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Drywall recycling is not a common practice throughout the building industry even though it is one of the most used construction products. Over 15 million tons of drywall scraps end up in landfills in the United States every year. Thankfully, this is not the only viable option for drywall scraps. Many options for recycling drywall have gained prominence over the years as environmental concerns and resource conservation have become increasingly vital.
The innovative practice of recycling drywall scraps and other drywall waste involves repurposing and reusing the core gypsum material. This process diverts the drywall from landfills and forms it into valuable resources and materials. This practice not only minimizes waste but contributes to a more eco-conscious approach to building and renovation.
What is Drywall Recycling?
Drywall recycling is a process that includes collecting, processing, and reusing or repurposing gypsum-based drywall waste. This waste is produced during numerous projects like construction, renovation, or demolition. Gypsum, a naturally occurring mineral, is the most common product that is recycled from old drywall or drywall scraps.
The main goal of recycling drywall is to save the gypsum in the core, which is a product that is forever recyclable. This is one of the few construction products that can create a fully closed-loop recycling system. To achieve this, a standard system of quality control for end-products must be developed to ensure that it meets the quality standards of drywall manufacturers and other industries that utilize the recovered gypsum. Today, no such industry standards exist, making manufacturers hesitant about accepting recovered gypsum.
Importance of Drywall Recycling
Gypsum is a valuable material that can be diverted away from landfills and used in more productive ways. One of the most important reasons for recycling drywall is to reduce the amount of mining for primary ingredients to create new products. Recycling drywall saves energy and saves valuable natural resources. Recycling also reduces the amount of drywall waste in landfills. This waste takes up space in the landfill and releases hydrogen sulfide and methane gas into the air. These gasses have an unpleasant odor of rotten eggs and are toxic.
Steps in Drywall Recycling
The process of drywall recycling is a multi-step process that typically includes the following steps.
The collection of drywall waste from construction and demolition sites is a crucial step where the drywall waste is assessed, separated, packaged, and transported to a recycling facility. This step requires a systematized process to ensure the safe and efficient processing and handling of drywall pieces. The goal of this part of the process is to minimize contamination and maximize the amount of drywall being recycled.
- Sorting and separation
During this step, the drywall pieces are examined at the recycling facility to sort and remove any contaminants that remain among the drywall pieces. This step is necessary because even though there is an initial sorting at the job site, this is just a cursory examination.
A more thorough process will remove small items like nails, screws, and insulation particles. These recycling sites have specialized equipment and people with expertise to perform detailed inspections. These will ensure that the gypsum is pure from contaminants and that it meets industry requirements.
- Grinding or pulverizing
During this step, the gypsum is transformed from a waste product into a product that is valuable. Drywall scraps are crushed and shredded and then ground to reduce the size of the particles. The desired particle size depends on the intended end-use of the recycled gypsum. In some cases, the gypsum particles will undergo sieving and screening. This process can separate any remaining contaminants and oversized particles.
- Quality control
Quality control of the gypsum particles assesses the purity and composition of the pulverized gypsum. This is crucial in assuring manufacturers that the gypsum is up to industry standards. One of the primary methods for quality control is chemical analysis. Samples of the gypsum powder are tested to ensure that it has a high level of calcium sulfate dihydrate. They further test to determine if there are any microscopic impurities, to test that the moisture levels fall within acceptable ranges, and to quantify the particle size distribution.
- Reusing and repurposing
This step involves creating products from recycled and processed gypsum. The gypsum powder is transformed into valuable products and used in numerous applications. Reusing and repurposing are essential in maximizing the environmental benefits of drywall recycling. This process also contains a research and development arm to discover new ways to reuse old drywall and efforts to expand the market to broaden the appeal of these products.
Products from Recycled Drywall
Recycled drywall can be utilized to create numerous materials that help to reduce its environmental impact and create revenue to support local economies.
- Drywall sheets – Only 5% of drywall sheets in the United States today use recycled gypsum powder to form new drywall sheets. Yet, manufacturers can use recycled gypsum endlessly to create new drywall, reducing the need to obtain new gypsum.
- Soil amendments – Gypsum is a valuable mineral for amending soil. It adds important nutrients like calcium and sulfur to the soil, helps to improve water retention, and reduces the impact of salt in saline soils.
- Cement and concrete additives – Gypsum is a common additive in cement and concrete. It helps to extend the rate of hydration and setting time. This ensures a stronger and better quality cement or concrete product.
- Construction products – Recycled drywall scraps and gypsum are valuable in many construction processes. It can be used to create gypsum-based plaster, joint compounds, and non-structural building components.
- Industrial applications – Gypsum is a vital component in industrial products like ceramics, and glass and in the production of plastic and paper.
- Gypsum blocks – Gypsum blocks used to be a common construction material in the USA but are no longer produced or widely used. In Europe, gypsum blocks are highly popular due to their low emissions of VOCs. Researchers at Washington State University have used drywall waste to create a new construction block from 80% recycled waste. These blocks are waterproof and lighter than similar blocks like earth blocks, bricks, or concrete blocks. These blocks have not been cleared for construction use yet, but this process will hopefully renew interest in gypsum blocks in the United States.
- Ceiling tiles – Some recycled drywall products are useful in creating ceiling tiles that are common in commercial and residential buildings.
- Molded products – Recycled drywall products can be shaped into usable forms for specialized applications such as decorative architectural elements or soundproofing products.
- Soil erosion control – Recycled gypsum is useful in creating erosion control products such as erosion blankets and sediment control logs.
Difficulty in Recycling Drywall
Recycling drywall is not as common or easy in the United States as it should be, though recent efforts in the public and government sectors are increasing pressure to make it more available. States and municipalities differ across the United States in terms of drywall recycling. In many areas, only new drywall scraps can be recycled. Check with your local recycling center to see if they take drywall scraps, both new and used. They may not do this as a part of your regular service but you may be able to schedule a special pick-up. Habitat for Humanity is another group that takes unused drywall.
There are also certain companies that provide used drywall recycling in select states. USA Gypsum recycles used drywall. It is located in Pennsylvania but serves nine different states. Urban Gypsum is in Oregon. Both of these companies provide drywall recycling for contractors and are not open to the public. One company open to the public is GreenWaste Zanker Resource Recovery Facility in California. Check with online search tools to see if there are any drywall recycling companies in your area. Many of these are located in the Pacific Northwest and California.