Footings Explained by King Piers
King Piers LLC and our team of Foundation Repair Specialists are saving foundations throughout the Midwest. If your basement wall is leaning inward our Methodology is non-intrusive and does not damage the wall as other wall straightening systems often do. The King Piers LLC Team will travel anywhere in the USA to save a sinking home, building, or structure. The King Piers Methodology came about from the 35-plus years of foundation repair making the King Piers System the very best for your home or building. The King Piers Footing Support Pier System is vastly different than that of the Helical type piering systems. The Methodology behind the King Piers Footing Support Pier is that almost all the homes built across the USA are built to the standard minimum, footings included. The King Pier System does not remove or break off sections of the footing where the King Pier is being installed under the footing, as other systems do. We simply hollow out underneath the footing and install our King Pier. The King Pier will have 2 pours of concrete. The 1st pour will be 3ft thick of high-strength concrete reinforced with fiber mesh, and this will be our pushing platform, which will enable our 30-ton hydraulic jacks to lift our King Pier which lifts the footing back to its correct level elevation. After the lift, we will use steel shims to fill the gap from the top of the 1st pour of concrete to the underside foot of the King Pier. Pull the hydraulic Jacks out of the hole then encase the King Pier with our 2nd pour of high-strength concrete, fully encasing the King Pier and Footing. The King Piers System is nothing more than simple physics used at its best.
Virtually daily, I see work from other foundation repair companies that basically sold the customers on a bill of goods that ends up not good. King Piers LLC prides itself on being the absolute best at straightening a wall that’s leaning inward or outward, lifting a footing that has sunk due to drought, time, or due to substandard compactable soil. Time-tested and proven the King Piers Methodology is far above the rest. The King Piers Team will travel anywhere in the USA to save a sinking Building, Home, or Structure! King Piers LLC is the ONLY Footing Support Pier in the industry. No other system GUARANTEES to raise a sinking footing back to level, no matter how many inches the footing has sunk. If you desire 5-Star Foundation Repair on your home or building King Piers LLC is the right choice! Call today for a Free No Obligation Estimate on proper foundation repair.
If you are interested in a DIY system, King Piers now offers our entire kit available to you DIY’ers!
Note: When your footings sink, the foundation walls will follow. King Piers LLC is the only Pier installer in the USA that GUARANTEES to lift your sunken footing back to level, PERMANENTLY! IS your foundation #kingpierstrong?
The footing is the thing upon which the home rests. Where the home meets the soil. The first member of the load-bearing structural systems of the home.
The footing is also an integral part of the foundation of the structure. . . that upon which the first floor is built.
For the purposed of discussion, we talk about the footing and the foundation separately.
Review
The structural elements of the home are those which carry the weight or load of the home to the earth on which it rests. Hence, they are often referred to as load-bearing elements or load-bearing systems.
They include the Footings, Foundation Walls, Floor, Walls, Ceiling, and Roof. These elements must be properly designed and constructed. For they must not only support their own weight, but a portion of that from above. For example, the walls must be strong enough to support the weight of the ceiling and the roof.
The Footing
The footings are placed under all load-bearing parts of the foundation, i.e. piers, columns, foundation walls, etc.
Concrete Footings
Footings are almost always concrete. The footing is usually formed by concrete poured into a trench and constrained by some kind of forms.
Most homes are constructed on 2500 psi (pounds per square inch of compressive strength when fully cured at 28 days) concrete footings. In some areas, steel reinforcing rods, also called re-bars, are required in the footings. This makes the concrete much tougher and less likely to fail.
Steel reinforcing rods are required in the footings in areas where the existing soil does not present a good bearing capacity, such as sand. When soils move around more drastic solutions are requires. See “Active Soils” below.
Dimensions
The dimensions of the footings will vary from place to place, again depending on the bearing capacity of the soils present.
The concrete footing details for your home may need to be designed by an engineer – depending on the type of soil on your lot.
