Where There’s a Wood, There’s a Way
By Gregory Burnshaw

When dismantling the historic timber-framed barns and shelters of the past, it’s common to discover a variety of different wood timbers making up the structural frame. When function – and not aesthetics – was invariably the priority, timbers easily accessible and indigenous to the immediate area were the most likely candidates. Poplar, maple, and beech might do the job – but so would a chestnut (considered extinct) or a walnut timber, too. Barn restorers and reclaimed flooring manufacturers would consider these a treasured find.

Today, accessibility is less of an issue. We have the means to ship timber from close or far, which broadens our menu of choices. And single species timber frames are standard – although not in every case. Our choices, if not dictated by engineering requirements for strength or length, are typically based more on the color, the stability, and the cost.

In general, the trees from which the timber is extracted come in two categories; deciduous and coniferous. Deciduous trees are identifiable because they lose their leaves annually. Ash and maple fall into this category but are generally not chosen for timbers for various reasons. Other hardwoods favored by timber framers, like the oaks and cherry are very strong and attractive but difficult to find in high quality and suitable sizes. All woods that are hard are more susceptible to “checking” as they dry. Checking is the cracking that forms along the vertical grain of the timber while it dries. Although all wood checks to a degree, it is not uncommon for a hardwood to form a check deep and wide enough to insert the tips of your fingers. Checking does not necessarily affect the structural integrity of the timber – especially when care is taken to maintain the heart (center where the growth rings begin) within the timber; this is referred to as boxed heart. As a rule of thumb, it takes approximately one year to air dry one inch of timber – so, expect an occasional “crack” in the middle of the night during the first four to six years of enjoying your timber framed home.

Coniferous trees are the ones with pinecones and needles. Douglas fir, hemlock, white and yellow pine, heart pine, spruce, cedar and others are all viable timber frame choices. They are generally more plentiful, check less, and emit a pleasant scent for years. Considered “softwoods”, the name should not imply weakness. Douglas fir, for instance, is harvested from both sides of the Cascade Mountains in the Pacific Northwest. It is very strong, stable and is available in long lengths – easily up to 50 feet. It comes in a variety of quality levels and appearance grades. Its color varies from warm pinks, oranges, and rusty reds. Eastern white pine, very consistent in color and just as stable, is about half its raw material cost – making it a popular favorite. Southern pine, with its beautiful olive and butter-colored grain, is chosen when strength is required but costs are a factor. It is on harder side of the scale for soft woods and can be unruly, so kiln drying in necessary to insure its stability. On another positive note, southern pine is a fast growing species, plantation grown – and highly managed – attractive to those of us who are attentive to ecological impact. 

Most timber suppliers are connected with forest management and replenishment programs, but if you’re conscience pulls you in the conservationist direction, recycled and reclaimed timbers offer an excellent alternative. Upon request, timbers that have enjoyed a previous life as a factory, a bridge, or a warehouse can be reused in your home or project. Riddled with character marks; bolt holes, rust stains, nail pocks, etc, reclaimed timbers can be used as is or re-milled to give it a facelift and expose it’s lost inner beauty. Its recovery generally adds steps to the procurement process which increases it’s cost over newly harvested timbers, but the results can be dramatic and unique. A recycled frame that ended up in Steamboat Springs, Colorado, began as a train trestle. Submerged for years, it was recovered from the depths of the Great Salt Lake in Utah.

Gregory Burnshaw is a timber-frame furniture builder and works for Woodhouse Timber Frame Homes. You can contact him at burnshaw@timberframe1.com.