Because gypsum can be used for both agricultural and building purposes, recycling is the the obvious choice when dealing with discarded plasterboard.
While the recycling of construction materials is most often associated with the key structural components of a building, such as concrete, timber or steel, other internal elements also present excellent opportunities for re-usage.
Plasterboard, also known as drywall is an outstanding example. The material consists of gypsum plasters sandwiched between sturdy sheets of paper, and is used as the surface component for interior walls and ceilings.
The material is extremely popular in many parts of Australia, and a near ubiquitous part of office environments in the Sydney CBD.
The fact that the key ingredient in plasterboard is gypsum – a soft sulfate mineral that can also serve as a fertilizer material – makes it a prime candidate for recycling.
When used for agricultural purposes, the gypsum found in plasterboard improves soil quality by a number of means, improving its structure and raising water retention levels by breaking up clay, as well as providing important nutritional elements for plants.
Plasterboard can also be used for product-to-product recycling, and converted into new plasterboard at a rate of one part recycled gypsum to three parts raw gypsum.
Despite this, plasterboard continues to be a major source of defit waste in the Australasian building sector, accounting for as much as nine per cent of the waste dispatched to landfill in New Zealand, for example.
While the chemical composition of gypsum makes it easy to convert into fertilizer, once dumped into landfill, the sulfate material can cause heightened harm to the environment because in that kind of anaerobic environment, it produces large amount of hydrogen sulphide gas.
Dumping plasterboard also has an adverse impact on the bottom line of building companies given the exorbitant landfill levies currently being charged in many parts of Australia, including NSW, Victoria and Western Australia, the latter of which lifted the rate by 400 per cent last year.
For these reasons, the building sector has ample reason to stop dumping plasterboard and start recycling it for other purposes.
The recent defit of Governor Macquarie Tower – a primary element in one of the Sydney CBD’s biggest developments, provides an excellent example of this.
All of the plasterboard removed during the building’s defit were sent to Regyp, a disposal company that specializes in the recycling of abandoned gypsum.
Specialized equipment is used to convert the discarded plasterboard into high quality recycled gypsum products, which can be used for either manufacturing or agricultural purposes.