Week 4

 STRUCTURAL SYSTEMS

GINA CHRISTOPHER 

STRUCTUAL SYSTEMS BASICS 

Interior designers do not deal with structural systems, but it is important to recognize the building's structure and know when an engineer or architect is required on a project. The main purpose of structural systems is to carry the loads of a building and transfer them to the foundation. There are three primary types of structural systems: bearing walls, stud walls and structural frames. These systems are usually composed of wood, steel, and concrete/masonry. Bearing all construction relies on the entire wall to carry all loads to the foundation beneath. The stud all system relies on several small members to carry loads to a horizontal plate that in turn distributes the weight to a sill plate. The structural frame system is composed of columns and beams that transmit loads to the foundation. The four primary characteristics of a structural system are stability, strength/stiffness, economy and aesthetics. There are several types of loads that act upon a building and to which the structural system must respond such as live, dead, uniform, concentrated, static, and dynamic loads. Several forms have been developed to resist loads within a building and to respond to tension, compression and shear forces. These structural forms include cable, post and beam, truss, arch, and shell. 

HISTORIC SYSTEMS VS. SYSTMES WE USE TODAY

Historically, most buildings in the U.S. were constructed of wood. The first from of wood construction was heavy timber frame and then mortise and tenon followed. As mentioned above, today we use systems of wood, steel, and concrete/masonry. 

Heavy Timber Construction

OTHER SYSTEMS

 In addition to traditional structural systems stated above, several new materials have been introduced, and some traditional building materials have been reintroduced. These systems include structural insulted panels, cob construction, straw-bale construction, adobe construction, rammed-earth construction, and other alterative building methods. SIPs are becoming popular because they use 30 percent less wood and is made of rice or wheat straw. Cob construction used earth, straw, water and sand. This material can be formed into a variety of shapes. Blaes of straw is the primary wall component in straw-bale construction. Adobe consists of dirt with added water. Large, load-bearing walls are used in rammed-earth construction. Cord-wood construction used "Cord" wood, or what appears to be firewood held together with concrete. Alternate systems include bamboo construction, earth-sheltered construction, gabion walls, sandbags, structural biocomposite, fiber-reinforce plastics and carbon fiber, and insulted concrete forms. 

Rammed Earth Architecture 

Cob House

Abode Construction

RECYCLED MATERIALS/SUSTAINABILITY

Reclaimed lumber, or lumber from old barns and other buildings, has become a recycled new building material for flooring and other applications. A key determining factor in deciding on a structural system to meet sustainability goals relies on the embodied energy of the chosen system. Fun fact, my parents went to a recycled lumber place and had a step stool and counter made for their bedroom!

ICF (ALTERNATE BUILDING SYSTEM RESEARCH)

Insulted concrete forms (ICF) consist of rigid insulation (molded expanded polystyrene) forms held together with either plastic or metal. These are used as formwork for a poured concrete wall. These are often used for foundations but can also be used more extensively. ICFs provide high insulation and are naturally pest resistant. Blue Maxx. Eco-Block, Rastra Block, and Tech Block are some manufactures that provide ICFs.