Timber framing 101: modern design meets traditional craftsmanship in today’s timber frames.
A timber home is a kind of house that uses a frame structure of large posts and beams that are joined with pegs or by other types of decorative joinery. Almost always, the walls of the structure are positioned on the outside of the timber frame, leaving the timbers exposed for visual effect.
Timber framing is strong, old and so well-established that they used to just call it building. It forms the basis of a building that will last for hundreds of years. One of the big advantages of timber-frame construction is that it is so strong it doesn’t need load-bearing walls cutting through the middle of the house, so you can design the layout in any configuration you want, including a totally open great room/dining room/kitchen/entry. On the other hand, in open designs, the frame connects the volumes and brings them down to a more human scale due to the warmth of the wood and the joinery.
The skeleton of timbers also can be covered any way you want, so your timber home can look like any other style of house and can fit in anywhere.
How are Log & Timber Homes Different
Timber frames are often confused with, but are quite different from log homes. The main distinction between log homes and timber homes is how they use the wood. As a result, they achieve sharply different looks. And because timber homes can use a variety of exterior materials having nothing to do with the inside, they may not be recognizable as timber frame homes, whereas log homes are always identified as such.
In general, log homes have a horizontal profile and timber homes are vertical. These tendencies result from the way to logs are laid and the frame is raised. See more about how timber-frame homes are built in the “Build” section, beginning on page 36.
Benefits of Timber Framing
Beyond the aesthetics of exposed timber and open floor plans, timber structures enjoy a durability unmatched by conventionally-built homes. They also provide more structural integrity in the unfortunate event of fire damage, as the large timber supports are more resistant to burning completely through than the thinner cuts of wood that make up conventional building structures.
Finally, a timber home affords the owner opportunity to make a bold design statement, as timbers come in a number of sizes, shapes and colors. A timber home can take on a casual or rustic mountain style, an ornate Victorian style, the more restrained feel of a classic New England home, or any style in between.
Like most specialized art forms, timber framing has a language all its own, with terms for the various tools, materials and construction methods. Below is a brief list of commonly-used timber frame terms to help you better understand the process.
- Timbers are the wooden beams that comprise the home’s structural frame.
- Posts are the main upright timbers that comprise the timber frame.
- Crossbeams connect the post beams, providing stability.
- Joints are where two timbers or frame pieces come together. Joints can range from simple to highly decorative and include lap joints, mortise-and-tenon joints, dovetailed and pegged joints, among many others.
- A truss is a rigid triangle of timbers. Trusses provide column-free floor space and are typically incorporated on the top floor.
- Hybrid is a type of building that combines the methods of timber framing and conventional stud-frame building or, in our industry, log construction. Combining building styles can sometimes save you money and will definitely add visual interest to a home.
- SIPs (structural insulated panels) sheath the timber-frame structure. Made of two layers of durable, flat wood and filled with a highly dense insulating foam in between, SIPs have more or less revolutionized the timber frame building process.
Timber Home Anatomy
Timber homes are complete structures made of vertical posts and horizontal beams to form cross sections called bents. Other members provide support, bracing and structure to the frame. The most common members are shown in the illustration below.
SIPS: What You Need To Know
SIPs (structural insulated panels) are the most popular way to enclose a timber home. Although individual products from manufacturers vary, today’s SIPs all have a solid core of insulation sandwiched between two layers of oriented strand board (OSB).
Other materials used in SIPs include plywood, wafer board, sheet metal and gypsum board. The white core often is polystyrene, extruded polystyrene, Styrofoam or polyurethane — the same durable yet lightweight foams used in bicycle and motorcycle helmets and egg cartons.
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.
Panels generally weigh less than 4 pounds per square foot, making them light enough to install by hand. A crane often is used for larger roof panels or for lifting bundles of panels on the job site and depending on the size of the home, it can be enclosed within days or even hours.
Other benefits include:
- They’re flexible. SIPs can arrive at the home site in bundles of large generic panels that builders cut to fit the home’s specific floor plan. Or panels can be cut exactly to the home’s design at the factory by the manufacturer and then numbered for easy installation, which results in less wasted materials and resources.
- They’re energy efficient. SIPs cut heating and cooling costs by as much as 60 percent over products used for conventional “stick” construction. Even where wall thickness is the same, SIPs outperform stick framing on whole-wall energy performance by 40 to 60 percent.
- They’re soundproof. SIPs block sound like few other materials — a big perk, especially in bedrooms, dens, home offices and media rooms. For more information, visit sips.org.
Let’s Talk Trusses
The kind of structural support your design requires, as well as personal preference, will determine your home’s truss system. A triangle is the simplest form of truss, but its use is limited to small buildings. Adding a king post in the center allows for a wider span. Queen-post trusses, in contrast, look like a rectangle within a triangle. The dramatic hammerbeam truss is used to span large interior spaces and enables ceilings to soar.
- Achieves the cathedral quality
- Creates vaulted spaces
- Can be enhanced with embellishments
King Post with Struts
- The most cost-effective
- Offers a strong, sturdy appearance
- Creates a cozy, intimate feeling
Queen Post (modified)
- Can span distances of 30 feet or more
- Offers an open area in the center of the truss
- Visually lowers the ceiling height for a more intimate feel
- Perfect for those seeking something unique
- Can create a narrow, cottage-like aesthetic
- Ideal for steep roof pitches