What is the difference between Post & Beam and Timber Frame?
by Tedd Benson

Joinery
Joinery defines the major difference between timber framed structures and others. Without joinery, the structure is made with posts and beams but it is not a timber frame. The craft of timber framing is in the shaping and assembling of the joints. The person who practices this art is a joiner.

Most timber joints are variations on the simple mortise and tenon: a tongue on one timber inserted into a slot in the other. Mortise and tenon joints are generally locked with round pegs which are driven through holes drilled through both parts of the joint. The other broad category of joints used in timber frames consists of joints whose pieces lap into one another. Some of these joints rely entirely on their angular shapes and the weight of the timbers to lock. Others are secured by driving a wedge through mating notches. Japanese temple builders developed some of the most sophisticated joinery and still practice it under well established guidelines.

The American housing industry is one of the world's marvels. Five hundred years ago, there was virtually no housing stock on the North American continent. Today, three hundred million people are sheltered there against an often hostile environment. Housing has traditionally employed more Americans than any other manufacturing concern.

One of the most intriguing recent developments within the industry has been the rapidly expanding interest in timber framed homes. These homes have an exposed inner structure of heavy wooden posts and timbers handcrafted to interlock and connect without metal fasteners. They are not a recent American invention, however.

Most of the world's traditional architectural styles were founded in timber framed structures. These construction methods evolved through the centuries as the skills and aspirations of the builders increased. Indeed, the master timber framers of old were so confident in their established formula that they used the same styles to construct peasants' cottages, magnificent cathedrals and everything in between. This ancient building technology still permits variations that are as suitable for 20th century building as for 15th century building.

Timber frames have always been adapted to the materials and methods available. As surely as timber limitations influenced building design, so did timber abundance. When the colonists came to North America, they left behind a Europe denuded of timber resources. They found themselves in the midst of virgin forests with trees long enough to run the length of most buildings. Although they did not immediately devise new techniques to take full advantage of this great resource, early Americans eventually developed a unique building style that featured long timbers for posts, plates, rafters and tie beams. These buildings were stronger, simpler to construct and used less timber than their old world counterparts.

Since labor was in extremely short supply in the colonies, the new American builders also eliminated most of the time consuming embellishments from the frames. Although the first colonists came from England, others soon followed from France, Germany, Holland and Scandinavia. They all brought different traditions, opinions and information about building methods that were tossed into the melting pot and gently affected the state of the building art. Most of the timber framing done in North America could not be said to have originated from any specific country. It was a peculiarly American blend.

The immense amount of precious labor required to build a timber framed house in colonial times demanded, first, that the building have a long life and second, that the job be done well the first time so it would not have to be repeated. It was simply a practical way of thinking which pervaded all life in those days. One of the oldest surviving timber framed homes in America, the Fairbanks House, dates from soon after the colonists' arrival and is a fine example of the early efforts.

Timber frame architecture in this country is classic because it accurately reflects the spirit of the age from which it emerged and the people who gave it birth. The early settlers didn't design with personal whim or passing fancy -- these were people whose hopes rested in future generations.

The Present
Most American homes are no longer built for great-grandchildren inhabitants.  American homes tend to be built with re-sale in mind. The demise of timber framing as the dominant building system in America was coincident with the rise of industrial capacity. Labor has always been a limiting resource in America. The development of huge sawmills and nail factories meant that homes could be built with balloon framing systems much faster than with labor-intensive timber framing. The virgin forests had been depleted at the same time, making the large trees required in timber framing harder to find.

Builders who use traditional joinery and framing systems are driven by a pursuit of values and standards set centuries ago. They build homes that are worthy legacies, homes with classic stature and the ability to withstand the powerful forces of time and change. They are not building timber frames out of simple nostalgia for days gone by. Building with heavy timbers can still be both sensible and practical.

Perhaps the most important contribution of the timber frame to modern building technology is the support it provides for an extremely effective insulating system. With a strong and attractive timber frame bearing all of the building loads, the insulation and the frame can be completely separate systems. Mindful of this advantage, timber framers moved the insulating wall to the outside of the frame and reduced the structural elements of the enclosure system. This made construction easier and improved the home's heating characteristics. Most American timber framers now use a product called stresskin panels, which is a core of rigid foam insulation sandwiched between interior and exterior sheathing. The panels do not contain any frame members so the insulation is uninterrupted. By using these panels, timber frame homes have gained a reputation for excellent energy performance.

From Maine to California and from Alaska to Florida, the craft of timber framing is enjoying a new life. Posts, girts, braces and summer beams are being shaped again by modern day joiners revelling in the rich experience of working with timbers. The finely honed edges of chisels and slicks are meeting timbers much as they did 200 years ago. The art of joinery is advancing again through interaction among dedicated joiners. People are attracted to the old fashioned fundamentals of fine timber framing: skills of the hand, basic building materials, a few simple tools and heavy portions of dedication, hard work, patience and practical intelligence. The modern energy-conserving, comfortable and beautiful timber frame house is an intriguing and exciting mix of an ancient building method and modern technology.


Reprinted with permission from an article entitled "Joinery" by Tedd Benson.