PVC for the construction sector
PVC is the most widely used polymer in building and construction applications and over 50% of Western Europe's annual PVC production is used in this sector.
PVC makes a major contribution to the quality, safety and cost-effectiveness of construction materials, as well as helping to reduce the environmental impact of completed projects. Furthermore, PVC has a versatility that helps it meet modern and future design needs. In addition to new projects, PVC is also widely used in refurbishment, where it often replaces traditional materials such as clay and wood.
Key properties
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Strong and lightweight - PVC's abrasion resistance, light weight, good mechanical strength and toughness are key technical advantages for its use in building and construction applications.
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Easy to install - PVC can be cut, shaped, welded and joined easily in a variety of styles.
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Durable - PVC is resistant to weathering, chemical rotting, corrosion, shock and abrasion. It is therefore the preferred choice for many different long-life and outdoor products. In fact, medium and long-term applications account for some 85% of PVC production in the building and construction sector. For example, it is estimated that more than 75% of PVC pipes will have a lifetime in excess of 40 years with potential in-service lives of up to 100 years. In other applications such as window profiles and cable insulation, studies indicate that over 60% of them will have working lives of over 40 years.
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Cost effective - PVC has been a popular material for construction applications for decades due to its physical and technical properties that provide excellent cost-performance advantages. As a material it is very competitive in terms of price - this value is also enhanced by the properties such as its durability, lifespan and low maintenance.
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Environmental impact - in lifecycle analyses and independent studies, PVC's environmental impact has been found to be favourable when compared with other manufactured materials used for construction. It is comparatively low in its energy and resource use during production, as well as in conversion to finished products.
As a thermoplastic, PVC can be recycled after it has been sorted into a single material stream and can also play its part in mixed plastics recycling. Facilities exist so that construction materials such as pipes, window profiles and flooring can be recycled at the end of their useful lives. Additional recycling facilities for waste PVC construction materials are being developed across Europe. At the end of a product's useful life, if not recycled, it can be safely incinerated or deposited in landfill.
PVC building products are lighter than those made of concrete, iron or steel. This requires less fuel and generates fewer emissions during transportation. They are also durable, so frequent replacement is unnecessary. Good thermal insulation of windows and cladding helps to increase the energy efficiency of buildings.
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Fire resistant - PVC is inherently difficult to ignite and stops burning once the source of heat is removed. Compared to its common plastic alternatives, PVC performs better in terms of lower combustibility, flammability, flame propagation and heat release. Newly developed PVC formulations (FR-PVC) have significant advantages in terms of lower acid emissions, smoke generation and enhanced fire resistance.
Although thermoplastic materials offer many advantages for cables they are nevertheless all flammable to a greater or lesser extent. PVC - because of its chlorine content - does not ignite easily nor does it continue to burn when the heat source is removed. The construction and telecommunications industries are increasingly aware of the need for new wire and cable coating products to have improved fire safety characteristics. This is especially true for electrical cables that are designed to carry power and communications for long distances, since in theory they could act as a pathway along which fire could travel. In particular, because cables are often arranged vertically through buildings, there is concern about potential fire propagation.
If untreated with fire retardants, PVC cables in a fire emit acidic gases and generate smoke. To address this requirement, new PVC formulations (FR-PVC) have been developed with significant advantages in terms of lower acid emissions and smoke generation, and enhanced fire resistance.
Good insulator - PVC does not conduct electricity and is therefore an excellent material to use for electrical applications such as insulation sheathing for cables.
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Versatile - The physical properties of PVC allow designers a high degree of freedom when designing new products and developing solutions compared to wood, aluminium and steel. Various ecobalance studies have been undertaken to compare the materials used in window profiles. These have shown that PVC has a good ecological balance when compared to wood or aluminium in this context.
