The term purlin is used to describe horizontal beams that offer structural support in buildings. Commonly, purlins have a highly crucial role in the roof structure of buildings. Purlins are supported by rafters or building walls when they are laid horizontally. The roof deck can be laid comfortably and safely over the purlins using this support. By “roof deck”, here, we mean the metal sheets used to create the surface of the roof. When using roof purlins and battens, the purlins are applied directly to the roof rafters that run perpendicularly between them. In contrast, the battens are nailed to the roof sheathing or applied over the existing roof for installing a new roof.
Some roofs, like the 5V crimp metal, were once installed directly to the purlins. However, the building codes need roof sheathing along with a layer of roofing felt or other approved water-resistant surface over the sheathing before installing the roof covering. The air gap that the battens create between the sheathing and the roof can be helpful as a thermal barrier. The rigid insulation can be placed in the space between the battens. Some roof purlin and roof batten installations go a step further and use battens running up the roof. A second layer of battens runs perpendicular over them to offer ventilation between the roof material and sheathing at the ridge.
Another type of purlin is used for the additional structural support under the roof rafters with an older style of roof framing that predates manufactured roof trusses.
Purlins create a horizontal frame that supports the complete weight of the roof deck, regardless of which materials are used. More importantly, purlins also improve the rigidity and breadth of the buildings by acting as the mid-span support while offering a nailing surface for the end panels and drip edges.
C-Purlins are used over the walls, rafters, floor joists and studs for the walls. They get the name from the square C shape.
This type of purlins is used when the joints must be overlapped. It is stronger and much more reliable than the C-purlin. Therefore, it’s used for larger-scale structures like commercial or industrial buildings. This type also gets its name from the Z-type appearance.
When it is about roof purlins and battens, this is a unique purlin that is used in roofs where the support structure is visible after the project is complete. They are available in hollow and rectangular tubes instead of steel bars.
Apart from the C, Z, and RHS purlins, these structural support tools are categorized by the material that they are made up of. Most people these days opt for galvanized steel roof purlins because of their durability, cost, flexibility in shape, and all-around structural strength.
Galvanized steel purlins are the replacements for wood purlins. Why? They are accurate, stable, and light in weight, but they can also contract and expand suitably in extreme temperatures. This is why they are a better option for all climates. Galvanized steel purlins are formed of cold-formed steel. This steel type is thin enough for drilling screws through. It is made by rolling multiple sheets together into the desired shape. A benefit of this type of material is the cost. This is far less than hot-rolled steel.
When it is about roof purlins and battens, there is a complicated manufacturing process for steel purlins. Steel roof purlins are made up of hot-dipped steel that is galvanized and coated (like any other steel product in the construction industry). The reason for this coating is to protect the steel from corrosion.
If you plan to buy roof purlins and battens, buying in bulk or by unit is better. Ezi Batten is the best place to purchase roof purlins and battens. We are the experts in all things roofs and stock up a comprehensive range of purlins and other essential roofing materials and accessories.