construction. They’re lightweight, and they require less material than other support beams, like those made of wood. Since they’re made of metals, like aluminum and galvanized steel, they’re resistant to decay, rust, and insects. That helps them to last longer and reduces the need for ongoing maintenance. Unlike wood support beams, they won’t succumb to the elements, and they don’t need to be replaced very often.

Giving Buildings Strength and Stability

A long list of components and structural elements are essential in construction. Each one plays a key role in a building’s strength, longevity, aesthetic appeal, and other factors. Metal purlins are important pieces of the puzzle. They’re available in different forms to meet different needs. Each one provides its own level of strength, stability, and weight distribution. Metal purlins likewise contribute to a building’s durability and can provide added cost-effectiveness.

All that being said, it’s important to choose the right types of purlins based on the building being constructed, its location, the size of its roof, and several other factors. Installing purlins and other roof components properly is also crucial. Otherwise, they may not serve their purposes as well as they should. With those aspects in place, purlins can help a building to last longer and hold up to extreme weather along with many other benefits.