Jackson Hole Timberframe Homes
What is a timberframe?
- A timberframe is a fully braced frame cut from heavy timbers usually joined with traditional mortise and tenon joints and hardwood pegs.
- Timberframe construction has evolved over thousands of years. Almost every culture that has had access to large timber has its own timber framing tradition. Some of the most famous timberframes are European cathedrals and Oriental temples. Prior to the adoption of production stud framing with plywood in the last century, most large structures in Europe and North America were timberframes or heavy timber roof systems above massive masonry walls.
- Timberframes are the Cadillacs of modular construction. By that I mean it’s possible to fabricate a high-quality kit of parts in a controlled shop environment for efficient assembly on site. This is our specialty… www.tetontimberframe.com.
How is timberframe construction different from post and beam?
Timberframes are fully braced structures which resist both gravity loads (snow, floor loads, etc.) and lateral loads (wind and seismic). Post and beam structures also use heavy timbers to support gravity loads, but they rely on shear walls or steel tension bracing to resist lateral loads. A simpler definition might be timberframes stand by themselves while post and beam buildings need shear walls to stiffen them against wind and earthquakes.
How are timberframes assembled and raised?
Timberframes are usually assembled on site in large wall or bent sections that are lifted into place with a crane. The design of the frame and joinery has everything to do with how it is fabricated in the shop and assembled and raised on site. An experienced crew can assemble the wall sections of a large frame in one day and raise it in one or two more.
Frames can also be raised with gin-poles, block-and-tackle rigging and man-power, but you had better have a very good reason to approach the job that way, such as a remote job site with no crane access or re-enacting an old-world raising for publicity. The expense of using a crane is more than offset by the safety and efficiency that it brings to the process versus the risk and logistical challenges of a hand-raising.
How are timberframes enclosed and finished?
There are several excellent, energy efficient enclosure systems for timberframe homes. By far the most common is to wrap the frame with structural insulated panels, or SIPS.
Foam core panels with pre-cut windows applied to a timberframe.
These panels are made with two layers of oriented strand board (OSB) sheathing glued to a core of expanded polystyrene (EPS) or polyurethane foam. The R-value of the panels varies with the thickness and the type of foam used and can be as high as R-49. Perhaps as important as the R-value is the fact that, when properly installed, SIPS create a very tight shell around a frame with little or no air-infiltration or thermal bridging. Much like timberframes, SIPS can be fabricated in a controlled shop environment and delivered to the building site ready to install around the frame. That combination makes it possible to raise and enclose a 3000 SF timberframe home in just a week or so of good weather, any time of year, which translates into big benefits for most projects including reduced schedule, overhead, and exposure to bad weather. Panels are easy to engineer in the sense that they have been thoroughly tested for both gravity and lateral load resistance. Some drawbacks to building with SIPS are they are made from petroleum products which are sure to become more expensive; they are large and costly to ship to remote job sites; and most OSB sheathing contains formaldehyde. For more information on enclosing timberframes with SIPS see Tedd Benson’s excellent book, “The Timberframe House.” Here are some photos of timberframe-panel homes we have built…
- Riley residence from the south
Another option to enclose timberframes is by using straw bales to create an 18” thick wall with an R-value of up to 60. Straw bale construction has only been around as long as baling machines, or just over 100 years, but in that time has been used to create some remarkably beautiful and energy efficient buildings. The benefits of building with bales include the high R-value; the good use of a renewable agricultural waste product; the low cost of material; and the aesthetic appeal of thick, sculptural walls with natural plaster finshes. The primary drawback to building with bales is they are susceptible to mold or fungal growth if they are exposed to water and not thoroughly dried.
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Home Builder Article Author: Adam Riley, has lived worked played in Jackson Hole, Wyoming and Teton Valley Idaho for the past 15 years. He owns and operates Teton Timberframe, LLC and when not raising heavy timber structures, he can be found climbing or skiing in the Tetons.