Timber Frame Joints: Connecting the Past and Present

We all appreciate a piece of quality craftsmanship and yet, so often our building construction prioritizes efficiency and low costs over beauty and quality. Before the days of booming population centers and cheap housing, buildings were hand-crafted with special attention to quality and aesthetic appeal. The use of timber framing and timber frame joints was popular in years past but has since been replaced by cheaper and more efficient building methods. At Lancaster County Backyard, we are reviving this time-tested construction method with our patios, pergolas, and gazebos. Learn more about timber frame construction with this video below:

As timber frame construction became less popular, some of the building methods used were forgotten. A key skill that many builders lost in the process was the art of crafting timber frame joints. Instead of relying on nails and screws, builders in times past created joints out of the wood itself by hewing the wood to fit snugly together. The result was a joint that was both beautiful and durable. Today, builders prioritizing quality and beauty over efficiency are reviving this lost art. Here are some of the most common timber frame joints both from the past and those that are being used once again.

Timber Frame Joints: Mortise and Tenon

The most common of the timber frame joints is the mortise and tenon joint. This joining technique has been used for thousands of years as a superior joining technique for wood and other materials. Instead of using metal fasteners that can rust and break over time, this technique uses the wood itself to join the two pieces of wood. 

A mortise and tenon joint is made of two pieces of wood, with the mortise being the hole in the one piece of wood and the tenon being the piece of wood that is received into the mortise. For years, the mortise and tenon joint has been used in a variety of construction applications like houses, barns, and other outdoor structures.

While the mortise and tenon joint has long been considered a better way of joining materials, it is also incredibly time-consuming. Up until recently, each mortise had to be cut out by hand and to exact measurements. The tenon also had to be cut by hand to a precise measurement that would allow the mortise and tenon to fit together perfectly. Now, thanks to large machinery and specialized automated tools, the mortise and tenon joint can be cut out in a fraction of the time and to even more accurate measurements. Here are several common variations of the mortise and tenon joint.

Shouldered Mortise and Tenon

The shouldered mortise and tenon joint is most commonly used in the main joints of the carrying beams on a Timber Frame structure. The carrying beams are shouldered one inch onto posts using a tapered cut. These joints are held in place by one inch pegs. The combination of the beams being shouldered onto the posts and the one inch pegs create a super strong joint.

Brace Mortise and Tenon

A brace mortise and tenon joint is typically used to support two pieces of wood that are connected at a 90 degree angle. The brace runs diagonally across the corner of the two pieces of wood, adding support to the frame or truss. The joint itself is a typical mortise and tenon joint, with the tenon being inserted into the mortise, and fastened by a wooden peg through both the mortise and tenon.  It’s very common to see these braces anywhere mortise and tenon framing has been used, often in support of a post and beam connection or truss structure.

King Post with Mortise and Tenon

It’s quite common to see a king post in a roof truss anywhere mortise and tenon framing is being used. Trusses are typically built in a triangular shape with additional support framing inside the triangle to give it strength. A king post is a piece of framing that connects at the peak of the triangle and runs vertically down, and connects to the bottom horizontal part of the truss.

The joints used to connect the king post with the peak of the triangle can be somewhat complex when using mortise and tenon joints, since it involves connecting three separate pieces of wood, instead of two. The top of the king post will have two mortise holes where the tenons of the connecting pieces will join.

Timber Frame Joints: Other Common Joints

Dovetail Joint 

Another timber frame joint that is fairly common is the dovetail joint. This type of joint is often used in furniture construction and is known for its unique beauty. It differs from other mortise and tenon framing in that there is no peg or other form of securing the joint. It relies on wedging the two pieces of wood together in a finely crafted dovetail shape, which becomes quite strong once joined together.

Wedged Scarf Joint

When looking at older timber frame structures, you may notice some of the longer floor joist beams are made up of two pieces and are bonded by a unique diagonal joint. This is likely some sort of scarf joint.

This joint style is often used to create a single long beam out of two pieces. The joint itself is made by cutting the ends of two pieces of wood at an angle in an interlocking pattern so they stay in place when fitted together. The joint is designed to fit loosely, and becomes tight when two wedges are hammered into the joint, creating a strong bond that effectively makes the two pieces into one beam. Check out this page for an example of the wedged scarf joint.

Timber Frame Joints: Conclusion

At Lancaster County Backyards, we are proud to bring back the art of crafting fine timber frame joints and building high-quality, durable structures at a reasonable price. If you’re interested in learning more about our buildings or want to see the products we sell, feel free to reach out!

Contact us for more information or request a free quote for your pavilion today!