On most soils, all footings should be at least 150mm (6") deep, with the bottom 350-400mm (14-16") below ground level. However, thicker and deeper footings should be employed in clay soil. Footing depth depends on several factors such as soil type and load capacity.
The goal is to create an area where nothing can grow through or under it because it's been dug out too far. This stopping place for water is called a "wet well". You need room around the well for drainage pipes, but otherwise you don't want it to be any deeper than necessary. Dampness from water that cannot reach the surface runs down into the ground. The more dampness there is near the surface, the more likely it is that trees will grow in this area rather than elsewhere on the property.
Wet wells come in two varieties: open and closed. An open well is one that has no cover other than earth itself; it allows water to drain away after heavy rains or when the pump is operating. A closed well is one that has some type of cover, such as a cinder block wall or geotextile fabric, over it. The cover provides protection from heat and sunlight and helps retain moisture in the ground surrounding it.
Footings should reach at least 12 inches below previously undisturbed soil. Footings must also be at least 12 inches below the frost line (the depth at which the ground freezes during the winter) or frost-protected. Footings should be a minimum of 12 inches wide. Larger footings are more stable.
Depth and width of footings depend on several factors such as soil type, how much weight you expect to put on the foundation, etc.
The goal is to provide support for an entire building. If you look at a typical house, you'll see that the footing covers the entire area where the floor will be. This is called a full-depth footing. The other common type of footing is called a half-depth footing because it covers half of the area where the floor will be. On houses up to about two stories high, the footing does not have to go all the way down to its full depth. It can stop short if there's room beneath it for plumbing and wiring. For example, if the house has a bathroom on one side only, the footing may stop before reaching the bottom of the wall. There's no need for it to go all the way through to the other side of the wall.
Full-depth footings are most stable but require the deepest excavations and thus the most time and money to complete.
Footings must be built in conformity with the following specifications: 1.4 Soil pressure according to Table R401.2, column K. 2. A concrete footing shall be at least 9 inches wide and 6 inches thick. 3. Wood pilings shall be driven into moist soil and should be capable of withstanding a load equal to 100 percent of the expected maximum winter loading on the house.
The depth of footings depends on several factors such as soil type, amount of moisture present, etc. The required depth is listed in the table below. However, footings do not have to be dug down to this depth; rather, they can be placed in shallow trenches and filled with asphalt or concrete to obtain the required bearing capacity.
Table R401.2 - Required Depth of Footings by Type of Foundation
Soil Type Bearing Capacity (psi) Required Depth (inches) Dry, well-drained soil 10,000 5 Dry, poorly drained soil 7,500 4 Wet soil 6,250 3 Snow and ice 12,000 4 Concrete slab 20,000 5
It is important to specify the exact type of foundation when ordering materials or hiring contractors.
Footings Depth Footings should reach at least 12 inches below previously undisturbed soil. If you are building in an area that is likely to freeze, such as a Wisconsin lake shore, footings should be placed deeper than 12 inches.
The goal is to provide support for your foundation that will keep it from deteriorating due to moisture absorption. The depth of your footing affects how much damage it can cause by absorbing water. If the water is not absorbed by the time you put your house footprint on it, then it's just waste water that needs to be drained away from your house site. However, if the water remains trapped under your home, it can cause structural damage over time.
If you plan to have a pool or other type of water feature in your yard, then you should also install a pool fence to prevent people from coming into contact with the water. This could harm their feet if they climb over the fence and get any wetness on their shoes or boots.
The proper depth of footings depends on many factors such as climate, soil composition, etc. But on average, footings should be at least 12 inches deep. Any deeper and they'll do more help protect your foundation than harm it.
Footings depth of 12 inches Footings should reach at least 12 inches below previously undisturbed soil. If you plan to put water in the footings, the water should not reach more than 2 feet below the lowest point of the footings.
The goal here is to prevent water from flowing into your house through the foundation. This will help prevent flooding and other problems with your home's structure.
You should also try to keep out any vegetation that might work it's way under the footing. This includes plants like ivy that like to grow up buildings. If you cannot see anything growing out from under the footing, then it is safe to assume that nothing will be a problem there.
If you are experiencing any problems with your foundation, such as cracks appearing in walls or floors, these may be signs that it is time for repair. Cracks can appear anywhere along the exterior or interior of your home, so make sure to check all areas when looking for signs of damage.
Crumbling or missing concrete slabs on top of the footings may indicate that there is something wrong with your foundation.
Where freezing temperatures are not a problem, footings can be placed any distance down, so long as they are deep enough to contain water during an average rain event.
The goal is to provide support that will keep your house from being pulled away from its foundation over time due to earth movement or the expansion and contraction of underground fluids. The footing's purpose is to distribute this load evenly across its surface area.
The size of the footing depends on several factors such as the load it will have to carry and the soil it will be placed in. For example, if you were to build a house with 20 percent slope, then the footings would need to be about 40 percent larger than if the house was flat. In addition, if you plan to use concrete for the footings, then the rule of thumb is 2 inches thick for every 100 pounds per square foot of loading.
If you place the footings too close together or leave them exposed, they will cause problems for future construction activities.