Cover Story

Warehouses: What's on Top?

June 2018
CW explores popular roofing systems for warehouses and Indian success stories.

Burgeoning manufacturing activities, an emerging organised retail sector and increasing private and foreign investments in infrastructure for logistics have combined to make warehousing one of the crucial components in the economic value chain. In fact, by 2020, the Indian logistics market is expected to grow at a CAGR of 10.5 per cent, primarily driven by the growth in manufacturing, retail, FMCG and e-commerce.
So what's the need of the hour? (A structure that is safe, durable, well-insulated, fireproof, incurs minimum maintenance and is easily erected for early revenue generation is critical for the warehousing sector to overcome challenges, as well as maintain, improve and sustain competitiveness, responds Mahendra Pingle, Deputy General Manager-Market Development, Tata BlueScope Steel. (Low cost, light weight and low maintenance were and remain demand triggers for warehouses. Modern technology has added precision, safety, insulation, durability and aesthetics. Life-cycle cost studies confirm that steel roofs are among the most cost-effective roofing systems available for a warehouse.

(The demand of warehousing is growing steadily in India over the past few years, whether it is large logistics parks, industrial warehouses for manufacturing companies or agriculture warehouses for the Centre and state governments, says Gautam Suri, CTO & Founder Director, Interarch Building Products. (We are PEB and roofing vendors for large logistics parks such as Indospace, Safexpress, Delhi Cargo Service Centre, Gati and Vijay Logistics. In the government sector, we have delivered buildings for Concor, Central Warehousing Corporation, Rajasthan State Warehousing Corporation and Madhya Pradesh State Warehousing Corporation, to name a few.

Interarch's products range from typical screw-down roofing panels to high-end standing seam roofing systems. (One of the company's roofing products is TRACDEK Hi-Rib, a pierced fixed roof and wall covering system, which consists of structurally engineered profiled panels that are available in single length (up to 12 m) and are fixed by means of self-drilling fasteners, says Suri. This apart, TRACDEK Klippon is a concealed fixed snap-on seam roof or wall covering system, used for roofing large span factories, warehouses, commercial, educational, institutional, domestic and recreational buildings. Also, TRACDEK SS-2000, known as TRACDEK vertical leg structural standing seam roof system, is designed to be installed over open framing; 15 mm plywood or a composite roof assembly may be used as alternate substructures.

Success stories
Global e-commerce major Amazon wanted to ramp up its fulfilment centres (FCs) in India.
Tata BlueScope Steel supplied cladding material for the project. ZINCALUME steel was chosen for the roof owing to its heat reflectivity and anti-darkening properties (unique surface coating than other Al-Zn alloy coated steel brands). The lustre of this sheeting material remains intact for longer in addition to long-lasting durability. COLORBOND steel and SURFMIST colour have been used for wall cladding (horizontal laying of sheet), enhancing the overall aesthetics of the building. Another example is Trent Retail's Westside warehouse in Vapi. The structure demanded an unconventional signature design arrangement followed by Trent. The company's COLORBOND steel offered design flexibility and customisation. In fact, COLORBOND steel has been extensively used for many warehousing and land parcel projects in India, such as Indospace Industrial and Logistcs Park, Prakhhyat Infra Projects, Arshiya International, etc.

For its part, Interarch delivered a greenfield air cargo terminal building at Delhi airport; the cargo building is spread over 70,000 sq m. The company completed the projects in a record 12 months, from engineering and manufacturing to logistics and erection of the building. In this project v a cargo warehouse (G+2) multi-storey building v Interarch Building Systems used 5,850 mt of built-up pre-engineered steel buildings; autumn red and off-white Tracdek Hi Rib wall cladding system; and off-white Tracdek SS-2000 roofing system.

Current Trends for Roofs
Roofing is one of the most important aspects of construction, for both industrial and warehouse buildings, and it is an industry that has continued to grow and develop in recent years. Gautam Suri, CTO & Founder Director, Interarch Building Products, shares some of the latest trends:

Daylight panels: Buildings are equipped with daylight panels to provide natural light during the day, which further reduces energy consumption. Interarch installs around 3-5 per cent of daylight panels of the total roof area.

Cool roof or high reflective roof: Cool roofing systems reflect sunlight and, therefore, do not absorb heat. Interarch uses SRI-value light colour roofs that reflect the sun rays, further reducing power consumption of the warehouse building.
On-site roll forming-standing seam: Facility of on-site roll forming eliminates panel end lap condition. Panels are manufactured µat-the-eaves', enabling single-length panels on long roof runs.


Colour-coated Roofs in Warehouses
Despite the plethora of roofing materials available within the construction sector, steel is the most preferred metal owing to its high strength and longevity. Mahendra Pingle, Deputy General Manager-Market Development, Tata BlueScope Steel, shares why:

Long-lasting durability: In case of fire protection, roof and wall cladding sheeting are used as an envelope. The pre-painted ZINCALUME steel(ie COLORBOND steel) is resistant to the spread of fire. The high strength of the base steel and a superior paint system combined with outstanding corrosion resistance from the metallic coating makes COLORBOND steel suitable for applications in harsh environment. The strength of a metal roof is high with lower weight v a benefit more often realised in seismic belts and retrofitting projects.This reduces the load on the overall structure, making it lean.

Superior aesthetics: COLORBOND steel offers architects, designers and builders a lightweight, strong and aesthetically pleasing solution for almost any type of building and environment. It enables unconventional shapes and sizes. Signature-styled warehouses typically opt for COLORBOND steel, which comes in a multiple colour range. ZINCALUME steel, a substrate for COLORBOND steel, has a superior ability to resist corrosion up to four times longer than galvanised steel of equivalent coating thickness, curtailing issues like rusting, fading, peeling and chalking possible on other metal roofs. COLORBOND steel is not simply painted; it is a total system of having seven unique layers that deliver longer life and superior aesthetics.

Thermally efficient and environment-friendly: Goods stored in warehouses, though under conducive temperature control, may consume higher energy if the roof is not thermally efficient. Roofs that are highly reflective and emissive, such as pre-painted metal sheets, significantly reduce heat gain into the building. COLORBOND steel with THERMATECH technology offers higher solar reflectivity and reduces the inside temperature by up to 6ªC, thus ensuring thermal comfort. Being energy-efficient, it reduces the overall energy cost.