Preparing the foundation is one of the first steps in building a barndominium. If you are planning an 80×100 barndominium, you are likely planning an 80×100 concrete slab.
So, how much does an 80×100 concrete slab cost?
An 80×100 concrete slab covers 8,000 square feet. For $6 per square foot, an 80×100 slab may cost $48,000. However, the national average cost of a concrete slab varies from $4 to $8 per square foot, resulting in a price range of $32,000 to $64,000.
Not all slabs include the same features, which means that your project may cost closer to the upper or lower end of the price estimates.
What Are the Features of the Average 80×100 Concrete Slab?
Using the average price of a concrete slab assumes that your slab will include the same features. Here is what is included when you choose a slab with standard features:
- 3,000 PSI concrete measuring six inches thick
- 2×6-inch wood forms around the perimeter of the slab
- Fiber mesh reinforcement inside the concrete
- Rebar around the inner perimeter for reinforcement
- A contractor and laborers to pour and finish the concrete slab
Depending on where you live, you may want to choose other options for your concrete slab, such as extra reinforcement or a thinner layer of concrete. These details impact the price:
- The thickness of the concrete slab
- Using extra materials for reinforcement
- The costs of materials and labor in your region
The region you choose for your barndominium has a large impact on the cost of the slab. Additional preparation work for removing trees and shrubs adds to your cost.
Materials and labor may also cost more in certain regions. For example, prices are often higher on the west coast and in the northeastern states compared to the south and the Midwest.
How Much Does Thickness Impact the Cost of an 80×100 Concrete Slab?
The high-end estimates for pouring a concrete slab are based on the prices for a six-inch slab. Here is a comparison of the price per square foot for materials for concrete slabs of different thicknesses:
- $2.83 per square foot for a four-inch slab
- $3.20 per square foot for a five-inch slab
- $3.57 per square foot for a six-inch slab
A four-inch concrete slab costs about $0.74 less per square foot. An 80×100-foot concrete slab covers 8,000 square feet. Choosing a thickness of four inches may reduce the cost of materials by about $5,920.
What Factors Increase the 80×100 Concrete Slab Cost?
Choosing a four-inch concrete slab reduces the initial cost of materials. However, you may also need to reinforce the thinner foundation with one or more of the following:
- Thicker edges cost an extra $1 per square foot ($8,000)
- Adding a vapor barrier adds $0.50 per square foot ($4,000)
- Using wire mesh instead of fiber mesh adds $0.40 per square foot ($3,200)
The combination of all three features may add $15,200 to your total. Choosing a thicker slab may keep you from needing these extras.
Does Pouring the Concrete Yourself Save Money?
The median price of $6 per square foot for a concrete slab includes the cost of hiring a contractor and paying for labor. Hiring a contractor and paying for labor accounts for about $2.40 of the $6 per square foot estimate.
At a price of $3.60 per square foot, an 8,000-square-foot slab may cost $28,800 instead of $48,000. You may save about $9,200, but completing the project yourself increases the risk of mistakes. If you want to ensure that your barndominium is erected on a sturdy base, hiring a contractor is worth the extra costs.