A concrete slab does not need footings if it’s a patio, driveway or sidewalk slab. However, if the slab is a foundation, it needs a footing. Modern homes require footings under all load bearing walls, columns and support structures to carry the load above. The footings rest directly under the slab along the entire perimeter and beneath all load points. Typically slab foundation footings are at least 3 foot deep or beneath the frost line to prevent heaving caused by the freeze/thaw cycle.
A concrete slab foundation requires footings for the following reasons:
- Help prevent water from seeping beneath the slab.
- Provide support for all load bearing members.
- Help the slab resist cracking and settling.
- Resist heaving and shifting caused by the freeze/thaw cycles.
- Prevent animals from burrowing under the slab.
- Provide a heavy anchor point for structures which helps in high winds and earthquakes.
Modern concrete slab foundations require footings reinforced with rebar. Any structure built on top the slab is then bolted down to the footings with anchor bolts. This helps create a very strong and stable foundation and structure.
Many older homes built on a slab did not have footings. They only have a concrete slab and may or may not have a small trench of concrete beneath along perimeter. This type of construction was common for small ranches and shacks and is no longer legal.
Small structures, like sheds, can typically be built on a concrete slab without footings. The weight of a concrete slab is often enough to support a lightweight structure all by itself.
Types Of Concrete Slabs With Footings
There are types of concrete slab foundation with footings. A typical slab with footings, a floating slab and a monolithic slab.
- Typical Slab With Footings: A typical slab with footings is the most common type used in construction. A footing is a large area of concrete poured below grade that acts as the base of the home’s foundation. The slab is poured directly on top of the footing.
- Floating Slab With Footings: A floating slab is built over footings similar to a typical slab, but the slab floor is poured after the footings and foundation walls are built. This means it “floats” or rests on the footing but doesn’t support as much of the building’s weight.
- Monolithic Slab With Footings: Monolithic slab foundations are the least common type of foundation. We typically only pour monolithic slabs on smaller jobs. With a monolithic slab, the footing and slab are connected and poured at the same time.
Which type of concrete slab with footings is best depends on the structure you’re building, site conditions and local building code requirements. Consider consulting with an engineer, architect or a building official before designing and/or building a slab.
What Are Footings?
Footers, a.k.a. footings, are structural elements of a structure. They’re basically a large portion of concrete reinforced with rebar that’s poured into a form below grade. They’re very heavy and designed to support the structure built atop them. All load bearing walls, columns and beams of a home or building require a footings below.
A footing is a crucial part of a structures foundation. They’re lowest point of a building that comes in contact with the Earth. The entire weight of a structure is carried by the footings which then transfers that weight to the soil.
- Foundation walls, slabs and columns are built directly on top of the footings.
- Footings are typically reinforced with rebar.
- Footings are designed by an architect or structural engineer.
Footings should be designed by an architect or structural engineer based on the structure that’s being built atop it and the soil conditions. There are different types of footings, so it’s important to consider the structure and site conditions before you design the footings.
What’s The Purpose Of Footings?
The purpose of footings is to support the load placed atop them and to anchor the structure to the ground. They are an essential part of a building’s foundation and carry of the load of the entire structure. Footings are essentially just large portions of solid concrete with rebar reinforcement inside. They’re the lowest part of a buildings foundation and sit below grade. Because of how heavy concrete is, footings act as an anchor which holds the structure firmly to the ground.
Every strong and sturdy foundation has footings. They’re required by code for all buildings and residential homes.
Many small size older homes were built on shallow slabs without a proper footing. This is a weak way to build which made them prone to cracking, settling, tilting, heaving and deterioration.
- Footings are an essential part of a strong and durable foundation.
- Building codes require homes, buildings and other heavy structures to have footings.
- They help protect the structure against soil erosion and other environmental factors.
- Some small structure, like sheds, may not require a slab footing.
Footings help distribute the weight of the structure evenly across the concrete foundation. When designed properly, they help prevent the slab from sinking or shifting over time.
Properly designed footings are crucial to the overall success of any building project.
How To Determine If Your Concrete Slab Requires Footings
As a general rule, all large buildings, structures and residential homes require footings. But that doesn’t mean all slabs need them too.If you’re pouring a non structural slab, such as a sidewalk, driveway or patio, you probably don’t need a footing.
