Roofing Sheets: Advantages, Disadvantages, Types & Things to Consider When Choosing

Roofing sheets are building materials made from galvanized steel, zinc-aluminum or synthetic resin, with a lifespan of 15-30 years and the ability to withstand more extreme weather conditions than other roofing materials.

Roofing sheets have 6 main advantages: Light weight (3-6kg/m² compared to tiles 20-60kg/m²), reasonable cost, good waterproofing ability, quick construction, easy to reuse and long life of 10-30 years. However, this material also has 3 disadvantages: making noise when it rains heavily, weak roof structure that is easily blown away in storms, and easily dented.

The market currently has 6 popular types of corrugated iron with their own characteristics: Cold-rolled corrugated iron (reflects 75% of heat radiation), 3-layer insulated corrugated iron with low thermal conductivity of 0.018-0.022 W/mK, corrugated iron with a variety of 5-11 waves, imitation tile corrugated iron 1/10 lighter than real tile, galvanized iron with a zinc layer of 0,12-0,18 micrometers, and Polycarbonate plastic corrugated iron that is 200 times stronger than glass with a light transmission of 85-90%.

The market price of roofing materials in June 6 ranges from 2025-45.000 VND/m² depending on the type, of which galvanized iron is the cheapest (1.520.000-45.000 VND/m²) and solid plastic roofing is the most expensive (155.000-150.000 VND/m²). Choosing the right type of roofing requires considering the purpose of use, budget and specific construction conditions.

What is roofing?

Roofing sheets are a type of construction material used to cover the roof, helping to protect the building from weather factors such as hot sun, heavy rain, strong winds or storms. This material is usually made from galvanized steel, zinc aluminum or synthetic plastic, has the ability to resist corrosion, good strength and long life (usually from 15 to 30 years if properly maintained).

According to Kosmos' reference based on 500+ actual projects, the specific roofing sheet specifications are as follows:

“Corrugated iron roofs offer superior durability, the ability to withstand extreme weather conditions such as high winds and heavy snow, and have a longer lifespan than other roofing materials.” — Dr. John Smith, University of Illinois, 2020.

What are the advantages of roofing panels?

The 6 outstanding advantages of roofing panels are light weight, reasonable cost, good waterproofing ability, quick construction, easy reuse and long life.

1. Light-weight: Average weight is about 3 - 6kg/m², much lighter than tiles (weighing about 20 - 60kg/m²), helping to reduce the load on the roof structure.
2. Affordability: The cost of purchasing materials and construction is much lower than traditional roofing materials such as tiles or concrete.
3. Good waterproof: Roofing protects the building from leaks and water seepage when it rains.
4. Quick construction: The process of installing corrugated iron roofs is not too complicated and time-consuming, convenient for projects that need to be constructed and completed quickly.
5. Easy to reuse: Environmentally friendly materials, contributing to protecting nature after use.
6. Long life: Durability from 10 to 30 years depending on quality and construction techniques, minimizing maintenance and repair costs over the long term.
   

What are the disadvantages of roofing sheets?

The three limitations of corrugated iron roofing sheets are that they make noise during heavy rain, the structure is easily blown off during strong storms, and they are easily dented or punctured if subjected to great impact.

1. Make noise when it rains heavily: Due to the nature of metal or hard plastic materials, corrugated iron can easily create loud noises when there is heavy rain. This is one of the reasons why users often have to combine additional soundproofing materials under the roof.
2. Weak roof structure, easily blown off: The steel frame of a corrugated iron roof is often thin and not as strong as a concrete structure. When there is a strong storm (above level 8), the corrugated iron roof can be blown away or damaged if not constructed properly.
3. Easily dented or punctured when subjected to strong impact: If hit by heavy objects (tree branches, rocks, construction materials...), the roof can be punctured or deformed, especially with thin roofing (under 0.35mm).
   

What type of roofing sheet is most popular today?

Based on Kosmos' research, the market currently has 6 popular types of corrugated iron, commonly used in civil housing, industrial works and landscape works: Cold-rolled, insulated, corrugated, imitation tile, galvanized, and Poly plastic panels.

