Is brick a good option for siding? How green is it?
by Miriam Landman, 01/19/08
Miriam Landman, owner of M. Landman Communications & Consulting, is a Northern California–based green building advisor and environmental writer. She is a LEED Accredited Professional, and has a master's degree in Urban and Environmental Policy from Tufts University.
Question: How does brick compare to other siding choices? I’m trying to design a green home and I like the look of brick.
– Ken Yaber, Bonneau, SC
Answer: The short answer is: It depends. Some bricks are greener than others. The greenest options are salvaged bricks, locally manufactured bricks with high recycled content, and adobe bricks.
Bricks do have several green attributes. They are durable, low maintenance (no painting required), fireproof, insect resistant and water resistant, and they provide thermal mass (which means they hold heat, a feature that is most helpful in regions with chilly nights or cold winters). Their small unit size also helps reduce construction scrap, and any extra brick can be used in landscaping.
The main problem with bricks is the amount of energy required to make them. The production of fired clay bricks (the type most commonly used) involves heating the bricks in kilns at very high temperatures, an energy-intensive process. (According to BuildingGreen’s GreenSpec guide, the embodied energy is 14,000 Btu per standard brick.)
If you’re going to use brick as a siding veneer, try to use salvaged or reused brick. For structural uses, salvaged brick should be tested and approved by a structural engineer. Using old bricks can create a nice historic look. With so much brick used on homes in South Carolina, there should be plenty of places near you to find used bricks. For example, Old House Salvage in Piedmont, South Carolina, has antique brick. Check the Building Materials Reuse Association’s online directory for other facilities in your area.
Your second best option is to use locally produced bricks made with recycled industrial waste. Fortunately, this material is readily available in your region. North Carolina–based Green Leaf Brick makes bricks out of 100 percent recycled materials acquired within 500 miles of their manufacturing plant. Green Leaf’s website provides a lot of information about the bricks’ green attributes. Cunningham Brick, based in Lexington, North Carolina, also uses recycled industrial waste material in its bricks; different colors have different percentages of recycled content (ranging from 7.5 to 83 percent recycled). The company's website lists multiple distributors in South Carolina.
Another alternative is to use low-fire or air-cured stabilized earth masonry (adobe brick), which has much lower embodied energy than standard fired-clay bricks (approximately 3,700 Btu per adobe brick). However, this material is better suited for homes in regions with a dry climate, such as the Southwest.
When building with brick, you can also reduce your environmental impact by using low-VOC sealers (such as AFM Safecoat's WaterShield or Penetrating WaterStop) and recycled-content mortar. Conventional mortar usually contains a lot of portland cement, which has high embodied energy. Mortar products are available that substitute industrial and agricultural waste products, such as fly ash, ground blast-furnace slag or rice-hull ash, for some of the portland cement. However, there is some controversy about whether it’s safe to incorporate potentially hazardous industrial byproducts like fly ash into construction materials.
Other green siding options include fiber cement siding, Forest Stewardship Council (FSC) certified sustainably harvested wood, natural resin–based exterior panels made of recycled materials (such as PaperStone Rainscreen XP), engineered/composition hardboard or OSB (oriented strand board), or rammed earth and stucco.
For more information:
See the Environmental Building News article “Residential Siding Options,” for a green comparison of siding options.
For more information on green siding for your home, read GreenHomeGuide’s Ask A Pro articles:
“What’s the Best Affordable Sustainable Siding Option?” by Carl Seville
“Which is Greener: Fiber Cement or Vinyl Siding?” by Connie McCullah
GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S.
On January 23, 2008, Jason Stone wrote:
Great article. I’d also note that perforated or cellular brick (with holes in the center) require less material to make. Also, in St. Louis the brick has been around for over a hundred years, so we like to think that the embodied energy is significantly lessened over the extreme timeline of the life of brick.
You also might consider looking into Endicott Modular Thin Brick. It’s thin sliced brick installed in a steel frame and then mortared in place. It’s not structural, but it essentially the real thing both in appearance and touch.
Both can contribute to the point line in the NAHB GBI guidelines - “Use products that contain fewer resources than traditional products.”
Jason
On January 24, 2008, Scott wrote:
I have a brink patio that needs a sealer from time to time. I’m looking for a green solution/alternative to Thompsons’ Waterseal. I could forego sealing the brick but then it fads, looks dull, and becomes a haven for mold and fungus in the South Florida humidity.
Any thoughts or suggestions?
On January 24, 2008, Miriam Landman wrote:
Jason,
Thanks for adding these great suggestions!
On January 24, 2008, Miriam Landman wrote:
Scott,
Check out the links above to AFM sealers (WaterShield and Penetrating Waterstop), in the second to last paragraph of the article.
On April 22, 2008, Stephen Sears, Brick Industry Association in Resto wrote:
Hello:
As the Senior Director of Marketing and Communications at the Brick Industry Association in Reston, VA, I was very pleased to come across this article and your response. However, I’d like to clarify some of the points made in your column.
1) The amount of energy required to manufacture brick is less than you think.
While brick does require energy to turn clay and shale into brick as we know it, the 14,000 Btu per standard brick that was cited in the column is based on data circa 1970. The current embodied energy average for U.S. manufacturers is about 1239 Btu per pound of brick or around 4300 Btu per standard brick.
2) Please be mindful when using salvaged brick as a siding veneer.
Using salvaged brick is a wonderful way to add instant character to a project, but one should take care when using salvaged brick as a residential siding material - especially if that brick was previously installed on an interior wall. Why? The answer is that salvaged brick was not manufactured to the same specifications as modern clay brick. Additionally, most salvaged brick was not used in a single-wythe brick veneer application. So, if a homeowner plans to use salvaged brick, please make sure that it is tested to meet today’s standards.
3) You can reduce your environmental impact even further by not using any sealers.
We actually do not recommend the application of any water sealers at all. Brick was never intended to be a waterproof material, and modern construction practices (e.g. cavity wall construction, flashing and weep holes) purposely allow moisture to flow through the brick wall. In a paving application, the key is to ensure that the base below the pavers allows for water to drain. Additionally, if one finds that sealers are necessary to prevent their pavers from fading, then the paver they have is most likely a concrete paver - not an authentic clay brick.
In sum, we believe that clay brick is the most sustainable green building material made. It is made from natural materials, requires very little maintenance (e.g. painting, power-washing, etc.,) lasts an extremely long time and is highly recyclable. Clay brick is also highly sought after as a salvaged material - a factor that is not the case with most other popular siding materials.
If you would like to find out more information brick, please visit our industry’s website at gobrick.com. And if you want to learn about clay pavers, go to http://www.gobrick.com/pavers.
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