Are you just getting started learning about timber frames? That’s great, this page has been designed especially with you in mind.
We’ve gathered resources throughout our website and elsewhere on the internet that we feel will help you get started in learning about or getting a timber frame. One of our goals is to help you make the best decision in regards to your timber frame construction project to make sure it goes as smoothly as possible for you.
Other Site Resources
Timber Frame Associations
So, What is a Timber Frame?
Timber framing has a long history throughout the world as a traditional building practice. With timber framing, heavy, large timbers frame the structure instead of more slender dimensional lumber (for example, 2 x 6’s.). One of the most distinctive characteristics of a timber frame is the unique joinery that holds the timbers together. The ends of timbers are carved out so that they fit together like pieces of a puzzle. A hole is drilled through both timbers to be joined, and a wooden peg is forced into them to hold the joint together. There are many types of joints used in timber framing. Some of the common joints are mortise and tenon, lap joint dovetail, tying joint, and scarf joint.
In the 20th century, the demand grew for cheap, quickly built housing, and dimensional lumber edged out timber framing as the standard building practice. After a long dormancy, the timber frame revival began in the United States in the 1970s. Skilled craftsmen have brought back the old methods of timber framing while incorporating the advantages of our modern technology. The timber frame revival has spread throughout the world and today there are active timber framing communities in many countries, including Canada, France, Germany, the United Kingdom, Australia, Denmark, the United States, and Japan.
Because timber-frame construction is so strong, load-bearing walls through the middle of the house are usually unnecessary. This allows for flexible and open room configurations. Yet even with high-volume, open spaces, the frame unifies the spaces and the warmth of the wood and the joinery humanizes it and makes it more intimate. The walls of the structure are typically erected on the outside of the timber frame, which leaves the timbers beautifully exposed inside the house. The exterior of timber frames can be clad with any typical building material, so your timber home can take on many different architectural styles and fit into any neighborhood.
What are the differences between timber framing and conventionally built homes, log homes, and post and beam houses?
Timber homes are complete structures made of heavy timber vertical posts supporting horizontal beams. These form cross-sections called bents, and multiple bents create bays. Other members such as knee braces and struts provide support to the frame.
Conventionally built homes (sometimes referred to as stick-built) are framed with smaller dimensional lumber that is readily available at lumber yards— in preset sizes such as 2x4, 2x6, etc. Because the materials are smaller, load-bearing walls must be incorporated into the design to support the structure.
Log homes are built of logs stacked horizontally, which structurally form the walls. Log homes tend to have a horizontal profile formed by these stacked elements. Log homes are easily identifiable from the outside because the logs are left exposed.
Post and Beam
Post and beam construction uses heavy timbers much like timber framing. The timbers may be round logs or milled square timber. What makes the different from timber framing is they use metal fasteners, which are either hidden or exposed on the face of the beams.
Today’s designs have become more intricate and code requirements have become more strict. That has sometimes caused a blurring of the lines between these different types of construction. For example, there can be some joints in a timber frame that require engineered connectors. These connectors can be hidden inside the joint, preserving the traditional timber frame appearance while taking advantage of modern technology. Also, hybrid structures are common, in which the less important parts of a building are conventionally built for cost savings, and the more public spaces are constructed with the dramatic beauty of the timber frame.
What are the Benefits of Timber Framing?
The exposed timbers, complex joinery, and open floor plans give timber frame homes an aesthetic unmatched by any other type of construction. In addition, timber structures boast strength and durability not seen in conventionally built homes. Since the large timbers are more resistant to burning completely through in the case of a fire than the smaller lumber that makes up conventional building structures, they provide more structural integrity in the unfortunate event of fire damage. And a timber home creates the opportunity to make a bold design statement, as there are many different options for timber species, truss styles, and embellishments to the frame. A timber home can be styled in any manner from rustic to contemporary to classic New England traditional - or anything else a designer can envision.
