Structural Engineering: the Basis for Residential Dwelling Construction

Structural engineering is a complex process that is vital to the construction of any residential dwelling. The knowledge base of the structural engineer aids in the calculation the values and measurements of the construction materials, their placement within the structure, and the types of materials selected for the project.

Calculating Values
Calculating the necessary measurements and properties of construction materials for a residential dwelling is a complex and time-consuming process.

For example, when calculating the necessary size of I beams in residential buildings, you must consider multiple factors:

  • maximum bending moment of the beam
  • maximum deflection of the beam at the center of the span
  • width, length, and depth of the beam
  • moment of inertia
  • constant psi rating for the material the beam is comprised of

You must also consider the exterior dimensions of the home, the span if the beams and floor joists the dead and live loads for the structure, and the design style of the roof. If any interior walls will support the weight of the roof, this will affect the necessary I beam size throughout the residential dwelling.

Required calculations for determining the size of a residential steel beam include the allowable bending stress for structural steel, the moment of inertia, and the section modulus of the required beam.

A structural engineer generally performs these calculations. Certain computer software designed specifically for the calculation of

  • beam design
  • floor beam span
  • rafter design
  • header size and span
  • floor joist load
  • cantilever floor joist load
  • residential I beam spans

are useful for quickly calculating these values.

Determining Building Materials

Steel and solid sawn wood are the traditional construction materials used in creating structures. Modern technology has resulted in the emergence of new composite materials and combinations of natural materials that improve the construction process, cost, weight, strength, and stability of a structure.

Solid sawn wood, structural composites, tube steel, solid steel, glulams (glued- laminated timbers), manufactured beams, and I joists are all used in differing combinations during the construction process.

Since each of these materials behaves differently under the stress of a load, calculating the required measurements and values for construction becomes even more complex. The physics behind the effects of weight, wind, water, temperature, and snow directly affect the construction process.

Residential dwelling construction requires a broad knowledge base, prior construction experience, and an understanding of the physics related to the construction materials and the forces that affect them.

December 12, 2007

Structural Engineering