Thursday, 27 August 2015

THE GREEN ROOF OVER OUR HEADS

In the past year, roofing systems that can meet energy efficiency and also impose lesser load on the structure gained popularity among owners and designers alike. The choice ranged from metal, plastic and fabric to tiles and solar covering. The next year brings with it even more innovative roofing and innovative insulation materials.

With new advances in materials and technology, lightweight designs and the innovative resources are replacing heavier roofing materials. The introduction of lightweight concrete as a material for roof decking and as an insulation system provides a variety of economic and environmental advantages. It is consistent in compressive strength and density, provides thermal R-value of R-30 and as these roofs is an integral part of the building structure, the concrete acts as the insulation reducing the dead load of a structure. Insulating concrete roof is produced either with cellular concrete (preformed foam) or with expanded aggregate concrete (perlite or vermiculite).

Synthetic Thatch

To add the traditional architectural style in a cost effective way, concrete roof tiles are being used in projects. Alternatively, the tiles made from natural materials like sand, cement and iron oxide pigment remain cool in summers and are highly weather resistant. Likewise, synthetic slate tiles manufactured from post-industrial and post-consumer polymers called ACE compound, are environmentally safe material for roofing. It is fade resistant, maintenance free and 100% recyclable.

Moneir Concrete Tiles

The architectural metal roofing (steel, aluminium, copper, zinc, stainless steel and titanium) available in vertical standing seam, corrugated, tile profiles and horizontal panels can simulate the look of standard shingles, wood shake, slate and tile. The metal roofs with oven-cured and pre-painted organic coatings incorporate new “cool pigment” technology providing solar reflectance and high infra-red emittance even with darker colours. This cool metal roofing typically has a minimum recycled content of 25% and is 100% recyclable.

Synthetic Slate Tiles

A roofing material that is gaining ground for both exterior as well as interior applications is tensile fabric. The tensile fabric acts as a light weight roofing offering dynamic forms and functionality. The past years witnessed its wide use in airports, stadiums, mall atrium's, restaurants and as skylights and porches in residences. For structures where high performance in thermal insulation is desired, the newer single layer low- E membrane fabrics are now being used. The product has a lower solar factor, meets flame retarding standards and is a 100% recyclable textile. “The fabric structures are engineered to meet the requirements of most building codes and standards worldwide. It provides speedy installation or relocation as an alternative to conventional construction.”

Copper Zinc Roofing

A category that is fast developing is of uPVC roofing that is heat, chemical and corrosion resistant and has sound insulation properties. They are fast replacing conventional asbestos, metal G.I. sheets and fibreglass sheets. An innovative roofing option that emerged for resorts and vacation homes was the synthetic thatch made from recycled plastic. The roofing is not only similar in looks to natural thatch but is as environment friendly. The roofing apart from being no maintenance is structurally stable and UV resistant. “The synthetic thatch roofing panels can be conveniently installed on a pre-existing roof and give the natural thatch look. The roofing does not attract insects, rodents or birds and does not need replacement for almost ten years”.

Tensile Fabric Roofing

According to roofing industry experts, environment friendly metal roofing will hit its all-time high. Conventional roofs are being replaced with insulated colour coated sheets and tiles that are energy efficient, quick to install, low maintenance and assure safety. Gray and dark blue is the popular colour choice while, deep green and earth tones will continue to find favour that draw on natural surroundings.

With the increased focus on Green buildings, recycled materials, green roofs and solar panels are predicted to have increased demand in coming years. High performance and green roofs though common around the world are steadily gaining popularity in India. They are likely to become technically more feasible and economically reasonably in next few years.

Talking of renewable energy, solar roof covering too is transforming into a more aesthetically pleasing materials such as flexible thin-film to easily integrate photovoltaic into the metal roofs or solar shingles that can be bolted on existing roof and work like the conventional larger solar panels but do not add extra weight and are much more visually appealing.

Solopower Roof – flexible solar films

Solar films roofs

Originally invented by DuPont as an insulation material for the aeronautics industry, ETFE (Ethylene Tetra Fluoro Ethylene) is fast becoming one of the most exciting materials in today’s design industry. The makings of ETFE as a long term construction material will lie in the development of various high-tech coatings and methods of printing which will modify not just the translucency but also the thermal and acoustic properties of the fabric. For instance, Architen Landrell Associates, UK is running an active test programme to develop IR reflective coatings that will allow multilayer ETFE systems to transmit visible light yet block (insulate) infra-red transmission.

ETFE Roofing

Innovations for Sustainability
  • A product under development by The Speciality Group, Australia is composite and lightweight solar   roofing in sheet form, from UV cured polyester resin prepare. The technology aims at building integrated photovoltaic product, where the roofing material itself has solar cells embedded into it.
  • Bayer Material Science has engineered a photovoltaic module for producing electricity and a solar air collector that captures the sun’s heat. “The two modules don’t just use solar energy; they simultaneously serve as roofing and in the case of the air collector, even intelligently increase insulating performance.
  • Transparent solar modules offer the most attractive building integrated PV solutions. They use double low iron tempered glass with solar cells laminated in between and are ideal for roofs, skylights and façades. The modules can also be part of shading devices named shadow-voltaic systems.
  • New insulating materials like Nanogel and Icyene are patently high-tech and non-organic, yet their special qualities permit new applications such as spray-in-place quick fixes, and translucent insulating ceilings. Aerogels have an extremely small pore, which makes them one, the best thermal insulators in the world. Nanogel® from Cabot Corporation is light and transparent, while being extremely insulating to create translucent walls and ceilings that will let the light in, but keep the heat out.