Your building department and your footing/foundation subcontractor will be able to advise you on this.
In many areas a footing that is 8″ deep and 16″ wide is used. When the width is increased, the code requires an increased thickness.
You can imagine that if it is too wide and not deep enough, the weight of the house bearing down on it could snap it in half like a saltine cracker. The projection of the footing on either side of the wall is supposed to be no greater than the depth of the footing.
The bottom of the footing should be at least 12″ below the finished grade line (surface of the ground). It may need to be deeper. It must be below the frost line. Water expands when it freezes.
If the bottom of the footing is not below the frost line, it may be exposed to the upward pressure of the freezing ground water, which may cause structural damage to the home.
Reinforcing the footing with steel rebars is helpful in strengthening the footing. Your subcontractor will (or should) know what will be required on your lot. Talk with him about the design of footings. Also talk with your building official about this and about the design of the foundation walls.
Minimum Width of Concrete or | ||||||
Load-Bearing Value of Soil (psf) | ||||||
1,500 | 2,000 | 2,500 | 3,000 | 3,500 | 4,000 | |
| 1-Story | 16 | 12 | 10 | 8 | 7 | 6 |
| 2-Story | 19 | 15 | 12 | 10 | 8 | 7 |
| 3-Story | 22 | 17 | 14 | 11 | 10 | 9 |
4-Inch Brick Veneer Over Wood Frame or 8-Inch Hollow Concrete Masonry | ||||||
| 1-Story | 19 | 15 | 12 | 10 | 8 | 7 |
| 2-Story | 25 | 19 | 15 | 13 | 11 | 10 |
| 3-Story | 31 | 23 | 19 | 16 | 13 | 12 |
8-Inch Solid or Fully Grouted Masonry | ||||||
| 1-Story | 22 | 17 | 13 | 11 | 10 | 9 |
| 2-Story | 31 | 23 | 19 | 16 | 13 | 12 |
| 3-Story | 40 | 30 | 24 | 20 | 17 | 15 |
Load Bearing Capacity
So how do you know what the load-bearing capacity of your soil is? You could have a soils engineer take a sample and test it.
That probably won’t be necessary, unless the building official requires it. In all likelihood, your subcontractor and/or the building official will know what kinds of soils are typical in your area and what kinds of footings and foundations will be acceptable.
Active Soils
Active soils are very fine particle clay soils, e.g. Bentonite, that expand when they absorb moisture. If active soils are present in your area, your footing and foundation system must be designed by a structural engineer who is familiar and experienced with these conditions. These footing/foundation systems are complex.
The engineer may require the home to rest on concrete piers, called caissons, dug down to bedrock, and the use of special “void materials” to keep the expansive soils from causing the foundation to move.
Do not try to design this system yourself. It requires special knowledge and testing of the soils present on your lot.
Draining
Footings should be well-drained to prevent the damage that water pressure and freezing water can cause. This is accomplished with sand, gravel, and drain pipes.
Keys
A footing key is a groove of some king formed on the top of the footing, down the center lengthwise.
It’s purpose is to keep a concrete foundation wall poured on top of the footing from shifting from side to side.
Rebar sticking up out of the footing is also a good solution. Note that chances of such movement are pretty remote unless you are in an earthquake or active soil area, in which case you will be taking other, more extreme measures to keep your home from falling!
Stepping
When installing trenched, flat, formed, and poured in place footings on a sloped lot, it is usually helpful to “step” the footings down the hill.
Gravel Footings
Considering a wood foundation for your new home? Homes with wood foundations are often built on crushed stone or gravel foundations.
Slab homes can have a traditional footing and foundation wall. Or they can have a “turned down” area at the perimeter which becomes the footing for the home. The latter is commonly used in warmer climates where the frost line is not a concern. In other words, you don’t have to worry about freezing ground water causing your house to heave upward.
For more Footing explanation – visit our post Footings 101.
For a Free No Obligation Estimate on your home’s foundation contact us today!
Follow us on YOuTube!