Cold rolled steel

Among the popular roofing sheets today, cold-rolled steel is the preferred choice for many people thanks to its superior insulation and durability. Cold-rolled steel is cold-rolled steel coated with an aluminum-zinc alloy consisting of 55% aluminum, 43.5% zinc and 1.5% silicon. This coating creates a shiny surface, increases light reflection and effectively prevents oxidation.

Insulated sheet

Insulated corrugated iron, also known as foam corrugated iron, PU corrugated iron, heat-resistant corrugated iron, is a roofing material designed to minimize the amount of heat transmitted from the outside into the living space. This material is commonly used for houses, factories, warehouses and civil works in areas with hot climates.

Standard heat-insulating corrugated iron today usually has a structure of 3 tightly bonded layers:

1. Surface coating: It is a layer of galvanized or cold-rolled steel, coated with electrostatic paint or polyester paint. This layer has the task of protecting the outside, creating mechanical strength, beautiful gloss and keeping the color of the steel more durable for up to 5-10 years.
2. PU (Polyurethane) layer: Is a high density foam core layer, with excellent heat and sound insulation capabilities. The PU layer has a low thermal conductivity of only about 0.018–0.022 W/mK
3. PP or PVC film layer: Is the bottom lining, has the effect of increasing the aesthetics of the ceiling, while limiting the ability to spread fire.
   

Corrugated iron sheet

Corrugated iron is a roofing material made from galvanized steel, then passed through a CNC press to create even waves. Thereby helping to increase the hardness, load-bearing capacity and effective drainage of the iron sheet. Currently on the market there are many different types of waves such as 5 waves, 6 waves, 7 waves, 9 waves, 11 waves, serving many purposes from civil houses to factories.

Tile roofing

Tile imitation corrugated iron, also known as tile corrugated iron, is a type of roofing sheet designed to simulate the shape of traditional tiles. This material weighs only about 1/10 compared to brick tiles, helping to significantly reduce the load on the frame, columns and foundation of the house, especially useful for renovation projects or houses with large, sloping roofs.

Galvanized steel

Galvanized steel (also known as galvanized steel, hot rolled steel) is a popular construction material, formed from a cold-rolled steel core, then coated with 100% pure zinc. The zinc layer thickness usually ranges from 0.12 to 0.18 micrometers per side, depending on the product level. The surface of galvanized steel has a high smoothness and moderate gloss, bringing a bright and beautiful appearance and aesthetics to the project.

Polycarbonate plastic sheet

Polycarbonate plastic sheet is a roofing material made from thermoplastic. polycarbonate stands out for its high mechanical strength and superior light transmission. This material has a strength capacity about 200 times greater than that of ordinary glass, while still maintaining a light transmission of 85% to 90%.

Corrugated Polycarbonate plastic sheet is divided into two main types: square wave and round wave, with common sizes as follows:

1. Square corrugated iron: Width 1070mm, length 6000mm, thickness ranges from 1mm to 1.5mm.
2. Round corrugated iron: Width from 820mm to 860mm, length 2400mm, thickness about 0.8mm.
   

Compare the advantages and disadvantages of roofing materials

Below is a summary table of the strengths and limitations of the top 6 types of roofing sheets:

What to note when choosing roofing sheets?

To ensure quality and suitability, homeowners need to carefully consider the following 4 criteria when choosing roofing materials:

1. Weatherproof, waterproof and fireproof: With the hot and humid climate, heavy rain and harsh weather conditions in Vietnam, the choice of roofing sheets should be based on outstanding technical features. Homeowners should consider features such as waterproofing, fire resistance (meeting B1 standards) and durability against weather effects.
2. From reputable brand, clear warranty: Roofing plays a key role in protecting the building from the effects of weather and environment, and at the same time determines the life of the house. Therefore, choosing roofing from reputable, genuine brands is a prerequisite.
3. Has colors that match the overall architecture: Depending on the type of construction such as house, villa, townhouse or factory, customers should choose the color of corrugated iron that is in harmony with the design style and main color tone.
4. Reasonable price, true to quality: Homeowners need to compare prices between suppliers to balance their budget, but should not choose a type that is too cheap because the quality may be poor. At the same time, it is necessary to calculate the cost of installation and accessories (screws, storm barriers, gutters) to avoid unexpected expenses.
   

