What are corrugated roof sheets? Benefits, types, installation process and more

There has been a significant shift in the Indian roofing industry from conventional options like tiles to more value-for-money steel roofing solutions. The growth in industrial applications is a major cause for the same. This shift has created a huge demand for different kinds of steel sheets for protecting the roof in domestic, commercial, and industrial institutions. One of the best options that is available in the market is corrugated roof sheets – distinguished by its unique wavy design and its versatile uses.

What is a corrugated roof sheet?

Corrugated roof sheets are popular roofing solutions and can be distinguished by the repetitive folds on their surface. The unique shape of the sheets offers years of reliable utility and greater strength. They can be made from different metals – steel, tin etc. that gives them its robustness.

Corrugated roof sheets manufacturing involves a process where the metal is rolled into a wave like pattern for structural strength and ability to resist weather and mechanical impacts. The corrugated design on the sheets with ridges and grooves make them stronger and durable.

As a builder, when selecting a corrugated roof sheet check its types, size and specifications.

• Galvanised steel sheet usually forms the base for most types of corrugated sheets. It is usually coated by polyester paint or protected by PVC Plastisol and offers excellent resistance to corrosion and harsh weather.
• Polyester painted sheets are usually used in agricultural buildings for its medium-length lifespan and economic efficiency.
• PVC Plastisol coated corrugated sheets comprise steel sheets treated with primer paint and PVC rolled on their surface. These roofing sheets are very durable lasting for around 25-30 years.

Corrugated sheet thickness:

These roofing sheets are available in 3 gauges – 0.42, 0.48 and 0.60. While 0.42BMT is used mainly for domestic roofing, the 0.48BMT is more popular for commercial applications. Out of the three 0.60BMT is the heaviest and strongest of all.

Installation:

Also, ensure that during corrugated roofing sheet installation there’s proper alignment and secure fastening to prevent leaks. Regular maintenance, removing rust and debris, is also recommended for its long life span, cost-effectiveness, and enhanced architectural appeal.

Corrugated metal sheet prices:

In India, regular corrugated roof sheeting prices is in the range of ₹250/square meter to ₹500/square meter.

What are the benefits of corrugated sheets?

Corrugated steel roofing sheets are now a popular option for many businesses and private homeowners. The five major benefits of using corrugated metal roof sheets and why they make a better option are given below:

• Prevents water build up: Due to the unique shape, corrugated roof sheets help water run downwards and keeps your roof top clear.
• Durable: A corrugated roof sheet that is made from metals like steel or aluminium lasts for years and needs very little maintenance apart from a coat of paint occasionally.
• Lightweight: Apart from being durable, these sheets are also lightweight making it easier to handle and install. It also does not increase the weight of the building structure.
• Withstand weather conditions: Equipped to survive all weather conditions, corrugated sheets provide a protective barrier to your establishments and never rusts.
• Rot resistant: Unlike most roofing material, corrugated metal roof sheets do not rot. Most metal sheets are also protected with a layer of chemicals to stop the formation of algae.

Also read: Corrugated metal pipe – Sizes, prices, manufacturing process

Why use corrugated roofing?

So why should you used corrugated metal roofing sheets? As we have seen in the previous section, these roofing sheets offer distinct advantages that makes them the preferred choice in industrial and residential construction projects.

• Durable and long lasting
• Corrosion resistant (metal specific) and robust to withstand extreme weather conditions (Also read: Steel corrosion)
• Lightweight and easy to install
• Cost-effective in the long run
• Reduces cooling costs in buildings

We’ve prepared a comparison between regular roofing sheets and corrugated metal roofing sheets for you to evaluate the benefits:

Feature	Regular metal roofing sheets	Corrugated metal roofing sheets
Structural integrity	Lesser strength	Higher strength and durability due to corrugation (ridges)
Aesthetic properties	Limited styling as these are regular sheets	Diverse style, design and finish available based on choice of metal
Weather resistance	Less resistant to harsh weather, atmospheric moisture, and other environmental hazards	More resistant to harsh weather conditions, especially resistance to corrosion, rust, heavy rains, and heating (cooling effect)

Also read: Stainless steel roofing sheets

What are the sizes of corrugated roof sheets?

