2026.09.02
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Choosing the right roofing screw involves more than finding the correct length or matching the screw-head colour. Buyers must consider the roofing profile, supporting material, corrosion-resistant coating, sealing washer and surrounding environment.
This is especially important when selecting COLORBOND® Roofing Screws. Two screws may look almost identical but have different drill points, coating classes or substrate limitations. Choosing an unsuitable fastener can result in installation failure, water leakage or premature corrosion.
This article explains how to compare COLORBOND® Roofing Screws in three practical steps:
COLORBOND® Roofing Screws generally refers to fasteners selected for installing roofing or cladding manufactured from COLORBOND® pre-painted steel.
These fasteners commonly feature a corrosion-resistant coating, hexagonal head and sealing washer. Painted heads are also available to coordinate with popular COLORBOND® steel colours.
However, colour matching alone does not confirm whether a screw is suitable. Buyers must still check its complete specification, including:
A colour-matched screw with insufficient corrosion resistance may deteriorate before the surrounding roof sheet. For this reason, the fastener coating and application rating should be considered before selecting the head colour.
COLORBOND® Roofing Screws may be used to secure compatible metal roofing or wall cladding to timber battens, steel purlins, top hats and other supporting structures.
Common applications include:
The correct screw depends on both the roofing profile and the material underneath the sheet.
A Type 17 roofing screw is commonly used when fixing metal roofing into timber. Its pointed tip helps the screw start and cut into the timber substrate.
When the support is steel, a compatible self-drilling roofing screw is usually required. Its drill point must be capable of penetrating the actual thickness and grade of the steel support.
Roof profile is another important consideration. Some profiles are fixed through the crest, while others use concealed clips or different fixing positions. Always follow the roofing manufacturer’s installation instructions rather than choosing fasteners by appearance alone.
Purpose-selected COLORBOND® Roofing Screws help create a compatible and weather-resistant fastening system. They secure the roof sheet while reducing the risk of moisture entering through the fixing hole.
Their main benefits include:
✦ Material compatibility: Appropriate fasteners help reduce premature corrosion and adverse reactions between different metals.
✦ Weather sealing: A correctly installed sealing washer helps prevent water from entering around the fixing hole.
✦ Colour coordination: Painted screw heads can complement COLORBOND® steel roofing and cladding.
✦ Efficient installation: Hexagonal heads can be installed using suitable roofing drivers.
✦ Substrate options: Different screws are available for timber battens and steel supports.
✦ Environmental protection: Different coating classes allow the fastener to be matched to the project’s exposure conditions.
The fastener should provide durability appropriate for the expected service life of the roofing system. Using a low-grade screw with a durable roof sheet may cause the fastener to fail first.
No. COLORBOND® Roofing Screws may have similar shapes and colours but differ substantially in performance and intended use.
A typical roofing screw may include:
Two screws with the same gauge, length and colour may have different coating classes. Their drill points may also be designed for different supporting materials.
One screw may be suitable for timber, while another may be designed for light-gauge steel. A separate product may be required for thicker steel purlins.
Therefore, paint colour should be the final matching step—not the first selection criterion.
A practical selection process involves checking the supporting material, corrosion class and sealing components.
Before choosing COLORBOND® Roofing Screws, identify the roofing sheet and its supporting structure.
Check the following:
For timber supports, choose a roofing screw designed specifically for timber, commonly featuring a Type 17 point.
For metal supports, select a self-drilling screw with a drilling capacity that covers the actual steel thickness. Do not use a screw intended for thin steel on a substantially thicker steel purlin. The drill point may overheat, become damaged or fail to penetrate the support correctly.
For concealed-fix roofing systems, visible roofing screws may not be used to secure the main sheet. These systems generally require manufacturer-specified clips and compatible fasteners.
Roofing screws are continuously exposed to moisture, condensation, pollutants, salt and temperature changes. The fastener’s corrosion resistance must therefore suit the roofing material and local environment.
The appropriate coating depends on factors such as:
A simplified comparison is shown below:
| Coating option | General application | Important consideration |
|---|---|---|
| Class 3 | Many general exterior roofing and cladding applications | Must still match the roofing product and local exposure conditions |
| Class 4 | More demanding exterior or marine-influenced environments | Often considered where greater corrosion resistance is required |
| Proprietary high-performance coating | Selected severe or highly corrosive applications | Confirm its tested performance, warranty and roofing compatibility |
| Stainless steel | Specialist roofing systems and selected severe environments | Stainless grade and compatibility with the roof sheet must be verified |
LYSAGHT® currently advises using fasteners complying with AS 3566 Class 3 or better for COLORBOND® steel applications. Its location-specific guidance lists Class 3 for many external applications more than 400 metres from the ocean or another severe influence, and Class 4 for certain severe marine exposures approximately 200 to 400 metres away. Local conditions and the selected roofing product may change these requirements.
Coating class should not be selected by price alone. Consider the expected roof life, accessibility and future cost of replacing corroded fasteners.
Where a screw penetrates a metal roof sheet, an appropriate sealing washer is generally required. EPDM sealing washers are commonly used to create a weather-resistant seal around the fixing hole.
The washer must sit evenly against the roof sheet. Installation pressure is important:
Use a depth-controlled screw gun or an appropriate torque setting. The washer should be compressed sufficiently to form a seal without being forced outward or damaged.
Class 3 fasteners may be suitable for many general exterior roofing and wall-cladding applications. However, Class 3 should be treated as a starting point rather than a universal answer.
A higher corrosion-resistance level may be necessary when the building is exposed to:
The roofing manufacturer, fastener supplier, building designer or engineer should confirm the final selection when exposure conditions are uncertain.
Class 4 fasteners should be considered when the roof is exposed to more demanding environmental conditions or when the roofing system specifically requires enhanced corrosion resistance.
They may be appropriate when:
Distance from the coast should not be the only deciding factor. Wind direction, building height, topography, nearby surf conditions and areas sheltered from rain can all influence corrosion risk.
There is no single screw size suitable for every COLORBOND® steel roof.
Common roofing fasteners include 12G and 14G screws in lengths such as 35, 45, 50 and 65 mm. However, the correct specification depends on:
When reading a screw specification such as 12-14 × 50:
Always use the size specified by the roof-profile supplier, building designer or project documentation.
Before ordering COLORBOND® Roofing Screws, confirm the following information:
Providing these details to the screw manufacturer or supplier can reduce selection errors and help ensure the fastener is suitable for the roofing system.
The right COLORBOND® Roofing Screws must match the roofing profile, supporting material and environmental exposure. Start by identifying whether the roof is fixed to timber or steel, then compare the corrosion class, drill-point capacity, screw length and sealing washer.
A colour-matched head provides a cleaner appearance, but it should only be selected after the technical requirements have been confirmed.
Need help selecting suitable COLORBOND® Roofing Screws for timber battens, steel purlins or coastal roofing applications? Contact us with your roof profile, support material and project location for product recommendations.