Quick answer
A foundation footing is the wide base at the bottom of a foundation that spreads the weight of a wall, pier or column over enough soil to carry it. It is usually reinforced concrete, and it is placed below the frost zone where the ground freezes.
The footing is the part that actually touches the soil. Walls, piers and slab edges rise from it.
Quick facts
The key facts about Foundation Footing, with sources:
- Job
- Transmit building loads to the ground 1
- Placement
- Completely below the maximum frost penetration depth 1
- Usually limited by
- The bearing capacity of the soil, for strip footings 1
- Code tables
- IRC R403.1 tables give minimum footing depth and width; crushed-stone tables follow soil load-bearing value 2
- Reinforcement
- Spread footings typically need reinforcing bars near the bottom 1
- Edition note
- Footing rules and tables change between IRC editions 2
Key takeaways
- A footing is the wide base that spreads a wall’s or pier’s load over the soil 1.
- Footings are placed completely below the maximum frost penetration depth 1.
- A footing is only as good as the soil under it. Strip footings are usually limited by soil bearing capacity 1.
- Footings come as continuous strips under walls and as separate pads under piers and columns 4.
- The IRC gives prescriptive footing tables keyed to soil load-bearing value, and each edition updates them 2.
- A footing is not visible after construction. Signs of trouble show up in walls and floors above it.
What a foundation footing is
A footing is the bottom layer of a foundation. It is wider than the wall or pier above it, and it is the piece that bears directly on the soil.
FEMA says footings are designed to transmit building loads to the ground 1. FEMA also notes that the foundation system includes both the footings and the foundation walls above them 1.
People often say “footer” for the same thing. It is a trade word, and both terms are common. Footings are almost always concrete and are usually reinforced with steel.
The footing is the part you will almost never see. After the house is built, soil covers it. Our foundation definition shows where it sits in the overall system, and our stem wall page covers the short wall that often rises from it.
General information, not a diagnosis of your house
General information, not a diagnosis of your house. The size and depth of any footing come from plans, soil and code, and cannot be judged from the surface.
How a footing spreads load
Pressure is weight divided by area. A wall that is eight inches thick would press hard on soil if it sat directly on it. A footing makes the contact area larger, so the same weight becomes a lower pressure.
FEMA explains that the weight of the structure creates a vertical pressure under the footing that the soil must resist, and that soils with lower bearing capacity require proportionally larger foundations 1.
For a long wall, the footing runs the full length as a continuous strip. For a column or pier, the footing is a separate pad.
FEMA notes that the load capacity of residential footings, especially strip footings, is usually limited by the bearing capacity of the soil.
Spread footings, which are isolated pads spread over a larger area, may instead be controlled by the footing’s own structural strength, which is why they typically need reinforcing bars near the bottom 1.
Soil moisture and frost act on the footing too. See soil bearing capacity for how soil strength is described, and frost heave for why footings go below the frost zone.
Cross-section of a footing, stem wall, sill plate and floor framing sitting on soil, with the load from the wall passing down through the footing into the soil.
Illustrative, not to scale, not a design. It shows the load passing from the wall down through a wider footing into the soil.
Types of foundation footings
| Type | Shape and use | Notes |
|---|---|---|
| Continuous (strip) footing | A long, wide strip under a wall 1 | The most common footing under home walls; load capacity usually limited by soil bearing 1 |
| Spread or pad footing | An isolated pad under a pier or column 1 | Often reinforced; may be governed by the footing’s own strength 1 |
| Continuous interior footing | A strip under interior piers | USDA notes this was used to avoid differential settlement of piers in one case study 3 |
| Frost-protected shallow footing | A shallow footing with insulation placed to keep frost away | IRC R403.3 and ASCE 32 cover the method 2 |
| Crushed stone footing | Compacted stone beneath a precast concrete wall | IRC table R403.4 sets minimum depth and width by soil bearing value, with stone compacted in 8-inch lifts 2 |
| Pad footing with grade beam | Pads with a beam spanning between them | Colorado names this for moderately to lowly swelling soils 4 |
Cross-section of a footing, stem wall, sill plate and floor framing sitting on soil, with the load from the wall passing down through the footing into the soil.
