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Polycarbonate Roofing

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The ideal way to maximize natural light in interiors is by maximizing the amount of light coming in through the roof. Polycarbonate transparent roofing sheets permit optimum daylight and its light weight allows for architectural and design creativity. The other key advantages of using polycarbonate for roofing are the increased resource efficiency and reduced environmental impact.

Polycarbonate roofing sheets are manufactured from high quality thermoplastic material which is strong, moldable, shatterproof and lightweight. It’s just 1/3rd the weight of acrylic and 1/6th as heavy as glass. Product applications range from industrial and commercial to residential roofing. The inherent lightweight nature of the polycarbonate roofing helps eliminate the excess load on the structure and is available in a wide variety of colors, styles and textures to complement specific designs. Furthermore, unlike conventional or standard roofing, the vast majority of polycarbonate roofing materials are manufactured from recycled components, thereby greatly reducing the impact on the environment. The two commonly used varieties of polycarbonate roofing are clear polycarbonate and foam back polycarbonate sheets.

Clear Polycarbonate sheets are clear or lightly tinted and frequently used in place of glass or acrylic applications. It is mainly used in areas where natural light is needed through the roof such as greenhouses, solariums, skylights, sun rooms and patio rooms. Most panels also have a protective film layer to filter out UV rays from the sun. In contrast, Foam back Polycarbonate sheet is not translucent and is used for more traditional purposes. The panels come in a variety of colors and appear like corrugated metal roofing sheets. However, unlike metal, polycarbonate panels do not rust and the foam backing provides extra insulation and noise dampening. This type of roofing is used mainly for industrial buildings like warehouses or as flat or slightly sloped roofs for porches, pergolas, sheds, carports and small residential buildings.

The polycarbonate roofing apart from being available as plain, colored and embossed sheets is also manufactured as corrugated sheets. The corrugated roofing characterized by the typical ridges and grooves pattern has either round or box-type profile which makes them strong and allows water runoff. Alternatively, a high quality, multi-wall polycarbonate glazing sheet helps enhance thermal insulation and energy efficiency through its thin wall tunnel rectangular structure and multiwall construction that traps air between the layers. The sheets also display an exceptional fire performance, do not give off toxic gases and are classed as self-extinguishing. In addition, Twinwall with a surface treatment film on both sides of the sheet provides almost total resistance to degradation from UV radiation in sunlight, as well as long-term high light transmission. Also, Twinwall sheets can be cold bent into tight radii and used in many curved applications such as arched walkways without pre-forming.” Pradeep Rao, General Manager- Western Region for Tuflite Polymers Limited adds, “All kinds of Polycarbonate sheets posses a combination of excellent outdoor properties including superb weather and temperature resistance and thus are primarily used for harnessing daylight. The material is virtually un-breakable, is flexible, light weight and fire retardant. The supporting structure for Polycarbonate roofing is fabricated form mild steel square or rectangular tubes based on the structural design. Sheets are usually clamped between top & bottom aluminum sections with EPDM Rubber gaskets for water tightness. This system is known as Dry Glazing. On the other hand, profiled / corrugated sheets are fixed with self tapping / self drilling (STSD) fasteners exactly like the metal profiled sheets.”

The performance of polycarbonate is being constantly improved through technical and scientific innovation. New applications and products are being explored to provide consumers with additional benefits. For example, polycarbonate roofing sheet with combination of additives and tints that blocks out significant amount of glare without impacting the quality of light that comes through the panel or its aesthetic appeal. The corrugated sheets available in clear bronze, grey, opal and cream provide high UVA & UVB rays protection which makes it most suitable for outdoor areas like the patios, pool decks and verandahs. Another polycarbonate roofing type has a two side proprietary UV-protected surface that provides superior resistance to discoloration, loss of light transmission and loss of impact strength due to weathering. The roofing discoloration in this type of sheet is not more than a delta Yi (yellowness Index) of 4, while regular polycarbonate roofing sheets display discoloration change of more than a delta Yi of 10.

Another product in this segment is the clear twinwall polycarbonate sheet filled with aerogel. It combines best-in-class thermal insulation, good load bearing properties, high light transmission and excellent weather resistance. The sheet is lightweight, impact resistant and easy to install. The product is designed to be used just like traditional polycarbonate roofing but offers better insulation properties than most triple glazing or argon filled double glazing. The sheets are produced with a coextruded UV-protective layer which is homogeneously fused with the sheet material. The roofing offers an effective means of reducing carbon footprint of a building and is specifically developed for roof glazing applications in conservatories, roof glazing in passive houses, skylights, northlight glazing and industrial glazing.

A similar energy efficient product is a polycarbonate profiled extrusion which has a co-extruded layer of ultraviolet-stabilized surface protection on the weather side and microscopic reflective particles incorporated in the core material. The product eliminates about 60% of the sun’s radiated heat and reduces the cooling load of the building, which in turn reduces the use of air-conditioning and can lead to energy savings of between 10% and 30%.

Case Study

Tuflite Polymers Limited, India offers complete range of Polycarbonate Sheets & Solutions including Solid / Embossed Polycarbonate Sheets, Corrugated / Profiled Extruded Polycarbonate Sheets, Multiwall Polycarbonate Sheets, as well as Geloy Co-extruded UPVC Roofing Sheets & Decorative Roofing Tile Sheets.

Pradeep Rao
General Manager- Western Region for Tuflite Polymers Limited

The company has extensively used polycarbonate sheets for skywalks, Foot Over Bridges (FOBs), atriums in shopping malls and to cover areas in educational institutions & hospitals. The lightweight sheets are also installed as daylight glazing in industries, warehouses, railway stations and terrace coverings of bungalows and large apartments. The technology used is known as extrusion and usually the machinery is sourced from Italy or Germany. The material is termed as engineering thermoplastic. Rao says, “There is a steady growth in demand for polycarbonate roofing products in India. The approximate consumption of polycarbonate material for roofing applications is close to 13500 MT per annum. Some of the major projects executed using Polycarbonate roofing include, roof for skywalk in Bandra and roofing for ramps in open area at a commercial building in Bandra-Kurla complex in Mumbai.”

Bandra Skywalk

This was the first Skywalk to be commissioned by MMRDA with almost 1.3km length and a roof area of about 7500 square meters. The project threw up challenges mainly because the work was to be carried out over and around the busy Western Express Highway. The roofing installation was completed in 40-45 days and was the predecessor of all subsequent skywalks that came up in Mumbai. Material used was 16mm Multiwall Triple layer Sheets in green & opal white coloured panels used alternately. The main Contractor for the work was Das Offshore Engineering Pvt. Ltd. – Belapur, Navi Mumbai

Bharat Diamond Bourse

The commercial building at BKC required replacing of FRP with Polycarbonate Modular System over 5 Ramps with total area of approximately 25000 sq. ft. Architect Reza Kabul & Associates and the building owner did not want any visible fixtures on external surface as the ramps were at eye level on the ground floor. To address clients need, company used Sun Module 12mm Honeycomb Bottom Seam System in opal white colour and the installation was completed in just 20 days.

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