Corrugated steel roofing sheets are one of the most popular roofing solutions and they come in various sizes that builders and business owners can secure based on their requirements. The flexibility in corrugated roof sheet sizes helps address different construction and architectural needs, balancing functionality with aesthetic appeal.

Corrugated steel roofing sheets sizes and application

Size type	Length (in meters)	Application
Small	1.8 m – 3.5 m	Small sheds, garages
Medium	4 m – 10.0 m	Residential house roofing, small factory workshops
Large	12.0 m – 20.0 m	Industrial warehouses, large sheds

*For reference only. Please check with your steel supplier for actual sizes and dimensions.

From small residential projects to industrial applications, it’s important to use corrugated roof sheet sizes accurately for efficient coverage and fewer seams.

In India, due to storage and transportation issues, most steel suppliers and distributors will stock corrugated roofing sheet sizes across 2 m, 2.1 m, 2.7 m, 3 m, 4 m, 5 m, 6 m and 8 m. For larger sheets or special sizes, check with the manufacturer.

Also read: Sheet bending machines – Understand how steel sheets are bent into different shapes and sizes

What are the types of corrugated roofing sheets?

Corrugated root sheets provide an environment-friendly option to businesses to use as roofing solutions. There are several types of corrugated sheets that you can choose from. The four types are highlighted below:

• Galvanised steel sheet: A carbon steel sheet coated with zinc, these corrugated sheets can either be used bare or painted.
• Polyester painted sheets: Mostly used for agricultural structures, these sheets need to be maintained every five or ten years.
• PVC Plastisol: A steel sheet that is treated with a steel primer paint and rolled in PVC, this type of sheets is used for its durability and is expected to last up to 30 years.
• Bitumen: These corrugated roofing sheets are made from bitumen. It is waterproof, long-lasting, and highly durable.

What is the best type of corrugated roofing?

Corrugated metal roofing sheets can be manufactured from different materials/metals. Popularly used materials for corrugated roof sheets are: bitumen, PVC, polycarbonate and metals such as tin, aluminium, and steel (galvanised and stainless steel).

Popular corrugated metal roofing sheets example and applications:

Metal type	Benefits/Features	Applications
Corrugated steel roofing sheets	Affordable, strong, and easily available	Industrial and storage facilities
Corrugated galvanised steel roofing sheets	Durable, rust-resistant, slightly expensive	Warehouses, industrial buildings
Corrugated stainless steel roofing sheets	Expensive, corrosion-resistant, long-lasting, aesthetically appealing	High end buildings, commercial structures
Corrugated tin roofing sheets	Moderately resistant, lightweight, economical	Temporary setups, small structures
Corrugated aluminium roofing sheets	Lightweight, highly corrosion resistant	Residential structures/houses, coastal and marine environment

As can be understood, the best corrugated roofing sheet type depends on the structure being built and the environment it is being constructed in. Galvanised steel corrugated roof sheets however stands out in India due to its strength, durability, cost-effectiveness and rust resistant properties.

Also read: Tips to reduce steel corrosion

How to install corrugated roofing sheets?

Installing a corrugated roof sheet is a straightforward process. Let’s take a look at it with an example. You can use corrugated steel roofing sheets or corrugated tin roofing sheets or any other, but the steps remain the same.

Steps to install corrugated roofing sheets:

Imagine installing a corrugated steel roofing sheet on a residential garage in a city (e.g., Chennai). The structure will be exposed to heavy rains and harsh weather (heat) and requires a robust, waterproof, and cooling roofing solution.

Step 1:

Prepare the roof frame by clearing any debris or old roofing material. Ensure it is sturdy and clean.

