How to Install Roof Shingles on a Metal Structure with Purlins and Cement Fibre Board Underlayment?

Imran Ahmed

Roof shingles are becoming increasingly popular in India for residential homes, resorts, and even commercial structures due to their durability and aesthetic appeal. Installing roof shingles on a metal structure with purlins and an underlayment requires precision and a clear understanding of the materials. Whether you’re roofing a resort or aiming for a European-style roof, this step-by-step guide will walk you through the process, ensuring a strong, long-lasting, and waterproof roof.Materials Required:

Roof shingles (variety based on your design preference)
16mm Cement Fibre Boards
Purlins spaced every 600mm
PU Sealant (55 Grade)
Shalimar HDSA Tar Felt (Waterproofing membrane)
15mm Self-Drilling Screws
Flashings and Ridge Caps (for finishing)

Step-by-Step Installation Process:

1. Prepare the Metal Structure:

Begin by ensuring that your metal structure is solid and secure, with purlins spaced at every 600mm. The purlins act as support for the Cement Fibre Boards and the roof shingles.
Make sure the purlins are clean and free of rust or debris. A strong and well-prepared frame is essential for proper shingle installation.

2. Install the Cement Fibre Boards as Underlayment:

Lay 16mm Cement Fibre Boards across the purlins, ensuring that they fit securely. Cement Fibre Boards provide a solid base and help to create a smooth surface for the shingles.
Leave a small gap between each board to allow for thermal expansion and contraction.
Seal all the joints between the Cement Fibre Boards using PU Sealant (55 Grade). This step is crucial to prevent moisture from penetrating the gaps and compromising the structure’s integrity. PU Sealant offers flexibility and a strong bond that can withstand temperature changes and weather exposure.

3. Apply the Waterproofing Layer:

To further protect the structure from water infiltration, cover the surface of the Cement Fibre Boards with Shalimar HDSA Tar Felt. This material is widely used in roofing solutions across India due to its impermeability and long-lasting waterproofing properties.
Roll out the Shalimar HDSA Tar Felt across the boards and fasten it using compatible roofing nails or adhesives, ensuring the felt is evenly distributed. Overlap the edges by a few inches to create a continuous, impermeable barrier.

4. Start Installing Roof Shingles from the Eave End:

Begin installing the roof shingles from the eave end (the lower edge of the roof). Starting from the eave ensures that each layer overlaps the one below, creating a shingle effect that helps shed water.
Align the first row of shingles carefully and secure them to the structure using 15mm Self-Drilling Screws. The screws should be placed at the top edge of the shingles, ensuring they are fastened tightly to the purlins through the cement boards.
Continue installing the shingles upwards, ensuring that each subsequent row overlaps the one below. This overlapping pattern is essential for waterproofing and longevity.

5. Install Flashing and Ridge Caps:

At the edges of the roof and any joints, install flashing to prevent water from seeping into vulnerable areas. Flashing is essential for sealing valleys, ridges, and other critical points where water can accumulate.
Finish the top of the roof with ridge caps to protect the peak from water ingress while providing a neat, professional appearance. Secure the ridge caps using the same self-drilling screws for consistency.

6. Inspect the Roof for Quality and Waterproofing:

Once the shingles are in place, perform a thorough inspection to ensure there are no gaps, loose shingles, or exposed screws. The roof should be tightly sealed at every point.
Test the waterproofing by spraying water across the surface, simulating heavy rainfall. Ensure that water runs off smoothly without any pooling or leaks.

Why Choose Roof Shingles for Your Project?

Roof shingles, especially when installed on a solid underlayment like Cement Fibre Boards, provide excellent durability and weather resistance. They are perfect for a wide range of roofing projects, from resort roofs to residential homes, and offer a European roof aesthetic that many prefer for its elegance and functionality. Roof shingles are versatile, lightweight, and available in many styles and colors. When combined with waterproofing layers like Shalimar HDSA Tar Felt, they ensure long-lasting protection from the monsoon rains and intense heat often encountered in the Indian climate.

Final Thoughts:

Installing roof shingles on a metal structure with purlins and Cement Fibre Board underlayment provides a robust and waterproof roofing solution. With the right preparation, waterproofing, and installation techniques, you can achieve a long-lasting and visually appealing roof for your next Indian roofing project. This method ensures that the roof withstands the elements, from the heavy rains of the monsoon season to the high temperatures of summer, all while providing an energy-efficient and aesthetically pleasing finish. For those looking for premium roofing solutions that combine durability, style, and weather resistance, roof shingles offer the perfect balance. Whether you’re working on a residential home, a commercial building, or a roofing resort project, these materials deliver the performance and beauty you need.