Uses of PVC in building and construction
Window and door profiles
In the Life Cycle Assessment, conducted in 2000 by the UK Department for the Environment, Transport & the Regions, PVC window frames performed comparatively well. Some 40% of all European window profiles are made from PVC using about 600,000 tonnes - this represents more than 10% of Western European PVC production. Specifiers and consumers choose PVC windows because they are tough and durable, require low maintenance, do not rot, offer design flexibility, are competitive in terms of price, and can be easily processed and fabricated.
Pipes and ducts
Pipes are the major application for PVC in construction, accounting for 27% of all PVC products manufactured in Europe.
PVC pipes possess excellent technical qualities. In a range of applications from gutters to sewerage pipes they are able to fulfil demanding specifications. They are competitive in terms of cost, easy to install and require low maintenance. Pipes can be made in a range of profiles to meet specifiers needs.
The extrusion process, plus the fact that PVC is light in weight, allows long sections of pipe to be made, minimising the number of joints that reduces the cost of assembly.
PVC has very good chemical resistant properties and can be used above or below ground for the transport of many substances from driking water to oil and gas. PVC pipes are also used as ducting in the telecommunications industry for carrying cables and wiring.
Pipes made from PVC have good abrasion resistance, are not damaged by special equipment used for clearing blocked pipes and are resistant to damage from sharp-edged backfill materials.
PVC pipes can be easily coloured for different applications in line with EU regulations for underground pipe installations.
In domestic plumbing applications, PVC pipes are light and easy to install. They are also less likely to burst in freezing weather than the traditional alternatives and do not build up scale deposits. PVC pipes have the advantages of being a poor conductor of heat or sound.
Several pipe designs for sewerage have been developed; solid, corrugated and foam-core twin-wall pipes. Ribbed PVC designs used for underground pipes have increased rigidity and provide potential for weight savings. The ribbed designs have a smooth inner wall to allow free flow. These pipes also have much greater impact strength than clay pipes.
Foam-core PVC pipes have solid PVC inner and outer walls that enclose a cellular core layer. This technique can save up to 35% of material weight. Some manufacturers use recycled PVC pipes as a feedstock for new pipes. For example, triple-wall sewer pipes are made using thin outer and inner walls of virgin PVC with a thicker layer of recycled material as the middle layer. The recycled content of these pipes can be as high as 60% by weight. PVC liners and inserts can be used to repair damaged concrete or clay pipes.
Wiring and cable insulation
Electricity powers almost every aspect of our lives, either at home or at work. In many applications electricity is transported by wiring or cabling that is either insulated and/or sheathed with PVC, protecting users from potentially lethal electric shocks. Most brown goods such as video recorders, compact disc players and television sets utilise PVC cables. White goods such as cookers, fridge-freezers, washing machines and tumble dryers make extensive use of PVC cabling. Indeed, nearly all household wiring uses PVC.
In offices PVC cabling is extensively used in equipment for telephones, fax machines, photocopiers, computers and other office equipment. Rigid PVC can also be used for applications such as computer housings and keyboards, as well as for cable housings such as trunking, skirting and conduits.
PVC is used widely in general industrial applications such as power transmission cables (up to 6kV), distribution wiring, and in telecommunications and vehicles. Specialised formulations have also been developed for service in aggressive environments, such as arctic conditions, or in situations where fire performance and resistance to oils or outside weathering are essential.
Cable management systems
The use of cable management systems to contain cable installations both in the industrial and housing sectors has steadily grown in recent years, replacing traditional materials such as steel, or less commonly, aluminium. Such systems include skirting, trunking and conduit.
Cladding and roofing membranes
PVC cladding is designed as a long life product requiring little maintenance. PVC's durability, high thermal insulation and excellent weathering performance with good resistance to UV light and ozone, mean that cladding can remain in place for many years.
PVC roofing membranes are easy to install, totally waterproof, maintenance free, economically priced.
Flooring and wall coverings
PVC is the main plastic used for sheet and tile flooring. Vinyl flooring is hardwearing, warm underfoot, cost effective and easy to keep clean as it has a pore-free surface. It is low maintenance, needs no polishing or treating, and is hygienic and fire resistant. It is also easy to join separate sheets together by welding, which prevents water or moisture from seeping through gaps. In design terms, it is available in a wide variety of colours and finishes that can simulate tiles, wood or stone.