Illustrative, not to scale, not a design. Labels show the footing, a short stem wall above it, the sill and the floor framing.
Example: how a prescriptive footing table is organized
The IRC includes tables that give minimum footing sizes. ICC’s 2018 summary shows how the crushed stone table is built. This example describes its structure without reproducing numbers, because the real values depend on the code edition and local adoption.
| Step | What you look up | What it tells you |
|---|---|---|
| 1 | Number of stories and wall type | The load per foot of wall: light-frame, brick veneer or masonry wall 2 |
| 2 | Soil load-bearing value column | Lower values call for deeper and wider footings 2 |
| 3 | Wall width | Narrower walls need a wider spread at the same load 2 |
| 4 | Footnotes | Stone consolidated in 8-inch lifts; soil classes follow the Unified Soil Classification System 2 |
A table like this is a starting point. A designer must still confirm the soil value for the site. FEMA says allowable bearing capacity should be determined by a soils engineer, and that table values are for preliminary sizing only 1.
Where footings appear in different foundations
Every foundation type has footings. Under a basement or crawl space, a continuous footing runs beneath the walls. Under a pier and beam floor, pads sit below each pier.
Under a slab, the footing is either a thickened edge poured with the slab or a separate footing and short wall.
Penn State describes a T-shaped slab as three pours, footing then wall then slab, and notes that such designs rely on footer depth to mitigate frost heave 6.
Footings do not have to look the same all around one house. Site slope, soil and load can all change a footing’s depth or width from one place to another. Your plans show what was designed.
Source: [1]
Why a good footing matters
What a sound footing does
What it cannot do
- Cannot fix weak or moving soil on its own; the soil still has to carry the load 1.
- Cannot stop moisture from entering the wall without drainage and dampproofing.
- Cannot be inspected after it is covered. Mistakes are hard to see.
- Sized for a particular load. Adding load later can overstress it, which is why FEMA says to check existing footings before changes 1.
What a footing cannot do
A footing spreads load, but it cannot change the soil. If soil swells, shrinks, consolidates or freezes, the footing moves with it. The Texas bulletin on expansive soils says that shrink-swell soils are a very common cause of foundation problems 5. A shallow footing is exposed to that movement.
It also cannot fix itself. If a footing was undersized, placed on organic soil, or poured on soft fill, it may settle unevenly.
USDA’s study notes that removing all organic matter from the footing hole and sizing the footing for the load help avoid differential settlement of piers 3. Our differential settlement page explains what uneven movement means.
And footing size is not a score. A bigger footing is not always better; the size has to match the load and the soil.
Footing vs. foundation wall
The footing is the wide base. The wall, pier or slab edge above it is a separate part. People call both “the foundation,” but problems and fixes for each are different.
What drives footing cost
We do not print prices. For new footings the drivers are footing length and width, depth, excavation, reinforcement, concrete volume, soil conditions, site access and local labor. USDA’s case study shows the choice between continuous and spot footings can change the concrete needed by a wide margin 3.
For repair, the drivers are the cause, the number of footing locations, access, soil and engineering. Footing repair is not a common homeowner job. Read our cost guide to see how quotes are built and use the pier count estimator for scope questions.
How footings are built and checked
A general outline, not a build guide.
- Learn the soil: A soil survey or test shows whether soil is expansive, compressible or shifting 5.
- Set depth and size: The designer uses code tables or engineering and the soil value for the site 21.
- Excavate: The trench or hole reaches the planned depth and firm soil. Organic material is removed 3.
- Place reinforcement and formwork: Steel bars sit in the trench where the plans call for them.
- Pour concrete: The footing is placed and left to cure before the wall goes up.
- Inspect before cover: A building inspector looks at the trench or footing before it is buried.
Protecting a footing you cannot see
You cannot reach a footing, but you can control what reaches it.
- Keep gutters and downspouts working and discharging away from the wall. Colorado guidance asks that roof runoff be carried well away from the building 4.
- Keep soil sloping away from the house so water does not collect at the base.