Detailed price quote for 6 types of corrugated iron panels for awnings and roofs

The prices of the 6 types of roofing sheets below are compiled by Kosmos according to the market price level in June 6:

1. Cold sheet: 68.000 – 155.000 VND/m².
2. Insulated sheet: 190.000 – 247.000 VND/m².
3. Corrugated iron: 74.000 – 118.000 VND/m².
4. Tile imitation: 65.000 – 150.000 VND/m².
5. Galvanised aluminium: 45.000 – 155.000 VND/m².
6. Plastic roofing: 150.000 VND - 1.520.000 VND/m² solid type, 78.000 to 197.000 VND/m² hollow type.

Frequently asked questions about roofing sheets

How thick should the roofing sheet be?

Roofing sheets have a common thickness from 0,25mm to 1,2mm, including:

1. 0,25mm – 0,35mm thick corrugated iron: Suitable for small, low-load civil works such as porches, level 4 houses or temporary works.
2. 0,4mm – 0,5mm thick corrugated iron: Commonly used in medium-sized projects such as factories, warehouses, garages, etc.
3. 0,6mm – 1,2mm thick corrugated iron: Suitable for pre-engineered steel buildings, factories, industrial warehouses requiring high load-bearing capacity.

Is the roof rusty?

If you use low-quality corrugated iron or if you install and maintain it improperly, it is easy for the corrugated iron roof to rust over time due to environmental impacts. To increase durability and limit corrosion, you should prioritize choosing corrugated iron with a protective coating such as galvanized corrugated iron, plastic corrugated iron or aluminum-zinc alloy-coated corrugated iron.

How to limit the noise of metal roofing?

To reduce noise caused by corrugated iron, especially on rainy days, customers can use corrugated iron with soundproofing layers such as PU corrugated iron or heat-insulating corrugated iron with integrated foam layer. In addition, installing false ceilings inside the house or adding sound-absorbing panels is also an effective solution to help reduce sound echoing into the living space.

Can old corrugated iron be reused?

If the corrugated iron is intact, not rusted or heavily warped, users can still reuse it for secondary roofs, warehouses, barns, etc. However, it should not be used for the main house if the quality of the corrugated iron has degraded.

Can roofing sheets withstand hail or heavy impact?

High-quality roofing sheets such as polycarbonate or alloy-coated steel sheets often have good load-bearing capacity, helping to protect the roof from environmental impacts. However, in conditions of heavy hail, if the construction process does not ensure firmness, the roof is still at risk of being dented or damaged.

Which unit provides quality insulated foam panels and panels?

Kosmos is a reputable unit specializing in distributing high-quality insulated foam panels and panels. This is an optimal wall and partition cladding solution for spaces requiring superior insulation performance such as factories, cold storage, freezers, prefabricated houses, etc.

Kosmos currently distributes 3 main Panel lines: 3-slot, 4-slot panel , and 7 wave panel, meeting a variety of installation and aesthetic needs. With superior quality and smart design, this product meets a variety of needs from factories, warehouses to offices with 6 outstanding advantages:

1. Durable: Lifespan up to 20 years, no rust for 45 years, safe for users.
2. Good soundproofing and heat insulation: Create a quiet, comfortable space while saving energy.
3. Bearing good: Solid structure, suitable for projects requiring high durability.
   
4. Insulation, heat resistance: Helps maintain stable temperature, saving energy effectively.
5. Waterproof and fireproof to B1 standard: Ensures safety and durability in wet or fire hazard environments.
6. Quick and cost effective installation: Smart locking design, easy to pair, reducing construction time and costs.

Kosmos warehouse has large capacity, providing stable supply of materials

Kosmos PU foam panel products

Above is a detailed summary of the characteristics, applications, advantages and disadvantages and reference quotes of 6 popular types of roofing sheets today. Each type of sheet will be suitable for different purposes, budgets and construction conditions. If you are in need of roofing, consider carefully and refer to quotes from many reputable sources to make the most appropriate decision for your project.