The Technology Behind Bricks
By Brett Martin
In Hanson Brick's fully computerized Monroe 3 brick plant, computerized robot arms unload green bricks from a conveyor belt and place them on the kiln car for drying and firing.
Fifty years ago, masons had one choice for brick: red brick. Today, the selections have increased exponentially, allowing for an ever-expansive range of options.
"Technology has allowed for more brick sizes, textures and colors. For instance, rollers attached to the production line after the clay is extruded can create rolled edges, dents and other 'aged' markings and texturing on the brick faces," said Dave Peters, project engineer for Hanson Brick & Tile in Charlotte, N.C. "This type of automated procedure can also create simulated tumbling or brick that has a beaten or aged appearance."
Greater flexibility in brick production and advancements in coloring techniques have also allowed manufacturers to develop a more diverse product line to meet any type of design, he said.
"These production advances have allowed us to more quickly respond to market demands for a certain brick color, texture or appearance than in any time before in our brick manufacturing history," Peters said.
"The dimensional quality is so consistent now, and that dimensional tolerance makes it so much easier for masons," said Andy Rogers, vice president of sales for Palmetto Brick Company in Wallace, S.C., which makes about 160 million bricks per year — about 442,000 bricks per day — in three plants. "If they're the same size, it's so much easier to lay them. Masons won't end up with different lengths at corners."
Manufacturers are able to offer brick shapes for specific architectural detailing, as well as angular, soldiered corners, and radial bricks that help masons avoid mortar lines at the intersection of walls.
"Innovation in brick shapes helps masons on the job site by reducing the amount of labor needed to create a certain design element in a masonry-clad structure," Peters said. "For example, Hanson's bonded jack arch and other bonded arches, which come pre-assembled, do not require any brick cutting or measuring on the work site. This significantly reduces the amount of time needed to install the arch and reduces work site waste."
Gregg Borchelt, vice president of engineering and research for the Brick Industry Association (BIA) in Reston, Va., said architects need to stay abreast of changes in bricks so they can adjust their design and details accordingly.
"For example, hollow brick cannot be laid with as large of a projection or recess as solid brick," Borchelt said. "Masons will appreciate the lighter weight of thinner and hollow brick. Foundations and support structures can be reduced as a result of the lighter weight of these brick."
In fact, lighter weight cored brick has garnered appreciation. "They're probably one-third to one-quarter lighter," said Kemper Wauford, estimator for Brothers Masonry in Phoenix, who has 20 years of masonry experience. "It's more user friendly. You can lay more brick."
Another improvement is the vast number of brick colors and textures now being offered. The Robinson Brick Company in Denver, for example, offers nearly 100 colors and manufactures bricks that have a distressed look.
"As the years have gone by, the variation of offerings has increased," said Tony Fabrizio, vice president of engineering and quality for Robinson.
"Automation, in general, in the brick industry is the biggest trend and improvement in the last 10 to 15 years," Fabrizio said. Robinson Brick introduced robots into its plant in March 1997.
"Everything used to be done by hand. It was a very labor-intensive operation," said Brent DeFore, president of Streator Brick, Inc., in Streator, Ill. "Now, human hands don't touch the brick. It's basically all automation."
Robots now handle the bricks during manufacturing for most modern plants. Fully computerized plants typically only require supervision by employees who can ensure the robots are working properly.
"The mason is the first person who touches [the brick]," Palmetto's Rogers added.
Since they have to meet specifications by the American Society for Testing and Materials (ASTM), the bricks are going to perform well for the architects, designers and masons, and have a more uniform shape and quality, DeFore said.
"Automation and computerization of brick plants has allowed for increased efficiencies in production, as well as greater consistency of quality from brick to brick," Peters said. "The use of machines and automation has allowed brick manufacturers to provide a more consistent product and create less waste during the manufacturing process."
Better control of the manufacturing process also has resulted in better bricks, manufacturers say.
"The overall quality of bricks over the last 20 years has definitely improved. The quality control of the brick industry is 10 times better than it used to be," said Josh Higgins, principle with Higgins Brick Company in Redondo Beach, Calif., and the fourth generation of his family to work for the company. "Overall, the quality now is very good."
Technology has also impacted aesthetics. Manufacturers can more easily and cost effectively change colors and textures, since they're now added before the firing process, which helps with the design of buildings.
"Architects and design-build teams have the most to gain from a mass-produced, quality brick product that is available in a wide variety of styles," Peters said. "The more options we give them, the better we can help their design vision come to life."
The extrusion method keeps air out of the bricks, making them denser, while giving the bricks more strength and sustainability, Higgins explained. Technology has also improved the firing process.
"At the end of the day, the biggest advances are in firing and kiln technology," he said. "The real change is in the firing temperatures. We can electronically control the temperature so the firing curves are set."
The preheating, burning and cooling of the bricks in the kiln is done in zones that have closely controlled temperatures, Higgins said. "The burners are so efficient. We can warm up zones and cool down other zones in the kiln," he added. It used to take the company a month to make a batch of bricks, including setting them out in the fields to dry; Higgins Brick can now make a batch in four days.
In addition to greater control over the kilns, manufacturers have improved their testing methods. They can now test bricks in labs and determine their properties before they're manufactured.
"Now, every company has a lab and everybody knows the shrinkage," Rogers said, pointing out that bricks typically shrink 7 to 8 percent during manufacturing. "Most of the time, a very, very high number of bricks have already been tested in a lab. We know exactly what is going to be coming out."
Fabrizio said his company conducts lab tests as part of research and development, and also to confirm that the bricks being manufactured meet specifications.
"In the early phases, we test the physical properties and test to make sure the brick meets the quality standards and color we publish," he said.
"You can compare it to other building products, like lumber, and see that [brick has] gone up only a fraction. It's still under-priced," Rogers said. "We have to be more efficient to make it. We have to keep costs down. We have to be efficient to survive."
Higgins pointed out that manufacturers have to keep prices low to appeal to consumers. "Generally, the price of brick hasn't changed over the years," he said. "People want to build with brick. People love brick, but people won't want to pay a lot for it."
Mass production in technologically advanced factories has been paramount in holding down prices. At one time, Higgins Brick needed 1,000 workers at five plants to manufacturer bricks by hand. Today, technology and 35 employees at a single plant produce the same number of bricks. At full capacity, the company can mass-produce 25,000 bricks per hour.
"When we're running at full speed, it's pretty impressive," Higgins said, noting that technology allows for less downtime and fewer workers, which saves money. "If you keep the production high, you can make the numbers."
To further hold down expenses, the company is able to produce 80 percent of its own energy by using natural gas to co-generate power with micro turbines.
"All the heat that comes from our turbines is exhausting into our kilns, which reduces the amount of natural gas needed for firing brick," Higgins said. "That alone saves the company upwards of $20,000 a month."
Other companies are also saving money with more efficient kiln technologies.
"Automation helps brick companies save money on labor costs during the manufacturing process. Hanson continues to work to make its kilns more efficient, including preheating firing zones and recycling heated air, in order to save on natural gas costs," Peters said. "As with any manufacturing industry today, gasoline prices — transportation costs — have had the biggest effect on the price of our product."
About the Author
Brett Martin is a freelance writer located in Shakopee, Minn. with several years of construction and writing experience.