- Keep trees and thirsty plants well back; Colorado’s guide advises planting trees well back from the building on swelling soils 4.
- Do not dig beside a foundation for any reason. Exposing a footing can change its support.
- Photograph and date new cracks in walls or floors, and note whether they change.
Risks and when to call a structural engineer
Footings are exposed to frost, soil swell and shrink, weak or fill soil, water at the base and added loads. FEMA says frost-susceptible soils with moisture and freezing temperatures can undergo very large expansions with enough force to move and crack footings, and that thawing can trap water and weaken the soil 1.
You cannot see a footing problem directly. You see its effects: cracks in walls, floors that slope, gaps at corners and doors that stick. These are clues, not a diagnosis. Movement history, displacement, water, construction details and soil change what they mean.
Call a licensed structural engineer if movement is significant, widening or changing; if walls bow or are displaced; if doors and windows stick along with new cracks; if corners separate; or if you doubt safety. Our engineer guide explains who to call.
Never dig under or beside a footing
Digging next to a foundation can undermine a footing and let a wall move. Exposing or undercutting a footing is a job for an engineer-designed process with shoring, not for a homeowner.
Code rules that govern footings
In states that adopt the IRC, footings are covered by section R403.
ICC’s summary of the 2018 edition notes that cast-in-place concrete footing tables R403.1(1) through (3) require both a minimum depth and a minimum width, that Table R403.4 sets depth and width for crushed stone footings under precast walls, and that section R403.3 covers frost-protected shallow foundations drawn from ASCE 32 2.
FEMA says footings should be placed completely below the maximum frost penetration depth, and that local building codes generally specify that depth. Without local guidance, FEMA points to the National Weather Service or the NRCS Soil Survey 1.
Soil rules add to this. Texas’ bulletin says foundations on expansive soils must be designed under IRC R403.1.8, which sends designers to the International Building Code, and soil tests may be needed under R401.4 5. Those numbers are from the 2015 edition. Check which edition and amendments your jurisdiction adopted.
Edition and adoption
Section numbers above come from the 2015 and 2018 IRC as summarized by Texas and ICC. Editions renumber and revise tables. Ask your building department which applies.
Footing compared with nearby terms
| Term | What it is | How it relates to the footing |
|---|---|---|
| Footing | The wide base that bears on soil 1 | This page |
| Stem wall | A short wall rising from the footing to the floor 7 | Sits on the footing; see stem wall foundation |
| Foundation wall | The wall that holds back soil and carries the house 1 | Sits on the footing; often poured concrete or block |
| Slab | A concrete floor poured at ground level 6 | Edge may be a thickened footing; see slab-on-grade foundation |
| Pier | A vertical support that carries a beam 3 | Rests on its own footing; see pier and beam foundation |
Footing myths
- Myth A footing is the same as the foundation.
- Reality The footing is one part. The wall, pier or slab edge above it is another 1.
- Myth Every footing is the same depth.
- Reality Depth depends on frost, soil, load and code. FEMA says local codes generally set the frost depth 1.
- Myth Concrete footings cannot move.
- Reality They rest on soil, and soil can swell, shrink, settle or heave. The footing moves with it.
- Myth A bigger footing always fixes a problem.
- Reality Size must match the load and soil. A footing cannot cure moving or weak soil on its own.
- Myth A crack in a wall tells you the footing has failed.
- Reality A crack is a clue. Movement history, water, construction details and soil all affect what it means.
Regional factors for footings
Frost depth varies by region, and local codes set it. Penn State notes that in cold climates T-shaped slabs rely on footer depth, while frost-protected shallow foundations use insulation and building heat instead 6.
In regions with swelling soils, Colorado’s Geological Survey recommends drilled piers and grade beams in moderately to highly swelling soils and cautions that pad-and-grade-beam designs should not be used in highly swelling soils 4.
Texas ties expansive-soil foundations to the IBC through IRC R403.1.8 5. Ask your building department for your frost depth and any soil rules.
What to do with this
If you are buying or building, ask for the soil report and the footing design on the plans. If you own a house and see movement, record it first. The crack identification tool helps you log what you see, and the elevation log helps show whether floors are changing.