- Some garage floors also don’t rest on a footing. Rather, they’re poured on compacted grade and tied into the foundation with rebar. This design allows for some movement of the slab which helps prevent cracking.
- Many small structures, like sheds, do not require a slab footing. The weight and stability of the slab is often enough to support the shed.
- Small slabs like sidewalks and patios usually don’t require a footing.
Before you start a construction project, it’s important to spend time in the planning and design phase. The stability and safety of the structure depends on a solid foundation. Factors such as local building code, the size and weight of the structure, soil composition, and the local climate must all be taken into account when considering your footings.
Consulting with a structural engineer or architect to decide if your slab requires footings. You can also call your local building department for more information regarding small slabs and shed foundations.
Tips On Pouring A Slab Foundation With Footings
Slab foundations with footings can be poured separately or as a single pour. When a slab and footing are poured at the same time, it’s called a monolithic pour. This is a good method for pouring slabs with footings when the job is small. But for large homes required many yards of concrete, it’s better to pour the slab and foundation separately.
The exact requirements for a footing, slab and foundation will differ based on the job requirements, structure and site conditions.
Tips
- Planning: It’s very important to spend time planning your footings, foundation, slab and pour. Determine how much concrete you’ll be pouring and figure out how many workers you’ll need. Also determine how many concrete trucks you’ll need and how they’ll be accessing the site prior to the pour.
- Mark-Out: Accurate marks are crucial when pouring footings. If your marks are incorrect, the structure could be built in the wrong place. Always call for a site mark-out by an engineer so you have accurate marks to measure off of for your footings. to Mark an area 18 inches wide along the perimeter of your foundation.
- Footing Excavation: Dig a trench larger than you need so you have room to work and build forms. Most footings are at least 18-inch wide x 21-inch deep with a bottom at least 36-inch below grade or below the frost line. Dig deep enough to allow for some gravel below the footing.
- Slab Excavation: Dig out enough soil to allow for the concrete and a few inches of compacted gravel below.
- Vapor Barrier: Lay a heavy mil plastic vapor barrier under the slab.
- Gravel: Pour a few inches of gravel under the slab and footing, then compact.
- Reinforcement: Install all your rebar and wire mesh reinforcement. Use chairs to keep them above the ground.
- Pour: Pour, smooth and finish your concrete.
- Curing: Be prepared for various weather conditions to help the concrete cure.
A strong and durable foundation that resists cracking and settling requires properly designed and built footings.
Do All Slab Foundations Have Footings?
Almost all modern slab foundations have footings. However, some older homes built on a slab do not. Many older ranches, cottages and cabins were built on a simple slab without footings. They were then converted to regular residential homes still using the original foundation. These homes are more prone to slab cracks, heaving and lifting because the slabs are weaker and lighter than they should be.
Some slab foundations do not have footings for small structures like sheds. In some cases, a concrete slab is strong and heavy enough to support the weight of the shed.
If you see a modern home built on a slab foundation, it almost always has a footing.
Common Problems With Slab Foundations Without Footings?
Slab foundations without footings tend to suffer from the same problems which includes settling, cracks, heaving, tilting, water erosion and deterioration. The slab will typically crack and heave because it’s not anchors to a footing. This can then cause damage and possible failure of the building on top of the slab. The slab can also tilt, break, shift or allow water to collect underneath it which can destroy a structure.
- Slabs without footings can crack, heave, settle, break or tilt.
- Without footings, water can runoff and collect under the slab which can eventually create a sinkhole.
- It’s easier for animal to burrow beneath the slab without footings to stop them.
- Footings also act as an anchor for a structure which holds it down in high winds.
In addition to providing support for a structure, they also hold the structure down. Footings are an anchor which holds the structure in place during storms with high winds. Without footings, it’s much easier for winds to blow a house over or lift it up.
Concrete slabs without footings are also more prone to animals burrowing underneath them. The footings help prevent animals from getting under the slab because they run deep enough to stop them. This also helps with insects that live underground like ants and termites.
Can You Pour A Concrete Slab Foundation Without A Footing?
Homes, buildings and large structures generally require a footing under the slab. The footing dimensions and depth as well as reinforcement depends on the local building code, type of structure and site conditions.To know for sure, contact your local building department, an architect or engineer and tell them what you want to build.
