How Much Does a Concrete Slab Cost? (2023)

By Amanda Lutz

Aug 18, 2023
Mixer track pouring wet cement to form a building foundation. Construction workers in the process of forming a concrete slab at the construction site.

Affiliate Disclaimer: All products and services featured are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

The average cost of concrete slab installation is around $5,400. Most concrete slab projects cost between $3,600 and $7,200. Residential concrete slabs are useful for supporting the weight of cars, sheds, patios, and even houses. The first step of adding a new feature, from building an addition to finishing a basement, is often pouring a concrete slab. We’ll show you what determines this pricing and break down your choices when it comes to pouring concrete.*

*Article cost data via Angi and Home Advisor.

Compare Quotes from Foundation Specialists
Just answer a few questions, and we’ll take care of the rest!

 


 

Concrete Slab Major Cost Factors

The most relevant factors to price are the slab’s size, thickness, and means of reinforcement.

Slab Size

The larger the slab, the more concrete it requires and the longer it takes to pour, increasing the price. Thus, concrete slab installation is priced by the surface area’s square footage.

Cost by Size

At an average price range of $4 to $8 per square foot, here’s how cost varies by slab size.

Slab DimensionsSize in Square FeetCost Range

10’x10′

100

$400–$800

12’x12′

144

$576–$1,152

10’x20′

200

$800–$1,600

20’x20′

400

$1,600–$3,200

20’x30′

600

$2,400–$4,800

30’x30′

900

$3,600–$7,200

40’x40′

1,600

$6,400–$12,800

Slab Thickness

In addition to surface area, the slab’s thickness will determine the volume of concrete needed. Concrete is often sold by the cubic foot or cubic yard. For reference, one cubic yard of concrete will cover an area of 81 square feet to a depth of four inches.

Cost by Thickness

Most concrete slabs are between 4 and 6 inches thick, but heavier applications capable of withstanding more weight may require up to 8 inches. You can also request a slab with thicker edges which will add about $1 to $2 per square foot to the following prices.

Slab Thickness (in Inches)Cost per Square Foot

2″

$4.55

4″

$5.35

5″

$5.80

6″

$6.20

8″

$7.00

Reinforcement of the Slab

Most large or thick concrete slabs require internal reinforcement. For residential applications, wire mesh is often sufficient, but heavy-duty reinforced concrete slabs may require iron rebar. Slabs may also need insulation backing and waterproofing.

Cost by Reinforcement

Here’s how much these reinforcements will add to the cost of a concrete slab.

ReinforcementCost per Square Foot

Wire mesh

$0.35

Styrofoam underslab

$0.50

Vapor barrier

$0.50

Rebar

$1.60

Compare Quotes from Foundation Specialists
Just answer a few questions, and we’ll take care of the rest!

 


 

Additional Factors Affecting Concrete Slab Cost

Depending on your concrete project’s specifics, you may also encounter the following additional costs.

Concrete Grade

Though some people use “cement” and “concrete” interchangeably, cement is actually an ingredient in concrete. Concrete mix also contains sand and aggregates that make it stronger. Thus, a pure cement slab is weaker and used less often than concrete.

Concrete mixtures are graded with the letter M followed by a number—the higher the number, the more aggregate in the mixture, and the more heavy-duty use it can endure. Most residential projects require M15, M20, or M25 concrete. High-strength concrete mixtures, which go all the way up to M70, are typically used for commercial purposes. Generally, the higher the grade, the more it will cost.

Finishing Materials

If your project is serving as a hidden foundation for another home feature, basic concrete may be sufficient. However, if the concrete will be visible as a concrete floor or patio base, you may want a decorative finish. You can stain or dye the concrete for an additional $6 per square foot on average. The concrete can also be stenciled, textured, or stamped to imitate the look of other materials such as tile, marble, or slate for about $10 per square foot. For around $15 per square foot, you can request multiple colors, patterns, or embossing. On the high end, specialized techniques such as hand-sawing and engraving cost $18 per square foot or more.

Permits

Not all concrete slab installation requires a permit to meet building codes. For example, a simple concrete foundation to support a small shed or outbuilding doesn’t usually call for a permit, but a concrete patio above a certain grade or a concrete driveway above a basement structure usually does. Check with your local building permit office or consult with concrete contractors to determine what you need.

Removing Old Concrete

If you’re replacing a concrete slab, you’ll need to have the old slab demolished and removed. This usually costs between $2 and $6 per square foot, depending on the slab’s thickness.

Repairs

Concrete slabs are highly durable, but they will develop cracks over time. Depending on the old slab’s condition, you may be able to repair it instead of replacing it. Sealing minor cracks with epoxy costs around $0.20 per linear foot. Resurfacing the slab tends to cost between $3 and $5 per square foot.

Subbase Preparation

To improve drainage around a concrete slab and keep it from shifting as it settles, the slab is often installed atop a layer of gravel, sand, or crushed stone that serves as a sub-base. This layer must be compacted and leveled before the concrete can be poured. Depending on what you’re using the slab for, you may want a layer of styrofoam to act as an insulator or a vapor barrier for extra waterproofing. Site preparation costs for a slab will depend on the sub-base material and local labor costs.

Type of Project

Common construction projects often require predictable sizes of concrete slab. Here are some common projects and their average prices.