- If Planning a build
- Then Ask for a soil investigation and the footing design before the foundation is poured
- If New cracks or a slight slope, nothing else
- Then Photograph, date and watch for change
- If Sticking doors, new cracks and a sloping floor together
- Then Call a licensed structural engineer
- If A neighbor or contractor suggests digging beside the wall
- Then Do not dig; ask an engineer first
Questions about Foundation Footing
What is a footing on a foundation?
A footing is the wide base at the bottom of a foundation that spreads the load of a wall, pier or column over the soil. FEMA says footings are designed to transmit building loads to the ground 1. It is usually reinforced concrete and sits below the frost zone.
What is the difference between a footing and a foundation?
The foundation is the whole system that carries the house into the ground. The footing is the wide base at the bottom of that system. FEMA treats the foundation system as footings plus foundation walls 1. A wall, pier or slab edge sits on the footing.
How deep should a footing be?
Below the maximum frost penetration depth, as a rule. FEMA says footings should be placed completely below it and that local codes generally specify the depth 1. Soil, loads and foundation type also matter. Ask your building department and check your plans.
Why do footings need to be below the frost line?
Because freezing, moisture and frost-susceptible soil together can lift soil and the footing with it. FEMA says such soils can expand enough to move and crack adjacent structures, and that placing part of the foundation below the zone of maximum frost penetration normally avoids it 1.
How wide does a footing have to be?
It depends on the load and the soil. Weaker soil needs a wider footing, because FEMA says soils with lower bearing capacity require proportionally larger foundations 1. The IRC includes tables that give minimum width and depth by soil load-bearing value 2. Your plans and local code give the figure for your house.
Do footings have steel reinforcement?
Often. FEMA notes spread footings typically need reinforcing bars near the bottom, and says the footing and pier should be reinforced and tied together in pier foundations 1. Whether a given footing is reinforced depends on the design, soil and code, which the plans show.
Can a footing fail?
Yes, if it is undersized, placed on weak or organic soil, undermined by water or digging, or overloaded. A footing problem usually shows up as cracks or slopes in walls and floors above. These are clues, not a diagnosis. A licensed structural engineer should assess movement that is significant or changing.
Can I see my footing?
Usually not. After construction the soil covers it, and in a basement or crawl space the wall hides it. Plans, permits and inspection records tell you what was built. Do not dig beside a foundation to look; that can undermine the footing. Ask an engineer to evaluate if you need confirmation.
What is a frost-protected shallow foundation?
It is a shallow footing that uses insulation, and sometimes heat from the building, to keep frost away instead of going deep. The IRC covers it in section R403.3, drawn partly from ASCE 32 2. Penn State describes it as a single-pour design used in colder climates 6.
Sources
- FEMA P-259, Engineering Principles and Practices for Retrofitting Flood-Prone Residential Structures, 3rd ed. (Jan. 2012), retrieved .
- International Code Council, 2018 IRC Significant Changes (sample: frost-protected shallow foundations and crushed stone footings), retrieved .
- USDA Forest Service, Forest Products Laboratory, Research Paper FPL-RP-664, Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States (Feb. 2012), retrieved .
- Colorado Geological Survey, Special Publication 11, Home Construction on Shrinking and Swelling Soils (Holtz and Hart, 1978), retrieved .
- Texas Department of Licensing and Regulation, IHB Technical Bulletin TB 10-01, Foundations on Expansive Soils – Residential (rev. Oct. 16, 2018), retrieved .
- Penn State Pennsylvania Housing Research Center, Considerations for a Slab-on-Grade Foundation (webinar handout, Feb. 2024), retrieved .
- U.S. DOE Building America (IBACOS), Guide to Closing and Conditioning Ventilated Crawlspaces (Jan. 2013), retrieved .
Expert review
Written by the HyreFoundation Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Facts were checked against the FEMA, USDA, DOE, ICC, state and university documents listed above, retrieved 2026-10-14. Code references are from the 2015 and 2018 IRC as summarized by those sources and may differ by edition. No structural engineer has reviewed this page.
Suggest a correction. We fix errors and say what changed.