Some small structures, like sheds, do not require a footing under the slab. The slab itself may be enough to provide adequate support and anchoring for the shed.
Alternatives To Traditional Footings
In some cases, there may be alternatives to pouring traditional footings for your slab. This is something you should discuss with an architect, engineer or your local building department. Whether or not your slab requires footings depends a lot on the structure being built and site conditions.
Frost Protected Shallow Foundation
One alternative solution to traditional footings is a frost-protected shallow foundation. This type of foundation uses insulation to protect your house or structure from frost damage without requiring deep excavation. Instead, a shallow perimeter trench is dug around the perimeter of the structure and filled with insulation. This helps to keep the ground at a consistent temperature, preventing frost from penetrating into the structure’s foundation.
Post-Tension Slabs
Another alternative solution is the use of post-tension slabs. This type of construction involves pre-stressing the concrete to provide greater strength and stability. Post-tensioned slabs use high-strength steel cables that are tightened after the concrete has cured. This creates tension within the concrete, making it stronger and more durable. The reinforcement also minimizes the potential for cracking and other damage over time.
Poured Strip Footings
Poured strip footings are another alternative solution for concrete slab construction. This type of footing involves pouring a strip of concrete along every perimeter foundation wall of the structure to provide a stable base. This differs from traditional footings that require excavation and separate footings to support the foundation. Poured strip footings also require less material and labor, making them a cost-effective option for those looking to save money.
Precast Footings
Precast footings are an option for those who are looking for a faster, economical solution. These footings are precast offsite, then transported to the project location and installed. Precast footings require minimal excavation and can be installed quickly. They are also customizable, allowing for unique floor dimensions and shapes to fit your project’s needs.
Hybrid Foundation Systems
Hybrid foundation systems are becoming more popular in the construction industry. This is a combination of conventional and alternative solutions that provide optimum stability and longevity for your structure. These systems reduce the amount of excavation required while still providing a strong foundation. One example is using steel piles and footings in combination with concrete beams to create a foundation system that is both efficient and durable.
Common Mistakes When Installing Footings For A Concrete Slab
Properly designed and built footings are the foundation of a successful reinforced slab. Making mistakes during installation can lead to costly problems down the road. The most common mistake is not digging deep enough for the footings. While it may seem like extra work, it’s important to follow local building codes and ensure the footings are at the required depth to prevent settling over time and heaving. Make sure your footings are below the frost line so water can’t seep beneath them and freeze. This can lift the footing causing cracks to the footing, foundation and home.
- Another mistake is not properly compacting the soil before pouring the concrete. This can create voids under the slab, leading to cracking or uneven settling.
- It’s also important to make sure the footings are level and square, as even small deviations can cause big problems in the finished product.
- Another common mistake is the mark-out. Always make sure your footings are in the right place before you excavate and pour. If the footings are in the wrong place your structure will be too.
- Using the wrong concrete mix can be a big problem. If you’re footing requires 4000 psi concrete and you use 3000 psi instead, it may not be strong enough to support the structure being built.
- Form blow out is another issue. Concrete is very heavy so make sure to build your forms strong enough to hold the concrete’s weight without a blow out.
There are plenty of things that can go wrong when pouring a footing and slab. Make sure to follow the plans, do your prep work and mark out the footing correctly to avoid mistakes.
Summary: Does A Concrete Slab Need Footings?
A concrete slab does not need a footing if it’s a patio, driveway or sidewalk slab. However, if the slab is a foundation, it needs a footing. Modern homes require footings under all load bearing walls, columns and support structures to carry the load above. The footings rest directly under the slab along the entire perimeter and beneath all load points. Typically slab foundation footings are at least 3 foot deep or beneath the frost line to prevent heaving caused by the freeze/thaw cycle.
A concrete slab foundation requires footings for the following reasons:
- Help prevent water from seeping beneath the slab.
- Provide support for all load bearing members.
- Help the slab resist cracking and settling.
- Resist heaving and shifting caused by the freeze/thaw cycles.
- Prevent animals from burrowing under the slab.
- Provide a heavy anchor point for structures which helps in high winds and earthquakes.
Modern concrete slab foundations require footings reinforced with rebar. Any structure built on top the slab is then bolted down to the footings with anchor bolts. This helps create a very strong and stable foundation and structure.
