Plastic is one of the most widely used materials in the world. The AEC (Architecture, Engineering and Construction) industry also uses different forms of plastic extensively in the construction, maintenance and operation of built structures. The many advantages offered by the use of different categories of plastic in buildings make it a sought-after material. Read on to learn all about the various types of plastic and their uses in construction.
What is Plastic?
Plastic is a manufactured material made up of synthetic components mainly derived from petrochemicals and natural gas. Long chains of carbon atoms attached to hydrogen, sulfur, oxygen, chlorine and/or nitrogen form the organic polymers that shape plastics. Since the invention of Bakelite—believed to be the first completely synthetic plastic—in 1907, different types of plastic have been developed and widely utilised in every industry. Plastic in construction today is a part of various aspects—such as roofing sheets, cladding and insulation panels, doors and windows and piping systems—due to the many benefits that its usage offers.
Types of Plastic Materials Used in Construction
Some of the most commonly used plastic building materials are:
Acrylic
Acrylic, also known as Polymethyl Methacrylate (PMMA), acrylite, lucite and perspex, is a thermoplastic known for its absolute transparency. Some of the types of acrylic sheets are cast acrylic sheet, continuous cast acrylic sheet, extruded acrylic sheet, sign grade acrylic sheet, acrylic mirror sheet and marine grade acrylic sheet.
Important Properties
- Light transmission > 92% (equal to the transparency of the finest glass).
- Good flexural and tensile strength and high impact resistance.
- Poor resistance to many chemicals- it can dissolve or swell in many organic solvents.
- Highly resistant to temperature and humidity variations.
Applications in Construction
- Shatter-resistant panels for windows, skylights, partitions and security barriers.
- Acrylic plastic roofing sheets are used in various colours, profiles and designs.
- Sanitary ware such as sinks, wash basins and bath tubs.
- Interior elements such as furniture, laser-cut partitions and lights.
- Water-based acrylic sealants, adhesives and resins are used for filling gaps and cracks.
Polyvinyl Chloride (PVC) and Unplasticised Polyvinyl Chloride (uPVC)
PVC and uPVC are the most widely used plastic building materials. While uPVC does not consist of plasticisers and is often used as a substitute for wood, PVC is more brittle due to the addition of plasticisers like phthalates and BPA (Bisphenol A).
Properties
- Resistant to weather changes, corrosion and strong chemicals.
- PVC is flexible and can be easily moulded, while uPVC is more rigid.
- Although uPVC is more expensive than PVC, both are extremely affordable.
- Air-tight and water-resistant.
Applications in Construction
- uPVC windows and doors are affordable and maintenance-free.
- PVC pipes are used for water supply and drainage and sewer lines, while uPVC is used for making heavy-duty plumbing pipes.
- PVC roofing sheets are available with different coatings, profiles and finishes.
- PVC electrical conduits and wire sheathing.
- PVC roofing panels and flooring sheets are lightweight and strong.
Polycarbonate
Polycarbonate plastics are formed by multiple groups of Carbon atoms arranged in different layouts. It is manufactured through different processes like injection moulding, blow moulding, vacuum forming and CNC machining. Different grades with varying properties like flame retardant, impact resistant and UV-protected sheets are available.
Properties
- High impact resistance, but is vulnerable to scratches.
- Can withstand extreme temperature variations, UV radiations and chemical exposure.
- It is very flexible and can undergo deformations without cracking or breaking.
Applications in Buildings
- Polycarbonate roofing sheets are extremely strong, versatile and durable.
- Used as a substitute for glass in windows and skylights.
- Used to make LED lights for both exterior and interior applications.
- Polycarbonate cladding panels can be used on roofs and walls.
Polyethylene
Polyethylene (PE) is a plastic polymer made of hydrocarbon atoms obtained from natural gas or petroleum. Although it has many desirable properties for usage in buildings, its exposure to normal solar radiations can produce greenhouse gases like methane and ethylene, thus raising questions on its practicality.
Properties
- Available in three different densities- LDPE (Low Density Polyethylene), MDPE (Medium Density Polyethylene) and HDPE (High Density Polyethylene).
- Has very high chemical resistance.
- The transparency varies with the type, ranging from fully transparent to opaque.
- Moisture and vapour-resistant.
- High ductility and electrical insulation properties.
Applications in Buildings
- High density plastic sheets are made with High Density Polyethylene (HDPE).
- PE sheets are used to seal rooms and prevent entry of air and moisture.
- Damp proof membranes for lining foundations are made with PE.
- PE (particularly HDPE) pipes are used for water supply and drainage systems.
- Floor, roof and wall insulation systems utilise PE foam.
Polystyrene
Polystyrene is a synthetic material made from a liquid petroleum called styrene. Three forms of polystyrene are commonly available- solid plastic, foam and film. It can be combined with other plastic material types to produce versatile colours, forms and properties.
Properties
- It is a colourless, hard and brittle plastic.
- Melts to a liquid when heated and freezes to a brittle glassy state when cooled, allowing it to be easily moulded.
- Has low thermal conductivity, making it a very good insulator.
- Good chemical resistance, but low oil resistance.
Applications in Buildings
- Expanded Polystyrene (EPS) and Extruded Polystyrene (XPS) are used to make sandwich panels for roofing and wall systems.
- Polystyrene foam is used for insulation in cold storage facilities, freezers and in walls and roofs of industrial buildings.
- Styrofoam and EPS are used in Insulated Concrete Forms (ICF).
- EPS blocks are used for building lightweight and affordable walls.
Composite Plastics
Composite plastics refer to two or more different types of plastic or other materials combined together. Commonly, fibers, fillers and other particulate matter are blended with plastic to produce materials with optimised physical and mechanical properties for specific purposes. Some examples of such plastics are: Fibre Reinforced Plastic, Polytetrafluoroethylene (PTFE) and Glass Mat Thermoplastics (GMT).
Applications in Construction
- Fibre Reinforced Plastic (FRP) is used for making doors, windows, columns, beams and rebars.
- Doors, windows, cladding panels and fencing can be made with Wood Plastic Composite (WPC).
- Epoxy resin is used in the manufacture of paints, adhesives, primers and flooring panels.
- Tensile membranes for roofing structures are made with PTFE (Polytetrafluoroethylene).
- PVDF (Polyvinylidene Fluoride) coatings are used on metal surfaces like cladding and roofing panels to prevent corrosion.
Ensuring the Best Plastic Varieties in Construction
With their extensive range of applications, plastic material types have become integral aspects of buildings and their construction processes. Various types of recyclable plastic, such as HDPE and PVC are becoming increasingly popular in modern construction as they have reduced negative impacts on the environment. Brick & Bolt, a design-build company in India, always ensures the use of premium plastic varieties with extensive quality checks (including 470+ QASCON tests) in its construction projects. To get the best materials at the lowest prices in the construction of your dream home, get in touch with Brick & Bolt today!
Hemali Patel