Step 2:

Measure the roof and cut the sheets to size. For instance, if the roof is 12×8 feet, you will need approximately 6 steel roof sheets, each measuring 4 feet in length.

Step 3:

Begin laying the sheets from the bottom left corner of the roof. Ensure each sheet overlaps the previous one by approximately 2-3 inches.

Step 4:

Secure the sheets using steel nuts and bolts, screws and nails. Ensure the sheets are strongly attached to the rafters. Maintain small spaces between the fasteners/screws, roughly 4 to 6 inches.

Step 5:

Seal any gaps between the overlapping sheets by applying a high-grade sealant to prevent leaks.

Step 6:

Complete the installation by fitting a ridge cap across the top of the roof. This will give it complete coverage, enhance its waterproofing capabilities and structural integrity.

How much should corrugated roofing sheets overlap?

Proper overlapping of the corrugated metal roofing sheets is important to ensure there is no water leaking and for its longevity. Typically, an overlap of at least 2 corrugations between sheets is recommended.

We’ve compared different scenarios to explain the guidelines:

• Residential garages: For a standard garage with a flat slope roof, basic overlap of 2 corrugations is sufficient to ensure there is no leakage through the joints
• Industrial warehouses: Since the roof span wider areas in large structures, an extra coverage overlap of 15 to 24 inches is recommended, to withstand large volumes of water
• Agricultural buildings: Here too, a basic 2 inch overlap will work, especially for small barns and agricultural settings, though it is recommended to add an additional layer of sealant for waterproofing

How to cut corrugated polycarbonate roofing sheets?

To cut corrugated polycarbonate roofing sheets you must take care to be precise in measurements to keep the installation safe. Follow the steps below:

• Measure the dimensions precisely and make markings on the sheet for accurate cutting
• Use suitable tools for cutting polycarbonate roofs such as a circular saw
• Clamp the sheet to a stable structure during cutting to prevent dislocation and movement
• Cut along the marking slowly and continuously to avoid chipping

As a safety measure, always ensure to wear proper gear when cutting sheets, check the sharpness of the blade to avoid jagged edges, and use support equipment to keep the sheets stable.

Also read: Cladding sheets – Learn how wall cladding sheets are used

How to lay corrugated roof sheets?

We saw during the corrugated steel roof sheet installation process why it is important to lay the sheets correctly. Here are the steps to lay corrugated roof sheets:

• Begin installing the sheets from the bottom left side
• Ensure to overlap sheets by at least 2 corrugations to prevent leaks and seepage
• Use steel fasteners and screws to securely fasten the sheet joints to the rafters
• Apply sealant or rubber washers to provide further protection

Before you begin to lay the corrugated metal roofing sheets, ensure that you have the sheets cut precisely as per required dimensions, wear safety gloves, glasses and other gears, and use walk boards to walk.

How to fit corrugated roof sheets?

To ensure structural safety and durability, it is essential that you fit the corrugated roof sheets correctly. Here are the steps to help you with it:

• Begin by positioning the first sheet correctly at the bottom end of the roof
• Place the next sheet over it (ensure at least 2 corrugations between them)
• Use screws and nuts to securely fasten the sheets at the joints
• Apply sealant if required to provide additional waterproofing based on the environmental conditions

During the fitting stage ensure the sheets are aligned straight (use chalk lines if required), wear the required safety gear, and do not over tighten at the joints as it may warp and damage the sheets.

How to start a business for corrugated roof sheets

The corrugated roof sheet sector is a booming industry with an ever-present demand from commercial, industrial and agricultural sector consumers. While this business requires a heavy investment, it has minimal maintenance cost and a profit margin between 60%-80% annually.

If you’re interested in learning more about procurement of corrugated roof sheet, or want to buy corrugated roof sheets and other types of steel sheet, you can reach out to us at Tata nexarc. We have partnered with verified sellers and help you to buy quality steel products at the best prices, effortlessly. Explore today.