Many older homes built on a slab did not have footings. They only have a concrete slab and may or may not have a small trench of concrete beneath along perimeter. This type of construction was common for small ranches and shacks and is no longer legal.
Small structures, like sheds, can typically be built on a concrete slab without footings. The weight of a concrete slab is often enough to support a lightweight structure all by itself.
If you have any questions or comments about concrete slab footings, email any time.
FAQs
Does A Concrete Slab Need Footings? ›
A concrete slab does not need footings if it's a patio, driveway or sidewalk slab. However, if the slab is a foundation, it needs a footing. Modern homes require footings under all load bearing walls, columns and support structures to carry the load above.
Are concrete footings necessary? ›Footings in construction are critical, as the footing distributes the weight of the building evenly across the entire structure so that it doesn't sink into the ground. A good footing will also help to prevent water and moisture from seeping into the foundation, which can cause cracks and other damage.
Does a concrete slab have footings? ›A slab-on-grade foundation usually consists of a thin layer of concrete across the entire area of the foundation with thickened footings at the edges or below load bearing walls in the middle of the building.
How deep is a footing for a concrete slab? ›Depth of Footings
Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.
Like all foundations, the slab starts with concrete footing poured 24 inches below projected finish grade. After the footers are poured, a minimum of two layers of concrete block are laid on top of the footers.
What is the minimum for foundation footings? ›| Type of Footing | Minimum Thickness |
|---|---|
| Masonry | 250 mm; twice the maximum projection from the face of the wall |
| Plain concrete | 200 mm, or twice the maximum offset in a stepped footing |
| Reinforced concrete (depth above bottom reinforcement) | 150mm 300mm |
Without a footer under a foundation wall, the wall may actually start to slice into soil much like a knife cuts into a stick of butter. But a footer, because it's wider than the foundation wall, displaces this weight over a much larger area.
What is the purpose of a footing in a slab? ›Footings are an important part of foundation construction. They are typically made of concrete with rebar reinforcement that has been poured into an excavated trench. The purpose of footings is to support the foundation and prevent settling. Footings are especially important in areas with troublesome soils.
Do concrete footers need rebar? ›Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. However, placing reinforcing steel within footings is a relatively easy and inexpensive practice that can provide increased performance.
Do you pour footings and slab at same time? ›Monolithic slabs combine the foundation footings and slab into one piece, allowing them to both be poured at the same time and cut back your time and monetary investment.
Should you put gravel under footing? ›
The top 6 to 12 inches of backfill beneath the slab should be filled with gravel or crushed rock. Portland cement, natural soil, and water are mixed to form a hard, semi-rigid concrete pavement. It is possible to lay a concrete driveway over an existing gravel driveway, but this is not generally recommended.
What thickness of concrete for footings? ›The depth of concrete you need will depend on the use: footings for extensions, for example, will need to be at least 200mm thick, while around 100mm should be deep enough for a shed base.
Why not to buy a slab house? ›One of the most significant potential disadvantages is if the slab cracks. This can substantially compromise the structural integrity of the house and be difficult and expensive to repair. Among the factors that can result in a slab cracking are tree roots, soil displacement, earthquakes, or frozen ground.
What are the disadvantages of a slab house? ›- More Floor Space Required for HVAC Systems. As there is no space under the house to hide water heaters, space heating systems, and air handlers for air conditioning units, these appliances often then find a home on the ground floor of a building with a slab foundation. ...
- Expensive Repairs. ...
- Resale Value.
Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.
What is the difference between a foundation and a footing? ›Foundation is a structure which transfers the loads from the superstructure to the ground, while footing is the foundation which is in contact with the earth. A foundation can be shallow and deep, while a footing is a type of a shallow foundation. so, all footings are foundations but all foundations cannot be footings.
How deep and wide do footings need to be? ›You can look up the recommended footing size, based on the size and type of house and the bearing capacity of the soil (see the table above). As you can see, heavy houses on weak soil need footings 2 feet wide or more. But the lightest buildings on the strongest soil require footings as narrow as 7 or 8 inches.
What size rebar to use in footing? ›There are three different sizes of rebar which are needed for home projects are usually #3, #4, and #5. The rebar size #3 is used for driveways and patios. For walls and columns, #4 rebar size should be used as they require more strength. It is better to use the #5 rebar size for footers and foundations.
