Timber roof truss bridges space above rooms and supports roofs. Trusses occur at regular intervals with purlins connecting them. Space between trusses is called bay. Rafters flatten under gravity, causing wall topple in larger spans
Rafters are structural members extending from ridge to wall plate supporting roof components. Pair of rafters is called a couple. Modern buildings prefer trussed rafters for cost and ease of construction
Spandrel is a triangular space between arch tops and rectangular frames. Term has four to five accepted meanings in architectural history. Includes spaces between curved figures and rectangular boundaries
Steel connections join two or more members together in structures. They can be used with steel and other materials like bricks. Connection strength depends on joint type and proper installation
Most earthquake deaths occur in 2-8 story buildings and offices. Past 40 years' seismic code revisions failed to reduce deaths. Main causes of damage are architectural configuration, inadequate detailing, and construction inspection
Load-bearing walls support themselves and upper elements, transferring weight to foundation. Non-load-bearing walls support only themselves and lightweight items. Removing load-bearing walls can cause serious structural damage