Purlins Meaning: Types, Sizes, Uses, and Cost Explained

Purlins are a crucial component in the construction of roofs, particularly in metal roofing systems. They are horizontal beams that span between rafters, providing additional support to the roofing material.

Purlins come in various types, including solid purlins, hollow purlins, and corrugated purlins. Each type has its own unique characteristics and uses.

Solid purlins are the most common type and are made from solid steel or wood, providing excellent strength and durability. They are often used in commercial and industrial buildings.

Hollow purlins, on the other hand, are made from steel tubes and are lighter in weight, making them ideal for residential buildings.

A purlin is a lightweight, horizontal beam or bar used for structural support in roofing, particularly in commercial, residential, and industrial metal buildings.

Metal purlins increase a building's resistance to heavy winds and support the weight of the roof decking.

Purlins are a critical element to the structure of roofing, and there are different types of metal purlins characterized by their shapes.

Z purlins, for example, are horizontal beams that form the roof and wall joists of a building shell structure, resembling the letter Z and providing strength through overlapping joints.

C purlins and Z purlins are two types of metal purlins used in steel building purlin roofs, with Z purlins offering an advantage in terms of strength and studier design.

A purlin roof is a roofing type that uses metal purlins to support the roof's deck weight, creating a horizontal frame for complete support of the roof decking.

Metal purlins make a purlin roof more rigid and sturdier, allowing for the creation of wider buildings with mid-span support.

Using purlins can offer several benefits in construction and building projects. One of the main advantages is that they allow for longer spans, which can be a game-changer for large or open spaces.

Purlins are also incredibly durable, which means they can withstand the elements and last for a long time. This is especially important for outdoor structures or buildings in areas prone to harsh weather conditions.

One of the most significant advantages of using purlins is that they require no side drilling or cutting, which can save time and effort during installation. This is a huge plus for builders and contractors who value efficiency.

Galvanized Z purlins, in particular, offer superior strength, making them a top choice for heavy-duty applications. This type of purlin is also versatile and can be overlapped, which allows for greater flexibility during construction.

Here are some key benefits of using purlins:

Purlin sizes can vary, but they're typically between 4” and 12” wide, with a flange width of 1-½” to 4”.

Metal purlins are available in 12 gauge, 14 gauge, and 16 gauge.

Purlins can be custom-made to fit specific project requirements, including varying lengths and thicknesses.

Bansal C section purlins are available in a wide range of thicknesses, up to 3.2 mm.

Bansal SIGMA section purlins also offer a wide range of thicknesses, up to 3.2 mm.

Purlins can be manufactured to be un-drilled or with pre-drilled holes of various diameters, including oval and round shapes.

Web height for Bansal purlins is available up to 300 mm.

Purlins are in two main types: C purlins and Z purlins.

C shaped purlins, also known as SIGMA purlins, have special ribs that give them good structural properties, making them a popular choice for building shells.

SIGMA purlins are versatile and can be used to support beams for flooring, in addition to being suitable for walls and floor joists.

Steel purlins are a popular choice for building projects due to their lightweight and stable nature.

They are made of cold-formed material, which is thin enough to get through screws, making them easier to install.

Steel purlins are also resistant to extreme temperature changes, expanding and contracting moderately.

Some steel purlins have a zinc coating of different GSM for added durability in harsh weather conditions.

Steel purlins can be used in place of conventional wood purlins, offering a cost-effective and low-maintenance option.

They provide additional support between the spans of individual framing bays, increasing the resistance of the system to excessive rainfall.

Steel and Stud offers quality purlins derived from quality steel, using advanced technology to ensure precise measurements and accurate cutting.

Their consultation services are available until the project is complete, ensuring a smooth installation process.

Steel and Stud uses C-shaped SIGMA purlins, which have good structural properties and can be used to support beams required for flooring.

These purlins can also be used for door mounting, roof clipping, window trimming, parapet rails, and side rails.

Z purlins, also called Zee Purlins, are horizontal beams that form the roof and wall joists of a building shell structure, resembling the letter Z.

The shape of the z purlin allows for overlapping joints, making it stronger and sturdier than C purlins.

C purlins, formed in the shape of the C alphabet, are primarily used to support walls and floors.

Both C purlins and z purlins can be used in single spans, with similar extensions on their ends.

C shaped SIGMA purlins have special ribs, or bends in the web, which give them good structural properties and make them superior to the other two varieties of purlins.

These types of purlins are built to shape a building shell structure’s walls and floor joists, making them suitable for supporting the beams required for flooring.