Can I pour my own footings? ›We don't suggest pouring your own foundation. It's expensive, time consuming and can be dangerous for DIYers. This is one project that you should hire a professional to do. While it takes a crew of skilled professionals to build a foundation, the process is fascinating.
How is a house attached to a slab foundation? ›Nearly all homes with slab foundations that were originally built to code will have anchor bolts or straps. However, if the house is not bolted to the slab, you have an earthquake weakness. Newer homes generally have anchor bolts or straps. If you have an unfinished garage, you may be able to see the anchor bolts.
Can I pour my own concrete slab foundation? ›
Unless your patio is going to be the size of your driveway, you can pour concrete you mix yourself. Buy your favorite brand and follow the instructions on how to mix. Once you have your concrete mixed, start pouring in the frame over the leveled and flattened ground.
Are footings poured directly on the ground? ›They're generally poured under ground and below the frost line. Footings create a strong and stable base that supports foundations and columns which support buildings and homes. What is this? The main function of a footing is to transfer the vertical load of a structure directly to the soil.
Can you pour concrete against dirt? ›Long story short, yes you can pour concrete over dirt.
What happens if you build without foundation? ›Without it, your house would quickly sink into the ground unevenly, resulting in cracks and damage to your home. A properly built foundation will keep the home even and supported, even during a flood or earthquake. But building a good foundation requires more than just digging into the ground and pouring the concrete.
What are the 3 types of slab foundations? ›- A Typical Slab With Traditional Footings. This is the most common slab foundation type, and is also typical of homes with basements. ...
- A Floating Slab Foundation. ...
- A Monolithic Slab Foundation.
The footing is a type of shallow foundation. Foundation can be shallow and deep. Footing includes slab, rebar which are fabricated of brickwork, masonry or concrete. Foundation types include piles, caissons, footings, piers, the lateral supports, and anchors.
What is the difference between concrete footing and concrete foundation? ›The footing is what's actually in contact with the ground, while the foundation is the structure that transfers the load to the earth. A simple way to visualize the difference when comparing it to the human body would be to view the footing as the actual feet of the legs and the foundation being the legs themselves.
What happens if you don't put gravel under concrete? ›Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.
Does a 10x10 concrete slab need rebar? ›Rebar is not necessary for every concrete project. The general rule of thumb is that if you are pouring concrete that is more than 5 inches in depth, you are probably going to want to add in some rebar to help reinforce the entire structure.
Does a 4 inch slab need rebar? ›So when pouring a simple 4-inch concrete slab do you need rebar? No, you do not need rebar for a 4-inch slab of concrete on grade. A 4-inch-thick slab cast on the ground and in permanent contact with it will float and rebar is not required. Rebar is recommended on concrete measuring 5 – 6 inches thick.
How long to wait after pouring concrete footings? ›
Most concrete achieves its rated strength in 28 days, although in reality the concrete usually achieves its specified strength more quickly than that. In most parts of North America, 3,000 psi is the minimum recommended compressive strength for footings.
How long after pouring footings can you build? ›Curing Times for Concrete
Typical industrial concrete will recognise its full workable strength at the 28 day mark. After 7 days of curing, the concrete will have reached approximately 70% strength. For those who are laying concrete in a domestic area, like the garden, concrete is reasonably set within 24-48 hours.
Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage. Crusher run (a mix of crushed stone and stone dust) and #57 coarse aggregate are two of the best base materials for concrete slabs.
What is the best sub base for a concrete slab? ›The best sub-base for a concrete slab is gravel. The soil has to be prepped first before the gravel can be laid down; pouring concrete directly onto rock is not considered a best practice. You can use different kinds of gravel for the subbase as long as it is clean and uniform in shape and size.
Does a concrete slab need a sub base? ›Subbase for Concrete Slab
The subbase placement is optional and it serves as a work platform for construction of the slab and provide more uniform support for the slab. As the thickness of subbase increases, the ultimate load carrying capacity of slab increases.
GRADE: C25 CONCRETE
C25 is often used as a foundation concrete mix when pouring foundations (footings). It is also the ideal concrete for domestic slab foundations for house and bungalow floors.