ProjectAverage Cost

Shed base

$480

Fire pit

$700

Parking pad

$1,200

Driveway

$3,000

Patio slab

$3,100

Garage floor

$3,460

RV pad

$3,840

Mobile home base

$9,720

Monolithic slab foundation

$12,300

 


 

How to Choose the Right Type of Concrete for Your Slab

Concrete types are based on the ratio of ingredients and any additives. Here are the most commonly used in residential slab construction.

All-Purpose Concrete

All-purpose concrete is widely used in the country because it represents a good balance of strength, durability, price, and weight. It’s a uniform mixture of 10% cement, 20% water, 30% sand, and 40% gravel. For DIY jobs, you can purchase bags of dry materials and add your own water, or you can rent a cement mixer. Because this type of concrete is standardized and premixed, it’s the easiest to use.

However, all-purpose concrete is not the best at withstanding pressure or wear and tear and can get slippery. It’s also porous and may stain and erode if not sealed. All-purpose concrete costs about $120 to $170 per cubic yard. It’s most useful for concrete slabs for sheds or patios that bear a moderate amount of weight.

High-Strength Concrete

The amount of pressure that a material can withstand is measured in pounds per square inch (PSI). All-purpose concrete can withstand about 2,500 to 4,500 PSI, but concrete mixtures that withstand 6,000 PSI or more are labeled as high-strength concrete. Because this concrete is stronger, you can use less of it for the same purpose, and it’s better suited to bear the weight of vehicles and large buildings. It’s also less porous and thus less susceptible to chemical and oil spills.

This added durability comes at a higher price, roughly twice the cost of all-purpose concrete. Because it requires skilled installation and a special curing process, it’s not DIY-friendly, so you’ll pay extra in installation costs. It may be necessary for heavy-duty applications such as supporting an outdoor hot tub or forming the foundation for a large home.

Crack-Resistant Concrete

This is essentially all-purpose concrete with additional fibers in the mixture for better binding. It won’t necessarily hold more weight, but it will resist cracking or breaking due to wear and soil shifting. Crack-resistant concrete is a good choice for high-visibility surfaces that don’t need heavy reinforcement but could use some extra durability, including sidewalks, driveways, and patios. It’s a little pricier than all-purpose concrete at about $130 per cubic yard and may require a specialty sealant.

Reinforced Concrete

Here, the distinguishing feature is not the mixture or additives but the mesh or rebar around which the concrete is poured. This gives the slab far more strength so that it’s able to withstand 40,000 to 60,000 PSI. It’s used in building foundations and commercial or infrastructure applications. The trade-off is that it’s heavy and requires maintenance. Foundation repair costs for reinforced concrete are quite high because this type of concrete often requires quick patching.

Precast Concrete

The above types of concrete are all poured on-site, but concrete slabs can also be pre-poured in a factory for greater uniformity. Since precast concrete is cured before it arrives, it makes for quicker construction, and the factory can use various molds and designs to make the slab to your specifications. It must be transported to your location, though, and this will add to the slab’s base cost. Also, the slab is usually transported in multiple parts, which must be installed and joined by professional concrete contractors.

 


 

How to Reduce Concrete Slab Costs

To keep concrete slab and foundation costs as low as possible, follow these tips.

 


 

How to Hire a Professional

Hiring a concrete contractor is similar to hiring most other types of building contractors. Here are some things to keep in mind.

 


 

Our Recommendation

Concrete slabs often serve as the foundations for important home features and even homes themselves. Thus, it’s usually a good idea to have professional contractors pour your slab. However, smaller projects may be within the purview of some handy homeowners. We recommend learning about different types and mixtures of concrete before taking on this home improvement job.

Compare Quotes from Foundation Specialists
Just answer a few questions, and we’ll take care of the rest!

 


 

Concrete Slab Cost FAQ

How long does it take for a concrete slab to cure?

According to the Concrete Network, it takes about a month to cure a concrete slab to the point where it can support heavy vehicle traffic. However, it’s safe to walk on after 24 to 48 hours, and you can drive light vehicles on it after about seven days.

How do I maintain and clean my concrete slab?

Clean mold and mildew off the concrete with a weak bleach solution. Baking soda will soak up oil or grease stains. Mop the entire surface with dish soap as a degreaser. Concrete can stand up to a pressure washer for stubborn cleaning jobs. To reduce cleaning needs, seal the concrete with an epoxy sealer, and reapply as needed.

What are the advantages and disadvantages of a concrete slab?

Here are the benefits and drawbacks of using concrete as a foundation.Benefits:Slab-on-grade foundations are often the most cost-effective choice.A slab requires less maintenance, as it’s less prone to water damage and pest infestation.Drawbacks:Plumbing and gas lines must be sealed into the concrete, making them difficult to access for repairs.Slab foundations are a poor choice in cold climates where they’re likely to crack as the ground freezes and thaws.

How do I prevent cracks and damage to my concrete slab?

The first step to preventing cracks is ensuring the concrete is mixed properly and contains enough water. The sub-base for the slab must also be carefully prepared so the slab will remain level and well-supported. Including wire or fiber mesh in the mixture and cutting joints into the concrete to redirect cracks will also help.

What are the environmental impacts of a concrete slab?

The production of concrete emits a substantial amount of CO2 into the atmosphere, and porous concrete also absorbs a great deal of water. Mining and pouring concrete both destroy natural environments. That said, the individual impact of pouring a small concrete slab is minimal, and you can reduce this even further by using recycled concrete and ensuring your lawn irrigation system is directed away from concrete slabs.