Barndominiums are sturdy structures with frames that are typically anchored to a slab foundation. If you plan on pouring a 12×20-foot concrete slab for a barndominium, you first need to determine the 12×20 concrete slab cost.
A 12×20 concrete slab has a surface area of 240 square feet. The national average cost of a concrete slab is $4 to $8 per square foot. Based on the average prices, a 12×20 concrete slab may cost between $960 and $1,920.
Keep in mind that not all concrete slabs include the same features. Depending on the options you select, the cost of your slab may vary compared to the national average.
What Do You Get with a Standard 12×20 Concrete Slab?
Using the average price of a concrete slab to estimate your costs is helpful if you choose a slab with standard features. Here is what a concrete slab typically includes when spending the national average of $6 per square foot:
- 3,000 PSI concrete with a total depth of six inches
- Fiber mesh material for reinforcing the slab
- Rebar lining the perimeter of the slab
- 2×6-inch lumber for the wood form that surrounds the slab
- A contractor and laborers for pouring and finishing the slab
Not all concrete slabs are six inches thick or use fiber mesh reinforcement. Choosing other options will change the price. Some of the details to consider include:
- The thickness of the slab
- The features and materials used
- The cost of materials and labor in your area
The cost of materials and labor varies across the country. Prices are often less expensive in the Midwest and the south compared to the west and northeast.
Some areas also require more work to create a level surface for the foundation. You may need to pay for tree removal and other site preparation work.
What Is the Average 12×20 Concrete Slab Costs of Different Thicknesses?
The thickness of the slab is one of the main details that determine the total cost of pouring the foundation. If you choose a thinner slab, the foundation costs less but may require extra material for reinforcement. Here are the average prices for material for concrete slabs of different thicknesses:
- $2.83 per square foot – four-inch slab
- $3.20 – five-inch slab
- $3.57 – six-inch slab
The difference in cost between a four-inch slab and a standard six-inch slab is $0.74 per square foot. With a 12×20-foot concrete slab, a four-inch slab may cost about $177.60 less.
What Extra Features Increase the Cost of Preparing a 12×20 Concrete Slab?
The cost of materials for a four-inch slab is lower compared to a six-inch slab, but you may need to reinforce the thinner slab with one or more additional materials. The following materials can increase the cost of construction:
- Thickened edges add $1 per square foot
- Vapor barriers add $0.50 per square foot
- Wire mesh reinforcement adds $0.40 per square foot
If you need all three features, you may add $1.90 per square foot to the cost of the concrete slab. With a 12×20 concrete slab, these features may increase your total by about $456.
Should You Pour It Yourself or Hire a Contractor for a 12×20 Slab?
Deciding whether to hire a contractor is another major consideration. The price estimates include the cost of hiring a contractor. Choosing to complete the foundation yourself reduces the base price from $6 per square foot to $3.60 per square foot.
At $3.60 per square foot, a DIY 12×20 concrete slab costs about $864. A 12×20-foot concrete slab is a relatively small size. Yet, pouring 240 square feet of concrete is still a major project. Hiring a contractor can give you peace of mind in knowing that the job is done right.