C purlins and SIGMA purlins can also be used with door mounting, roof clipping, window trimming, parapet rails, and side rails.

Metal purlins are a crucial part of a roof's stability, providing an extra level of protection. They come in different types, including C Purlins and Z Purlins.

Metal purlins are available in various gauges, such as 12 ga, 14 ga, and 16 ga, and sizes ranging from 4” to 12”. You can choose from a red oxide or galvanized finish.

The correct spacing of purlins is essential for a stable roof. Installing purlins in a horizontal way below the metal roofing provides added support to the metal roof.

Purlins are installed above the roof rafters with a vapor barrier installed at the top. They are typically 2 feet by 4 feet in dimension and are installed similarly to metal roofs.

Here are the available options for metal purlins:

You can also use purlin cleats, which come in single and double varieties. Single cleats are commonly used in Z shapes, while double cleats are used for unlapped purlins or in areas with high reaction loads.

Installing purlins is a crucial step in creating a sturdy and rigid roof. Purlins are installed in a horizontal way below the metal roofing, above the roof rafters with a vapor barrier at the top.

They're usually installed in dimensions of 2 feet by 4 feet, and their installation is similar to that of the metal roofs. This provides added support to the metal roof as well as a surface for nailing the drip edge and the end panels.

To ensure a strong connection, it's recommended to overlap the ends of your purlins. Overlapping the ends creates a stronger connection than butting the ends together. In fact, overlapping the ends 12 inches past the truss and screwing them together is the recommended method.

Here's a quick rundown of what to do and what not to do when it comes to overlapping purlin ends:

Purlin sections assume the roof slope, and the spacing of the purlin must be carefully calculated to follow the nodal pattern for truss support. This is crucial for ensuring the stability of the roof.

The type of purlin used can impact the design. Z purlins, for example, have a stronger overlap joint compared to C purlins. This makes them a popular choice for large-scale structures.

Purlin laps are recommended at a length of 15% of the span. This helps to provide structural continuity and prevent failures. If there are unequal lengths of the span, each purlin should have 7.5% of the adjacent span instead.

Purlin laps that are less than 10% may not effectively provide structural continuity and may suffer from failures. It's essential to ensure that the purlin laps are sufficient to support the roof.

Here are some key points to consider when designing purlins:

Overlapping the ends of purlins creates a stronger connection than butting them together. This is especially important for longer spans, where the risk of failure is higher.

Purlins are a highly common architectural material used efficiently to support roof deck or sheathing. They are one of the many construction materials available on the market.

Purlins are considered reliable building materials because they help buildings last longer effectively. This is due to their ability to support roof deck or sheathing, making them a crucial component in construction.

Purlins are used in various construction projects, including factories and other facilities.

Metal purlins come in different gauges and sizes, which affect their pricing. The price range for 14 Gauge, Galvanized purlins is $2.00- $3.00 Per linear Ft.

For a 4” X 2” purlin, the price is $2.00- $3.00 Per linear Ft. This is the same price range for 14 Gauge, Red Oxide purlins of the same size.

A 6” X 2” purlin is priced at $3.00- $4.00 Per linear Ft. in Galvanized, while the same size in Red Oxide costs $2.50- $3.00 Per linear Ft.

The price for a 10” X 2.5” purlin is $4.50- $5.50 Per linear Ft. in Galvanized, and $4.00- $5.00 Per linear Ft. in Red Oxide.

Here's a summary of the purlin pricing for different sizes and gauges:

Purlins are considered reliable building materials due to their ability to efficiently support roof deck or sheathing.

Purlins are one of the many construction materials available on the marketplace that can be used to help and support roof deck or sheathing.

A variety of construction materials are available, making it easy to find the right materials for a project.

Purlins are highly common architectural materials that can be used to help and support roof deck or sheathing.

Effective use of purlins can help a building last longer.

Using the right materials, like purlins, is crucial for a building to be reliable and long-lasting.

Red oxide purlins are often used in construction because they're more affordable, saving you 25% to 35% compared to galvanized purlins.

However, galvanized purlins offer better corrosion resistance, making them a better choice for jobs near the ocean.

Red oxide purlins can be painted, which is a big advantage, but they'll still rust quickly without a finished coat of paint.

Galvanized purlins, on the other hand, can't be painted as easily.

Here's a comparison of the two:

Galvanized purlins are a better choice for harsh environments, but they're also more expensive and prone to white rust when exposed to moisture.