Roofing a Structure
Everything you need to build a strong, weather-resistant roof in Andaman
Browse All Roofing Materials →Roofing is one of the most critical aspects of any construction project in the Andaman & Nicobar Islands. With the region's high humidity, heavy monsoons, and cyclone-prone climate, selecting the right materials is essential for longevity. At Saran Traders, we stock a complete range of roofing materials — from color-coated sheets and corrugated variants to Structural Channels, Angles and Pipes used as purlins — so you can build with confidence.
Materials You Will Need
Tap any material to view products, specs & current prices
Step-by-Step Guide
How to approach your roofing a structure project
Calculate Roof Area & Pitch
Measure the total plan area of the roof and decide the slope angle. In Andaman, a minimum pitch of 15 degrees is recommended to ensure proper water runoff during heavy monsoons.
Select Sheet Type & Gauge
Choose between color-coated corrugated sheets for aesthetics or GI corrugated sheets for budget roofing. For coastal zones, opt for pre-painted galvanized sheets with a minimum 70 GSM zinc coating for corrosion resistance.
Build the Structural Frame
Erect your structural frame using Angles, Channels, GI Pipes or MS Pipes for columns and rafters. In Andaman's cyclone zone, ensure all connections are bolted and welded, not just fastened with wire.
Install Purlins
Fix purlins (horizontal members) across the rafters using GI Pipes or MS Pipes, Angles or Channels. Standard purlin spacing is 1.2m to 1.5m center-to-center, depending on sheet length and load.
Fix Roofing Sheets
Lay sheets from the bottom upward with a minimum 150mm overlap at side laps and 200mm at end laps. Use self-drilling screws with EPDM rubber washers at each purlin crossing. Typical density: 8 to 12 screws per sqm.
Seal Ridges & Joints
Fit ridge caps at the apex and seal all end laps with non-hardening sealant tape. Ensure gutters and downpipes are properly connected to prevent water damage to the structure.
Frequently Asked Questions
Expert answers to common questions about roofing a structure
QWhat gauge roofing sheet is best for Andaman's climate?›
For Andaman, we recommend a minimum 0.50mm (28 gauge) color-coated sheet for residential use. Always choose sheets with a minimum 70 GSM zinc+aluminium coating to resist the salt-laden coastal air.
QWhat is the difference between color-coated sheet and GI corrugated sheet?›
Color-coated (pre-painted) sheets have a aluminium+zinc (AZ) coating along with polymer coating over the AZ steel, providing superior corrosion resistance, aesthetics, and UV protection — ideal for roofs exposed to direct weather. GI corrugated (GC) sheets are uncoated galvanized steel, more economical, and commonly used for cladding, partitions, or secondary structures.
QHow many self-drilling screws are needed per square meter?›
The standard recommendation is 8 to 12 screws per square meter of roofing, depending on wind zone and sheet width. For Andaman (cyclone zone), use 10 to 14 screws per sqm — especially along eaves and ridges which experience the highest uplift forces.
QCan I use GI pipes as purlins?›
Yes. GI round pipes (typically 1.5 inch or 2 inch diameter, medium duty) are widely used as purlins for light steel roofs. They are cost-effective and readily available. For heavier structures, GI channels or MS angles provide greater section modulus and better load capacity.
QHow long do color-coated sheets last in Andaman?›
A quality pre-painted galvanized sheet with proper installation and maintenance typically lasts 10 to 20 years in Andaman's coastal climate. The key factors are zinc coating weight (minimum 70 GSM), paint quality (PVDF coatings last longer than polyester), and annual cleaning to remove salt deposits.
QWhere can I buy roofing sheets in Port Blair, Andaman?›
Saran Traders at Pathergudda, Bhathu Basti, Sri Vijaya Puram, Port Blair stocks a full range of roofing sheets and trusses material. We supply to contractors, builders, and homeowners across the Andaman and Nicobar Islands. Contact us at +91 99320 83698 or WhatsApp for availability and pricing.
QHow many roofing sheets do I need for a 50 sqmtr shed?›
For a 50 sqmtr shed with a simple pitched or flat roof, you will need approximately 16-17 standard color sheets (10ft × 3.2ft size) accounting for overlaps and edge wastage. You will also need self-drilling screws, GI angles for purlins, and MS channels or angles for the structural frame. Saran Traders can provide a complete material list — call +91 99320 83698 with your shed dimensions.
Ready to Start Your Project?
Browse our full catalog of roofing a structure materials with current prices. Questions? Our team in Port Blair is here to help.