Many buildings constructed in the nineteenth century and earlier are timber-frame structures. Builders used plentiful old-growth timber and adapted European construction methods to the new world. While the behavior of timber braced frames are fairly complex, these buildings were built without the aid of structural engineering calculations and design standards. To ensure that the building was safe and useable, the builders could not deviate too far from their prior experience. As a result, historical timber-frame buildings follow common forms and floor plans. Even as light wood-frame construction began to replace timber framing in the late nineteenth and early twentieth centuries, vestiges of timber framing practice persisted.
While traditional timber frame structures and later light-frame wood structures have outward similarities, their structural behavior differs significantly, resulting in light-framed structures being more easily modified. What would be straightforward renovations in conventional light-frame wood construction may introduce complications requiring the involvement of a structural engineer in a timber frame structure.
Homeowners and even some residential contractors can be surprised by the cost of engineering services. Most residential projects do not require engineering, Homeowners are seldom in the position to retain an engineer. In addition, engineering fees can be confusing to the uninitiated and are especially counter-intuitive when it comes to residential projects. This unfamiliarity can lead to unrealistic expectations.
One of the ways that the residential codes are more permissive than general building codes is their treatment of geotechnical investigations. Conventional residential construction is lightweight and the prescriptive foundation design provisions in the code are very conservative, yet typically cost-effective. There are circumstances, however, when performing a geotechnical investigation is beneficial or necessary for a residential project. Therefore, the decision as to whether to perform a geotechnical investigation warrants more attention then it usually receives.
Most people understand that earthquakes can produce catastrophic damage to the built environment. However, given that large earthquakes are relatively rare, and that the television news cameras typically move on a few days after any disaster, a lot of people’s understanding of the effects of earthquakes may be shaped more by bad disaster movies than reality. Continue reading “What Everyone Should Know About Earthquakes and Structures”