Vinyl coated wallpapers offer durable, washable wall coverings. They are long lasting and available in a wide range of colours, patterns and textures.
PVC is a versatile and adaptable material with suitable specifications to meet modern and future design needs. Modern architects often turn to the material in their search for innovative solutions to building design challenges.
From the use of tensile roofing structures to provide air and light, through to the specification of replacement window systems in building renovation projects, PVC provides the material - architects provide the inspiration.
Fencing
A new PVC product is set to revolutionise the commercial and domestic fence market. Designed to be used in both post and rail fencing applications, the system is lightweight and easy to handle. Made from PVC, the fence is totally weatherproof and colourfast. It has a recycled core and virgin outer skin, making it resistant to sunlight and environmentally friendly.
In comparison to traditional materials, the PVC fence wins hands down. It weighs just 9% of its concrete alternative, making it easy and safer to install. Fences are designed to keep out people and animals. PVC is extremely strong and resistant to vandalism, and unlike wood, will not rot or require costly annual maintenance. Indeed, the PVC fence has been tested successfully to withstand high impacts and strong winds.
Humanitarian aid
Third world countries battered by economic problems are often exposed to extreme climatic conditions. A natural catastrophe like a hurricane, a tidal wave or a drought can create disasters on an epic scale. PVC pipes, pumps and sheets form part of the aid effort to recreate infrastructure in disaster zones.
Benefits of PVC over other materials in construction
PVC is replacing traditional building materials such as wood, concrete and clay in many applications.
Versatility, cost effectiveness and an excellent record of use mean it remains the most important polymer for the construction sector. Substitution of PVC by other materials on environmental grounds would require additional research without proven technical benefits and at a higher cost. For example, as part of a housing renovation project at Bielefeld in Germany, it has been estimated that the replacement of PVC by other materials would lead to a cost increase of approximately €2,250 for an average sized apartment. Restrictions on PVC use for construction applications would not only have negative economic consequences but also have wider social impacts, such as in the availability of affordable housing.
Academic study 1: 'The environmental aspects of the use of PVC in building products' The Australian Commonwealth Scientific & Industrial Research Organisation (CSIRO), June 1996, updated April 2001.
This review of world-wide scientific research on PVC in building material was first produced in 1996 and then updated and expanded, initially in 1998, and then in 2001 so that subsequent new research could be evaluated. The report concludes that the adverse environmental effects of using PVC in building products do not appear to be greater than for other materials.
Academic study 2: 'PVC Life Cycle Assessment' Entec UK and Ecobalance UK, 2001.
An environmental comparison of PVC and several substitute materials performed for the UK environment ministry, the LCA concluded that the life cycle impacts of PVC are not significantly higher than those of alternatives. The study compared PVC and other materials in several applications and confirmed that there are relative differences in environmental performance based on application. PVC however does not fair substantially worse than any of the other materials tested.
Academic study 3: 'PVC and Sustainability - system stability as a yardstick, selected product systems compared'. Prognos AG (1999), published by AGPU
In a series of extensive workshops over a period of 30 months, experts from German PVC producers and converters conducted an extensive dialogue with scientists, NGOs and journalists. The results, known as the Prognos Study, assessed the contribution of four PVC products to sustainable development by evaluating their ecological, social and economic impact. PVC pipes, windows and cables proved to have good short and medium term potential for sustainable development, while special applications of PVC rigid films showed favourable short and long-term prospects. The results of the Prognos Study highlight areas for the industry to focus on in their efforts to achieve the long-term sustainability of PVC products. The experts recommended a strategy for all of the product groups investigated to the PVC industry that attempts to maintain the short and medium term market position by means of continual improvement. For example, by reducing weight, increasing heat insulation and increasing recycling for PVC window frames. However, Prognos stressed that it was difficult to take long-term investment decisions as the relevance of future risks remains uncertain.