Timber Frame Glossary
Here are some (but not all!) of the terms often used to describe parts of a timber frame. Check out Timber Frame Glossary for more terms.
- Beam - A horizontal timber used in the structure’s framework. They are supported at the ends and can be either load-bearing, supporting joists, or non-load bearing.
- Girt - A key horizontal timber or beam used to connect posts or sills. A girt running in the wall direction is called a wall girt and a girt running in the bent direction is called a bent girt.
- Hybrid - A type of building that combines the methods of timber framing and conventional stick-frame building or log construction.
- Joints - when two timbers or frame pieces come together. Joints can be simple or decorative and include mortise and tenon, lap joint dovetail, tying joint, and scarf joint, among others.
- Mortise and Tenon - A fastening method for two pieces of wood. One piece of wood has a slot, while the other component has a projecting member that fits into the slot.
- Posts - The main vertical timbers that support the frame.
- SIPs - (structural insulated panels) cover the timber-frame. They are composed of two layers of wood filled with a highly dense insulating foam.
- Timbers - The wooden posts and beams that make up the structural frame.
- Truss - A rigid triangular composition of timbers with stiffening struts. There are several different styles of trusses Trusses that support the roof of the structure.
What are the Different Types of Timber Frame Trusses?
The type of support your frame needs, and your personal preference, will determine which type of timber frame truss you choose to use. The simplest form of a truss is a triangle, but most designs require further stiffening members within the truss.
A basic triangle joined at the apexes. It forms a simple triangle and is often used as a secondary load-bearing component to some of the more aesthetically appealing truss designs.
King Post with Struts
A King Post Truss is a cost-effective design and is particularly attractive when modified with curved braces and webs. It has a central post and usually additional struts
This truss incorporates two vertical posts spaced apart in the triangle. It is a good truss to use if a window is to be placed centrally under the peak of the truss.
A timber frame scissor truss has diagonal chords that support the rafters and ties the members into place.
Throughout history, many cathedrals were designed as a Hammer Beam Truss. This design has a central arch and is more complex in nature than most other truss types. The style has a heavier, more massive feel than other truss designs.
What is a Timber Frame Raising?
When cutting a timber frame, all of the structural timbers for a building are prepared ahead of time in the shop. The timbers are sized, planed, and joinery cut, and then test-fit before transport to the building site. Then onsite the bents are reassembled on-site. Once assembled they are raised from horizontal to vertical one at a time. As each bent is raised, it is connected to the bents already in place with horizontal beams. Then when all of the bents are in place the roof rafters and/or purlins are added.
A timber frame raising can take place by hand for smaller frames, through the use of gin poles, ropes, and lots of muscle. For larger frames, cranes are often utilized to lift bents and timbers into place.
Once the frame is raised most timber framers carry on the topping out tradition of nailing an evergreen bough to the highest point of the frame. This symbolic act marks the completion of the raising.
Check out some of the recent timber frame raisings reported to TFHQ - HERE
What are SIPs and Why Are the Beneficial in Timber Frame Construction?
SIPs (structural insulated panels) are the most common way to enclose a timber home. A SIP is composed of an insulating foam core (usually expanded or extruded polystyrene) sandwiched between two structural facings, often oriented strand board or plywood. SIPs can enclose an entire frame, leaving all the beautiful timber visible on the inside and forming an airtight barrier against the elements. The result is a building system that is strong, energy-efficient, and cost-effective.
SIPs are available in a variety of thicknesses and sizes, ranging from 2 to 12 inches thick and in sizes from the standard 4-by-8 to 8-by-24 feet. SIPs cut heating and cooling costs by as much as 60 percent over other types of house cladding. SIPs can outperform stick framing on energy efficiency by 40 to 60 percent.
SIPs can be cut at the job site to fit the home’s specific floor plan and window and door locations. Or the panels can be cut at the factory by the manufacturer exactly to the home’s design and then numbered for easy installation, which results in savings in materials and resources.