Which concrete grade may be used for footings? Footings are typically made of C25, also known as standard mix concrete or ST2 concrete.
How long should concrete cure before putting weight on it? ›Concrete starts hardening as soon as it's poured, but it's far from ready. Give it at least 24 hours of concrete cure time before allowing any light foot traffic and even longer before putting any significant weight on the surface.
What is the problem with concrete slab? ›Cracking - One of the most common problems with concrete slabs is their tendency to crack. Cracking is usually caused by shrinking due to cold, drying, and applied loads (the weight of your infrastructure). The cracks caused by settling over time are what give business owners the most trouble.
How long does a house concrete slab last? ›For large scale projects like buildings, concrete should last up to 100 years if it's properly cared for. Concrete projects that experience more wear-and-tear like sidewalks and driveways have an expected lifespan of about half that—50 years.
What is the life expectancy of a slab foundation? ›
Foundations. Poured concrete block bases and slab foundations will last for a lifetime, 80 to 100 years or more, given they have been constructed with precision.
Do slab homes have moisture problems? ›Excess moisture in the concrete slab can cause serious flooring problems, such as adhesive failure, discolored tile or grout, bubbles in sheet vinyl, and buckling of wood floors. An old slab under existing flooring can easily contain enough moisture to cause these issues for the new flooring.
How do you keep a slab house warm? ›Because concrete floors have a high thermal mass, the best way to warm up concrete floors is by installing an underfloor heating system. Not only does concrete flooring heat up fast, but it also retains heat very well.
Can pipes freeze in a slab foundation? ›If you have a slab on grade foundation, your pipes will be more than six inches below ground. Heat from the ground and from the house will keep the temperature of the soils under the foundation above freezing. You do not need to worry about freezes affecting your underground pipes.
Is gravel needed under concrete? ›Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel is especially important in clay soil because it doesn't drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains.
What is the strongest foundation for a house? ›Poured concrete is the strongest type of foundation for a house. Concrete is incredibly strong and durable, and it can be poured into any shape. This makes it ideal for supporting the weight of a house. Block foundations are also very strong, but they are not as flexible as poured concrete.
How deep should building footings be? ›The depth of concrete you need will depend on the use: footings for extensions, for example, will need to be at least 200mm thick, while around 100mm should be deep enough for a shed base.
What happens if footings aren't deep enough? ›When deck footings aren't poured deep enough, decks can heave. Sandy, well drained soils aren't particular susceptible to frost heave, while soils with higher clay content are prone to frost heave. This is why it's so important for deck footings to extend down below the frost line.
Do concrete footings need gravel base? ›Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.
How thick should concrete footing be? ›For masonry or concrete construction, the minimum foundation wall will be 6 inches. The minimum reinforced concrete footing thickness will be 6 inches or 1-1/2 times the length of the footing projection from the foundation wall, whichever is greater.
How deep should a slab foundation be? ›
A slab foundation is made of concrete that is typically 4" to 6" thick in the center. The concrete slab is often placed on a layer of sand for drainage or to act as a cushion. Houses built on a slab lack crawlspaces, and there is no space under the floor.
How high should footings be above ground? ›A cast or poured concrete pier is often used as upright support to connect the buried footing pad to the structural post above grade. The top of this pier should be at least 4 inches above the soil level under the deck. Your local building department will decide the size, type, and depth of your footings.
What is the most common slab footing? ›Slab-on-ground is the most common type of slab. There are 2 types: conventional slabs with deep excavated beams and waffle pod slabs, which sit near ground level and have a grid of expanded polystyrene foam pods as void formers creating a maze of beams in between.
Can you pour a footing without rebar? ›Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. However, placing reinforcing steel within footings is a relatively easy and inexpensive practice that can provide increased performance.
Can I pour concrete directly on dirt? ›Long story short, yes you can pour concrete over dirt.
What is the best fill under a concrete slab? ›Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage. Crusher run (a mix of crushed stone and stone dust) and #57 coarse aggregate are two of the best base materials for concrete slabs.
Which is better rebar or wire mesh? ›Rebar can be stronger but might be considered overkill for projects While rebar is often stronger than wire mesh, you might find that the level of strength provided by rebar is overkill for most projects. Heavy-duty wire mesh can offer the required level of durability while limiting your costs considerably.