Over time, the term “urban forestry” has become more common, and with that increased interest by the general public as to what is done with the trees that are removed from the urban environment. According to the USDA Forest Service, there is a tremendous amount of fiber removed each year, and over 30 million cubic yards of that material is classified as “unchipped logs.” The U.S. Department of Agriculture has calculated that if the unchipped logs were milled into lumber, those logs could produce between 3.2 to 4.4 billion board feet, the equivalent of about a third of the annual U.S. hardwood production. Although not all urban trees are suitable for milling, the number of trees that are suitable provide significant opportunity for increased profitability for tree service professionals.

The increased opportunity to mill trees removed by tree professionals comes by way of the modern portable band sawmill. A modern mill typically uses a thin-kerf blade, increasing the potential output of the source logs by up to 30 percent over a traditional circular sawmill. Because many band sawmills are portable, easy to set up, and can be operated by only one or two people, they can be towed to the work site to mill immediately after a tree is removed or set up at the shop for milling later if the log is to be seasoned first. Because of the their environment, urban trees may have nails, glass, wire or other items embedded in the trunk. Band sawmills are much safer than a chain saw or circular sawmill when a foreign object is hit. A band saw blade simply dulls rather than breaking and sending chain shot or blade fragments into the air as circular saws sometimes do, an important consideration when milling wood in an urban environment. This also means that band saws are safer for the operator that may have missed a foreign object during inspection.

Trees felled in the urban forest have spawned a successful business for Pacific Coast Lumber. Photo: Clayton Petree

Trees felled in the urban forest have spawned a successful business for Pacific Coast Lumber.
Photo: Clayton Petree

Tree professionals interested in milling urban trees for profit have several places they can source wood aside from trees removed by their own firm. For example, in San Luis Obispo, California, city arborist Ron Combs says they have developed a waste-free, or closed-loop, system that saves the city money and helps to improve the local economy by working with local businesses.

Since many cities, like San Luis Obispo, prefer not to spend money on tipping fees for tree disposal, and California has a legal mandate to divert trees from dumps, an agreement for a local tree service company to obtain trees removed by a municipality or as part of a tree service contract with the city can be a win-win situation.

A portable band saw helps Pacific Coast Lumber turn logs into lumber. Photo: Clayton Petree

A portable band saw helps Pacific Coast Lumber turn logs into lumber. Photo: Clayton Petree

Combs says that the smaller brush and branches are typically chipped and used for local projects. Excess chips or short solid wood are often given to citizens. “The wood turners association loves to pick through our piles,” he adds. The larger logs are “disposed of” by a local urban lumber service that either picks the logs up from the tree removal site or the city lot, or sometimes the city may deliver the logs to the log yard of Pacific Coast Lumber. Combs says this public/private partnership works well for the city. “We don’t pay tipping fees, we don’t waste time, and we save on fuel,” he explains. Due to the system, Combs says, “We try to plant with the future in mind. None of the city-generated fiber goes to a landfill, and each tree utilized from an urban forest reduces the need to harvest in other healthy forests.”

Don Seawater, one of the principals of Pacific Coast Lumber working with the city of San Luis Obispo, is widely regarded as an early pioneer of urban wood processing. He began milling in 1996 when he saw the potential for trees removed from municipalities, and he’s worked with CAL FIRE to test various mills and kilns for drying the resulting lumber. Seawater says, “Urban wood is often overlooked because of the relatively inconsistent nature of urban trees.” Urban trees may not be an ideal source of wood for a high-output commercial mill, however, Seawater saw opportunity because he knew the wood was suitable for the existing nonstandard and exotic material markets. The result today is really a combination of several businesses.

Pacific Coast Lumber has always offered arborist-related services and retains the ability to remove and transport trees to its log yard. However, Seawater explains, the company has moved toward emphasizing its milling and sales side. “I now prefer to contract with other local tree service outfits when possible,” he states. This practice generates more work for local tree service companies and allows Pacific Coast Lumber to concentrate on its milling and custom product side.

A bench built from "waste" wood. Photo: Clayton Petree

A bench built from “waste” wood. Photo: Clayton Petree

Once trees are in the Pacific Coast log yard from either a private source or from the city, Seawater and his crew use a portable band saw to mill the logs into lumber. About half of the lumber produced is sold as general lumber, with the other half used for the company’s growing list of manufactured products, or for customized projects produced for customers. With a licensed architect on staff, Pacific Coast is able to custom design, build and install nearly any project a person may desire. Everything from Adirondack furniture kits the user assembles at home to full-blown retreat structures with live edge siding, doors and windows are available — all manufactured with recovered urban wood.

Seawater sums up the potential for other tree professionals looking for a source: “Using a private sawyer as San Luis Obispo does keeps everything simple for the department. The jurisdiction will save time, money on tipping fees or the cost to chip, labor and fuel. A public/private partnership also stimulates local business that pays local taxes and will make a wide variety of product available for the general public or for the jurisdiction.”

In Reno, Nevada, Darin Bue, owner of Los Verdes Arborists, says he considers his Wood-Mizer portable band sawmill to be an important part of his firm’s future operations. “The idea of using the material we deal with as a resource has always appealed to me,” he comments.

Bue has found that cities and other jurisdictions are often interested in working with arborist firms on utilizing portable mills for environmental reasons. The city of Reno, he says, has participated in several experimental salvage operations with Los Verdes Arborists, researching how best to turn the cottonwood, walnut, elm, maple and sycamore logs removed in the course of the city’s care of the urban forest into lumber. The Los Verdes portable mill was also used on-site at Sierra Nevada College in Incline Village, Nev., to turn trees removed during construction into lumber, which was then used to build on the site the trees had been removed from. The buildings were later awarded platinum status by the U.S. Green Building Council. Platinum status means the building has the highest level of environmental design and, at the time, had been awarded to only a few dozen buildings in the U.S.

A picnic table constructed of wood from the urban forest. Photo: Clayton Petree

A picnic table constructed of wood from the urban forest. Photo: Clayton Petree

Tree service professionals across the nation are at the forefront of an environmental revolution as the importance of the urban forest, especially in terms of carbon removal and sequestration, comes to be recognized. The portable band sawmill has become an invaluable tool for many firms, allowing tree professionals to participate profitably in that revolution through the production of high-value end products from a resource once considered to be waste.