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The Difference Between Timber Framing and Post and Beam

What is the difference between timber framing and post and beam? Many people have a hard time distinguishing between the two methods of building with heavy timbers.  Primarily the difference is with the connections.

Both timber frame and post and beam construction utilize durable heavy timbers, as opposed to dimensional lumber that can be purchased from any lumber yard. Dimensional lumber has been cut to pre-defined, standard sizes such as 2x4’s, etc. The heavy timbers used in both post and beam and timber frame are much larger and generally remain exposed in the building, creating an honest expression of the structure and giving it a sturdy appearance. When it is designed and constructed with care and skill, the beauty of the frame itself creates the artistic character of the building. The organic beauty of wood is celebrated in the exposed timberwork whether post and beam or timber frame.

Timber Frame Pergola Kit

Similarities of Post and Beam and Timber Frame

Both timber framing and post and beam are construction methods in which the structural frame is self-supporting and carries the weight of the house. This means that for both methods interior load-bearing walls are unnecessary, which makes possible large open interior spaces and high vaulted ceilings. When the frame is left exposed (as it usually is), an organic beauty enhances the building. Both types of frames are usually prefabricated in a sheltered environment, then labeled and delivered to the job site where they can be quickly raised.

Both timber framing and post and beam are examples of sustainable construction. Quite often the wood in these frames is reused from existing structures, or harvested from standing dead forests. And because of how the timbers are assembled, they can be disassembled and repurposed in a future building.

Differences between Post and Beam and Timber Frame

The main difference between these two systems is the way the timbers are joined. Timber framing dates back to medieval times, and there are structures built then that are still standing today. Timber frames utilize traditional joinery such as mortise and tenons. They incorporate very few metal parts - mainly hidden structural screws where absolutely necessary, such as securing rafters to a ridge.  In post and beam buildings the timbers are usually connected with metal fasteners and connectors, which can either be hidden or decorative.

Post and beam usually use half-lap joinery. The fasteners securing the timbers may be hidden within connections or exposed and decorative. Timber Frame uses mortise and tenons, scarf joints, spline joints, and other joinery secured with wooden pegs. The cost of skilled labor to cut and fit the joints is much higher in a timber frame home than a post and beam.  However, the metal connectors in a post and beam building can be a  significant cost factor. 

The raising (erecting)  process is different for a timber frame than for a post and beam building. The sections of the timber frame are assembled on the ground and then erected, individually, until the entire framework is completed. With post & beam construction, the frame is built from the ground up, with the parts being added on top of each other. 

Timber Framing Characteristics

  • The traditional joinery in a timber frame is complex and sometimes must be engineered to deal with loads generated at different locations within a building. A timber frame structure relies on tight-fitting joinery, the integrity of the materials, and critical geometry to create a self-supporting building.

  • The joinery for a timber frame requires precision and must be done by trained craftsmen. Lately, automation has been developed to cut the joinery using CNC (Computer Numeric Control) milling machines.
  • Timber frames are designed and built as stand-alone structures without using any additional framed support.
  • The frame is usually left exposed, so the structure itself is a big determinant of the style of the building.
  • Timber frames are held together using wood pegs or wedges. The pegs are driven into slightly misaligned holes in the parts of a joint, which allow the timber framers to draw the parts together to create stable connections. 

Post and Beam Characteristics

  • Post and Beam frames can be both structural and ornamental.  The metal connectors can be completely hidden within the frame or exposed and decorative.

  • Post and Beam structures allow the building designer a great deal of freedom in developing both interior and exterior space.
  • Post and Beam look similar to timber frame since the size of the members is alike. Labor cost is less since it does not utilize complex joinery.
  • In the erection of a Post and Beam building, the frame, wall, and roof components are assembled in succession.
  • Post and beam frames are usually used in conjunction with additional structural elements such as shear panels and infill framing to create a secure building.
Post and Beam Framing

Post and Beam Framing

Post and Beam Connection with T-Rex

Post and Beam Connection with T-Rex

Advantages of Timber Frame

  • Often more artistic and elegant than post and beam.

  •  Traditional wood-to-wood joinery, if kept dry, can last for generations.
  • Traditional wood joinery is flexible, meaning it can deflect and move a bit under loads without failing

Disadvantages of Timber Frame

  • Traditional joinery requires skilled craftsmen to fabricate. This results in higher labor costs.

    If timber sizes are increased during engineering to accommodate joinery, the timber costs also increase.

Advantages of Post and Beam

  • Post and Beam frames can be both structural and ornamental.  The metal connectors can be completely hidden within the frame or exposed and decorative.

Disadvantages of Timber Frame

  • If moisture condenses on steel surfaces, they can rust and cause the adjacent wood to decay. If the metal connector plates are complex, these elements can markedly increase the material costs.   Disparate materials such as metal connectors and wood beams can work loose over time.


Timber Connections

Truss Plate and Post Closeup

Timber Connections

Timber framing is a method used by our forefathers and their ancestors, who brought with them the skills used in Europe and other countries for centuries. Using traditional wooden joinery to piece together large, usually squared timbers, the connections are carved out to fit together like a complex puzzle.  An example of such a connection is a mortise and tenon joint. When the connection is made, it is usually with wooden pegs because the use of metal is not practiced with timber framing; this type of framing requires a high level of skill and can be very time consuming.  There are schools that offer courses to teach these methods such as the the ones found here.

