Terminology

• Spread (isolated) footing: square or rectangular pad under a column
• Continuous (strip) footing: footing running under a wall
• Combined footing: one footing carrying two or more columns
• Mat foundation: one large slab carrying the whole building
• Allowable bearing pressure: soil capacity in psf from the geotechnical report or presumptive values
• Frost depth: depth below which soil does not freeze; footings bear below it or are frost-protected
• Frost-protected shallow foundation: insulated shallow footing for heated buildings
• Stepped footing: footing that steps down with grade
• Pier / pedestal: short column from footing up to grade
• Grade beam: reinforced beam spanning between footings or piles
• Over-excavation: removal of poor soil replaced with engineered fill

Standards

Ratings

• Footing size set by load divided by allowable bearing pressure; thickness and reinforcing by shear and bending
• Settlement limits from the geotechnical engineer
• Concrete strength by seismic design category and exposure

Test standards

• ACI 318: footing design
• ACI 301: concrete specification
• ASTM D1557 / D698: soil compaction tests
• ASCE 32: frost-protected shallow foundations

Materials

• Concrete: normal-weight; minimum strength set by the code and seismic design category
• Reinforcing: bottom mats in spread footings; longitudinal bars in strips
• Anchor rods and dowels: connections to columns and walls
• Insulation: for frost-protected shallow foundations

Detailing

• Base footing design on the geotechnical report, not presumptive values, for anything beyond small buildings
• Keep footings below frost depth; step footings with grade
• Coordinate footing elevations with utilities, elevator pits, and adjacent foundations
• Provide dowels and anchor rods located to the column grid
• Inspect bearing soil before placing concrete

Uses

Specific uses

• Low- and mid-rise buildings on competent soils
• Column footings for steel, concrete, and timber frames
• Wall footings for masonry and concrete walls
• Retaining wall footings
• Equipment pads and site structures

Pros and cons

Pros

• Lowest-cost foundation where soils allow
• Simple to build with common trades
• Easy to inspect before placement
• Fast schedule

Cons

• Not suitable for weak, expansive, or deep soft soils
• Large footings conflict with utilities and property lines
• Differential settlement risk without good soils data
• Excavation in groundwater requires dewatering

Manufacturing and cost

Construction

• Excavate to bearing; inspect subgrade; form or trench-pour
• Place reinforcing and embeds; pour; cure; backfill

Main manufacturers and suppliers

• Simpson Strong-Tie (anchors and hold-downs)
• Dayton Superior
• PERI USA

Trade associations: American Concrete Institute and National Ready Mixed Concrete Association.

Typical costs

• Concrete footings, installed: about $300 to $700 per cubic yard, averaging about $450 on accessible sites
• Continuous footing material, small sections: about $5 per linear foot (12 in. by 6 in.) to $19 per linear foot (24 in. by 12 in.)

Sources

• UpCodes: 2024 IBC Chapter 18 soils and foundations, https://up.codes/viewer/department-of-defense/ibc-2024/chapter/18/soils-and-foundations
• Latest Cost: concrete footing cost per cubic yard, 2026, https://latestcost.com/concrete-footing-cost-per-cubic-yard/
• Inch Calculator: concrete footings cost, 2026, https://www.inchcalculator.com/how-much-do-concrete-footings-cost/
• ACI: concrete standards, https://www.concrete.org/
• Wikimedia Commons: Foundations-types diagram.svg, by Bartek444 (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:Foundations-types_diagram.svg