A roof is one of the essential components which protects the house from heat, cold, rain, and snow. A roof rests on a structural frame made of concrete or MS steel.
A concrete frame has columns and beams only; however, the steel frame is more complex in design and includes columns, trusses, beams, joists, and purlins. The concrete frame has a concrete roof or a deck slab. In contrast, the steel frame has roofing sheets over it.
A roofing sheet comes in different shapes and is made up of different materials. The use of roofing sheets is common in houses as well as commercial and industrial buildings.
It is to be noted that the development of industries has led to extensive use of roofing sheets than concrete due to the following reasons:
- Easy installation,
- Easy availability,
- Low cost,
- Multiple options and
- Lesser construction time.
Types of Roofing Sheets
As discussed earlier, roofing sheets are available for many purposes, i.e., residential, commercial, industrial, agricultural, etc. Each purpose requires roofing sheets to have specific properties, economy, and service span.
Roofing sheets are available in various types of material to meet the demands of different industries. These materials have different characteristics, and almost all of them are easily available in the market.
Types of Roofing Sheets as per the Design
- Corrugated Sheets
- Plain Sheets
1. Corrugated Sheets
The corrugated sheets have a repetitive design across their width. The design consists of alternate plain and ridge sections. The pitch of the ridge may vary with the type of material as well as the brand.
Also, the ridge may have a trapezoidal cross-section, semi-circular, semi-oval, etc. Another design for corrugated sheets consists of alternate peaks and troughs.
The repetitive design helps to provide the overlap between the two sheets along their length. For this purpose, each sheet has an overlap section on one end and an underlap section on the opposite end. Hence, the system of sheets is strongly built and doesn’t allow the water to leak through the joint.
The corrugated design is used in most roofing systems because it is durable, strong, leakproof, and reliable. The common application of corrugated roofing sheets is for garages, porches, and sheds.
2. Plain Sheets
The plain sheets are opposite to the corrugated sheets. These sheets have a liner cross-section in contrast to the corrugated sheets with alternate peaks and troughs. The plain sheets are difficult to join at the edges and need special care to make a leakproof joint.
Types of Roofing Sheets Based on Material
- Metal Sheets
- Galvanized Sheets
- Plastic Sheets
- PVC Plastisol Sheets
- Polycarbonate Sheets
- Asbestos Cement Sheets
- Colour Coated Sheets
- Bitumen Sheets
- Rubber Sheets
1. Metal Sheets
Metal sheets are available in steel, zinc, aluminum, and tin as base materials. These sheets are durable and last decades with due care and maintenance such as painting.
The metal sheets have the advantage that their scrap value is the highest among the other roofing sheets. The recyclability of these sheets makes them an environmentally viable option.
The long-term cost of metal sheets is comparable to others, considering the recycling option. Metal sheets have good fire resistance; however, they are prone to corrosion. The use of metal sheets is declining these days as the initial cost is higher than the other sheets.
2. Galvanized Iron Sheets
Galvanized iron sheets are similar to metal sheets, but the only difference is that they corrode less. GI sheets are made of carbon steel, and it contains a coating of zinc over it that is applied by a continuous hot dipping process. The zinc layer protects the sheet from corrosion.
The GI sheets are available in a corrugated and plain design, and they can be further protected with paints. Moreover, the GI sheets are resistant to minor abrasion and/or mechanical damage.
3. Plastic Sheets
Plastic is a material made of chains of molecules called polymers. Plastic is a versatile material resistant to corrosion, strong, durable, and can be installed easily.
It is available in various forms, such as polycarbonate, acrylic, polystyrene, and PVC. The plastics are available in opaque, translucent, and transparent variants.
4. PVC Plastisol Sheets
Plastisol is a rust-resistant paint. The metal sheet with plastisol paint and PVC rolled over is a PVC plastisol sheet. It is very durable and has an appealing finish.
5. Polycarbonate Sheets
Polycarbonate is a type of plastic that is very popularly used as a roofing material. It is easy to install, lightweight, and economical. The common usage of polycarbonate sheets is in large-scale industrial and commercial buildings. You can choose among the multiple thickness options available.
Another benefit of using a polycarbonate roofing sheet is its weather resistance and durability. These sheets are unaffected by rain or snow, and thus, the maintenance cost is very low.
Also, polycarbonate sheets are good insulators of heat and are also available in transparent and translucent textures with multiple color options. They also filter harmful UV rays from the sunlight.
6. Asbestos Cement Sheets
Asbestos cement sheet or AC sheet comprises 8% chrysotile fibers mixed with cement mixture. These sheets are corrugated, and at the time of manufacturing, they can also be molded into any desired shape and size. The thickness of an AC sheet is approx 5.8 mm.
AC sheets require zero maintenance as they are highly durable. Also, they are easy-to-install, strong, and durable roofing materials for warehouses, factories, low-cost housing, and practically any structure needing a roof.
Another advantage of AC sheets is the fire resistivity. These sheets are very cheap. However, the fiber released into the air with time may cause air-borne diseases.
7. Colour Coated Roofs
You might have noticed these on the warehouse or garage roof. Color-coated sheets are available in various colors, and you can choose the color of your choice. Aluminum is the most common material used for color-coated sheets, and they are fire-resistant.
8. Bitumen Sheets
The bitumen sheets are available in corrugated as well as in plain design. As the name suggests, these roofing sheets are made of bitumen mixed with fiber. They are durable and have a distinctive black appearance.
The main advantage of bitumen roof sheet is that it is resistant to corrosion and can shed water quickly. The main disadvantage is that it absorbs the sunlight’s heat, which increases the temperature inside the building.
9. Rubber Sheets
Rubber sheets are used over the existing roofing sheets to provide waterproofing and heat resistance. The ethylene propylene diene monomer (EPDM) rubber is used, which is rolled over the surface and glued or taped. An EPDM of thickness 1.2 mm is 59 times more reliable waterproofing than a PVC sheet.