Post and Beam, in contrast to timber framing, has a distinct look that provides a more industrial appeal.  This method of framing also uses heavy timbers, however the connections are much less complicated; fasteners in the form of metal screws, bolts and plates are used to connect the timber pieces.  The simpler connection usually requires less time to craft.  A business like Simpson Strong Tie offers plates and bracing that provide a functional solution in their Architectural Connector product line.

Alternative Framing System: T-Rex Connector

One company to offer an alternative to both framing with mortise and tenon,  and framing with angle/corner bracing is Connecticut Post and Beam, with their connector.

This extruded aluminum connector is mostly hidden and no special skills are required. Fine Homebuilding called this method "21st Century Post and Beam,” in a recent article in one of their Spring publications, "Building Sheds".  Due to their inquiring customers, Connecticut Post & Beam created a simple connection that balanced the art of timber framing with the industrialization of post and beam.  These customers were not interested in spending the time and utilizing the skills needed for traditional methods, nor did they want to use the big metal plates and corner bracing common in post and beam construction.  Framing with T-REX presents a viable alternative with a minimal metal look that is not only engineer-approved, but cost effective as well.  Plans, connectors and custom tooling are available at Connecticut Post & Beam.

t-rex connector in the shop

Timber framing and post and beam construction both demand tight, well-crafted joints, but post and beam fabrication is usually less labor-intensive. It is often very hard to distinguish between a timber frame and a well-crafted post and beam structure. The appreciation for traditional craftsmanship versus cost are determining factors in deciding which approach to use. Timber framing can add 25% over the cost of a stick-built home. Timber framing can cost 10-15% more than post and beam construction. Post and beam construction and timber framing both celebrate the beauty of wood, but post and beam breaks from pure traditional joinery.

In conclusion, building with larger timbers encourages personal design choices, showcasing either a handmade and rustic look, or a sleek and more modern appearance.

4 thoughts on “The Difference Between Timber Framing and Post and Beam”

  1. Hey Brice,

    Paul Freeman from Brooks Post & Beam here. We could very well be the oldest timber framing company in the country. Our founder built his first timber frame in 1968 and gradually grew the business from timber frame restoration to cutting of new frames, incorporating in the ’80’s as a sub-s corporation.

    We occasionally employ steel in our frames to meet modern codes or simply to save a client significant labor expense on joinery that would mostly be invisible and under-appreciated by laymen. However 99% of our joints are mortise and tenon, pocketed timbers, or mortise and spline joinery.

    We are timber framers, I am a past president of the Timber Framer’s Business Council and board member of the Timber Framer’s Guild. My company name is Brooks “Post & Beam”. When we started, “timber-framing” was not a classification for construction, “Post & Beam” was a broader description and over the years timber framing has grown to describe the craft of building timber frames in a traditional manner. Personally I define timber framing as a subset of post & beam. In other words timber frames are post & beam structures but not all post & beam structures are timber frames.

    It should be mentioned that in the larger commercial environment heavy timber construction is used as a general description of any construction using timbers, glulams, and other large manufactured structural wood products.

    I recognize that many timber framers describe post & beam as you have here. However, if you were to poll the general population I think you’ll find that post and beam is the common description of heavy timber framed structures. It is a phrase easily recognized and one could argue is a de facto definition.

    I have been following the development of your website over the last few years and you have done a great job. Ed Levin and I developed TimberCAD many years ago and invested untold hours in that venture not for fame or fortune but simply out of a passion to develop a tool used in the development of timber framing. I see your effort as a similar outlet of passion for the trade and a tool to expand the timber frame industry. Good Work and Thank You!

    1. Thanks for your comments and thoughts Paul.
      I agree with you about the a general polling of folks and their interpretation of timber framing and post and beam structures. I have also found people who consider a timber frame a log home, as you know education is the key.
      For me I am happy if folks use timbers instead of LVL and glulams to solve their structural needs. I actually used TimberCAD for a little while back in the beginning of my design career. Thanks for all you do for the industry.

  2. Thanks for the clarification. I am planning on building a Timber Frame on my property in Williams Az. I am a Blacksmith and not only am I going to build the home but I have started making the Slicks and chisels to do it. I was always confused by the difference between “Post and Beam” and “Timber Framing” I have been thinking about all the joinery and am a bit intimidated by the whole process. I am working on the drawings for the Building permit and was considering using steel in a number of places throughout the structure. Some for the decorative aspect but also structurally as well. I bought and downloaded your 20′ x 20′ shed drawings. They are a great asset for me as I do the drawings for the house. I’ll build the shed and probably modify it some this spring and it will be used as the wood shop initially then the Blacksmth shop later on. The process should help me determine if I am out of my mind to think I could build the house as a Timber Frame. I don’t see the need to do all the joinery if it is going to be buried when the simplest solution is to use steel plates and thru-bolts. The joinery that will be exposed is what i really want to excentuate. It is very similar to the work that I do in iron. You have to have dreams. Thanks for all the information . Great website. Tim Cisneros http://www.theforgeworks.com

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