Most barndominiums are built with sturdy metal frames anchored to concrete slabs. If you want a 16×20 barndominium, you may build a 16×20 slab. So, how much does a 16×20 concrete slab cost?
The national average price of a concrete slab is $4 to $8 per square foot with a median price of $6. At 320 square feet, a 16×20 concrete slab may cost $1,280 to $2,560. Using the median price of $6, a 16×20 concrete slab may cost about $1,920.
The cost of a concrete slab depends on several factors, including its thickness and the use of additional materials or techniques.
Standard Features for a 16×20 Concrete Slab
You can choose from a variety of options when pouring a concrete slab. However, the average cost of a concrete slab is based on a slab with specific features. Here is what you typically get when choosing a standard concrete slab:
- 3,000 PSI concrete poured to a thickness of six inches
- 2×6-inch lumber boards for creating a wood form
- Rebar for supporting the perimeter of the concrete slab
- Fiber mesh reinforcement inside the concrete slab
- A contractor and laborers
Completing it yourself or choosing other features may result in a different price compared to the estimate of $1,920. Here are some of the details used to determine the cost of a concrete slab:
- The thickness of the slab
- The features you choose
- The region where you live
Some regions cost more compared to others. For example, if you build in Washington or California, you may pay more compared to someone in the south or the Midwest.
Some plots of land also cost more to build on. If your site includes a lot of trees and shrubs, you may spend more to prepare the site.
Cost of Materials for a 16×20 Concrete Slab Based on Thickness
The thickness of the slab determines how much concrete and other materials you require. A thinner slab costs less, as you need less material. Here are the price estimates for the material needed for different thicknesses of concrete slabs:
- Four-inch slab – $2.83 per square foot
- Five-inch slab – $3.20
- Six-inch slab – $3.57
A four-inch slab reduces the cost of pouring a concrete foundation by about $0.74 per square foot. If you plan on pouring a 16×20-foot concrete slab, you may spend $236.80 less.
Features That Increase the 16×20 Concrete Slab Cost
Six inches is the standard thickness for a concrete foundation. A thinner foundation may require additional support from one of the following options:
- Thickened edges – $1 per square foot
- Vapor barrier – $0.50 per square foot
- Wire mesh reinforcement – $0.40 per square foot
These features help strengthen the foundation but also increase the cost of materials by about $1.90 per square foot. A 16×20-foot concrete slab covers 320 square feet. With all three of the features listed above, you may spend an extra $608.
Can You Save Money with a DIY 16×20 Concrete Slab?
Another major consideration is whether you should hire a contractor or pour the concrete slab yourself. The average price of $6 per square foot includes about $2.40 for labor. A DIY concrete slab may cost closer to $3.60 per square foot.
Based on these estimates, the cost of materials for a 320-square-foot concrete slab is about $1,152. Hiring a contractor for the same project may cost about $1,920, depending on the features that you choose.
Working with a contractor may cost close to $800 more compared to paying for the materials and pouring the foundation on your own. However, the extra money saves you from the hard work involved in preparing and finishing a concrete slab. In the end, hiring a professional is often worth the extra cost.