Utilizing Urban Timber

Originally published in Oak News & Notes, Vol. 19, No. 1

The urban forest provides municipalities, homeowners, business owners, and visitors with many wonderful benefits, but it can also present unique problems. Urban trees may reach proportions matching those found in the wild and when grown in tight spaces, as is common in cities, they can be very difficult to remove when the time comes. The issue then becomes what to do with all of the wood? Many cities are not equipped to handle large quantities of wood.

This is a real problem many US cities are now facing with the advancement of the Emerald Ash Borer (Agrilis planipennis), which is wiping out thousands of acres of urban and rural ash trees (Fraxinus sp.), and the

Author milling a salvaged urban log (Q. palustris)

new threat of Thousand Cankers disease threatening to decimate black walnut (Juglans nigra) populations. Now, Rapid White Oak Mortality (see Oak News & Notes, Vol. 19, No. 1, pp.4-5) is threatening tens of thousands of white oaks. Red oaks (section Lobatae) have already been hurt by Oak Wilt and other ailments such as bacterial leaf scorch and Hypoxylon—which usually finishes stressed trees off. All of these issues, when  combined, could mean tens of thousands of dead and dying trees (realistically many more than that) will need to be dealt with. New construction (often called bulldozer blight) also kills numerous trees annually by changing grades or compacting root zones of existing trees. Much of the wood can be chipped and used for mulch, if chipped finely enough, or used as a source for firewood or biofuel as a coal substitute. But what about the logs? Many times these are too large to chip and most municipalities are not able to sell these logs. A good alternative is to use them for lumber. However, most commercial sawmills will not accept urban timber as they are concerned these logs will contain nails, wire, etc. and often they do.

Red cedar (Juniperus virginiana) with black oak (Q. velutina) Beautiful coloration in boards of a salvaged urban log - pin oak (Q. palustris) 1 × 8 lumber

Fortunately, a few independent mill operators can be swayed to take a chance on a nice urban log. Occasionally, they are willing to take partial trades of the milled lumber in exchange for cheaper rates. Recently, independent “urban” timber companies have begun springing up around the country. These mills

Waste pieces I use for trim

specialize in urban lumber and many even retail this lumber to home builders and wood workers. They will often offer hard-to-find lumber like Zelkova, Gymnocladus, Morus, Platanus, etc. These independent mills are usually portable and are either band, blade, or occasionally chain saw mills. The great thing about these mills, besides the portability, is that many times you can hire a mill operator to mill one log or multiple logs. Some communities have seen the need to utilize urban timber and have begun purchasing portable mills of their own. Band and chainsaw operated mills are great for slabbing large pieces of wood and blade mills are great for dimensional lumber. The lumber can be sticker stacked outdoors and covered, then used later (usually about a year depending on species) or a kiln can be made to dry lumber quicker (a few weeks to a month). Some enterprising communities have also begun selling lumber as a way to supplement budgets. Of course local regulations need to be consulted, but this can be a great way to handle urban timber and boost a sagging budget. Arboreta and gardens should also look into milling lost trees as they could certainly have unique species, not often found. This wood can be used for benches, plaques, artwork, etc., and is a great way to utilize urban wood. An internet search can be helpful in finding independent mill operators in your area, or you can contact your local forester, and they should be able to put you in touch with an operator who will work with you. 

Quarter-sawn Q. velutina Sticker-stacked pile
More images from the sawmill
Salvaged urban lumber in Kansas City, Missouri. Photo: © Alan Branhagen