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Washington State University professors and students are collaborating with contractors to repurpose construction debris as drywall blocks for a unique building system. Known as a Drywall Waste Block, they’re designed to transform low-value construction waste into a material that could substantially cut the cost of building a home.
The team at Washington State University began developing the drywall-based “bricks” in 2017 with a grant from the American Institute of Architects. They recently received an Amazon Catalyst grant to help move their project from a laboratory to a demonstration structure.
The blocks, which resemble masonry bricks, are made from 80 percent shredded drywall scraps and a binder made from industrial byproducts. Researchers partner with local contractors to reuse the debris. Students use a press and a minimal electrical power to build the blocks, which are lighter than bricks or concrete blocks.
“The bricks are similar to adobe or compressed earth blocks, but our blocks are superior, especially for insulation,” said David Drake, adjunct faculty at WSU’s School of Design and Construction. Another professor noted the material may be a little less strong than concrete block, but it is a better insulator.
WSU professors said the waterproof blocks will be tested over the next several months to meet building, seismic, compression strength, safety and fire codes based on American Society for Testing and Materials procedures. They will also examine how it weathers over time and further explore applications and costs. One team member suggested the drywall blocks could replace concrete blocks in low-rise affordable housing projects or possibly be used in patios, terraces or even fire pits.
Drake’s colleagues on the project include Taiji Miyasaka, professor in the School of Design and Construction, and Robert Richards, a professor in the School of Mechanical and Materials Engineering.
A prototype structure featuring the innovative bricks is on display at the “Make/Do: A History of Creative Reuse” exhibit at the Washington State Historical Society Museum in Tacoma. The exhibition, which runs through December 6, focuses on the history of creative recycling and reuse. Included in the showcase are various “second life” objects and artifacts, plus displays of architectural, cultural and contemporary examples of reuse and salvage.
Waste from building construction and demolition is a growing concern in the United States. Despite dedicated efforts to recycle many construction materials, low-value drywall makes up around half the non-recycled debris at construction sites.
Drywall, used in interior walls and ceilings, is cost effective but wasteful to install. Researchers estimate 12 percent of new construction drywall gets wasted during installation; additional drywall waste comes from demolition and renovation projects.
Contractors disposed of 534 million tons of waste in 2014, triple the volume since 2003. Construction of a 2,000 square-foot home generates more than a ton of drywall scrap. Some landfills won’t accept drywall waste.
When drywall, also known as gypsum board or sheetrock, is put into landfills, soil bacteria decompose the gypsum and produce a noxious gas and potential health hazards.
WSU’s drywall-to-bricks project has created buzz in several media outlets and industry communications, in part because of its potential to incorporate scrap material in home building rather than more costly building materials.
“It’s a fascinating project that demonstrates how effective scrap recycling is, worthy of further research, investments, and expansions,” exclaimed a blogger for a recycling company.