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Supports carry load from the structure above into the ground below. This short article covers why they matter in residential work, how they are sized and placed, and which materials are commonly used.

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Why supports matter

Supports give the structure strength and stability. That matters most in places carrying significant loads, and in places where the layout calls for more support than the surrounding structure provides. Openings, long spans, and points where several members meet are the usual candidates. Without adequate support at those points, load has nowhere efficient to go.

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Sizing and placement

The load capacity and stresses that the structure would be subjected to are normally calculated by a structural engineer or architect while designing supports. The required size and placement of the supports follows in part from those calculations. In practice that means:
  • establish the loads reaching each support point
  • confirm the capacity required at each one
  • set size and position so the load path is continuous down to the foundation
Placement is rarely a free choice. Architectural layout, foundation positions, and buildability all constrain it, so sizing and placement are usually settled together.

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Common materials

Concrete, steel, and wood are frequently used as supports in residential construction. The material selection is determined by:
  • the building’s design
  • the required load capacity
  • additional factors such as price and availability
No one material is correct by default. A steel post may suit a heavily loaded opening where a timber post would be oversized. Timber may suit repeated light-duty locations where it matches the surrounding framing.

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Where Calcs.com fits

Calcs.com includes calculators for steel, timber, and concrete member design to standards including AISC, NDS, and ACI 318. Use them to check a support once the loads and the arrangement are established. The calculation supports the decision. Selecting the arrangement, the load path, and the material remains an engineering judgment, and responsibility for the design stays with the engineer.