If you’re putting up a shed, garage, workshop, or storage area, a 24×24 metal building is a great way to go.
In fact, you can often fit the building for somewhere between $7,000 and $10,000. However, you’ll also need a base for that building and a standard slab-on-grade concrete foundation is the cheapest and most efficient way to go.
That 24×24 concrete slab will cost you between $5 and $9 per square foot for a 4” thick foundation. Because the building is relatively small, you shouldn’t need much in the way of extra supports or rafting unless the soil is bad.
This means that you can expect the average cost of a 24×24 concrete slab to be $2,880-$5,184. However, costs can go as high as $8,064, depending on if you need rafting, live in a union area, or require significant excavation to grade the foundation.
Therefore, actual costs will always depend on your location and specific site factors.
What Are 24×24 Concrete Slabs Used For?
A 24×24 concrete slab is 576 square feet of space, making it ideal for a large number of applications. For example:
- Metal gazebos and wind shelters
- Sheds
- Garages
- Small storage areas
- Workshops
- Small offices
- Small stables
- Farm sheds
- Extra commercial space for retail, manufacturing, or office
You also don’t necessarily have to build on a 24×24 slab to make use of it. For example, a simple covered slab is a great place to store supplies. It’s also ideal for mechanics who want an outdoor area to work on cars without the expense of building a full extra garage.
However, in most cases, a 24×24 or 24’2” x 24’2” concrete slab is meant to house a building of the same size. That typically means grading the soil the slab is on.
Depending on the weight of the building and what you intend to store in it, you might also need a sub-base to your foundation. This reinforces soft and unstable soil so that your foundation is solid. You might also want to integrate drainage.
24×24 Concrete Slab Costs
The cost of your 24×24 concrete foundation will heavily depend on your location.
For example, the local cost of labor can range from as low as about $11 per hour to as high as $104. In addition, concrete costs can range from about $104 to over $160 depending on time of year and location.
Therefore, you’ll need actual local quotes to price a concrete slab. On the other hand the following chart details average costs and cost factors in installing a concrete slab.
| Costs | Cost per Sq. Ft. | Low | High |
|---|---|---|---|
| Concrete | $1.28-$2.02 | $739 | $1,166 |
| Concrete Truck | NA | $600 | $1,400 |
| Reinforcing Mesh/Rebar | $0.50-$1.20 | $288 | $691 |
| City Permits/Inspections | NA | $100 | $1,300 |
| Forms | $0.20-$0.80 | $115 | $460 |
| Excavation & Sub Base | $0.50-$1.50 | $288 | $864 |
| Labor | $2-$3 | $1,152 | $1,728 |
| Vapor Barrier | $0.05-$0.20 | $30 | $115 |
| Total | $5.75-$11.15 | $3,313 | $6,424 |
*Please note these costs were based on quotes at the time of writing in July 2023 and may be different at the time of reading. Actual costs are subject to location, time of year, and market. Please use these numbers as a basis for your own research. Costs are for a 4” thick concrete foundation.
You’ll also want to check which of these elements you actually need. For example, if you can rent the concrete truck for cheaper, if you’re outside of city limits and don’t need the permits, or if you need less reinforcements, etc.
8 24×24 Concrete Slab Price Factors
The cost of your 24×24 concrete slab will depend on a lot of factors, including location, actual material costs, and what you need for your foundation.
1. Slab Thickness
In most cases, a simple 4” thick slab will be more than enough to support a 24×24 building.
However, if you’re using the slab for residential purposes, installing underfloor heating, or parking heavy machinery on the slab, you might want to upgrade to a 6” thick slab. That will increase the costs of materials.
For example, it increases the volume of concrete needed from 7.11 cubic yards to 10.67 cubic yards, for a materials cost increase of $1,109-$1,707 from $739-$1,166.
Otherwise, costs should be roughly the same, although you may want more rebar for a thicker slab. However, the actual cost of concrete will be the most influential cost in increasing the thickness of your slab.
You’ll also have to consider if you’re adding piles around the supports. These provide more support for your metal building and better anchors for the supports. They may also be necessary in windy areas.
Here, you’ll dig into the ground around the supports and have a concrete pour that is at least a foot thick. That won’t add much to total costs, but it will increase concrete usage and will increase excavation costs.
2. Local Cost of Materials
The local cost of materials can vary quite a bit from location to location. For example, the costs of Portland cement change by as much as 50% from location to location.
You’ll also pay vastly different delivery fees for concrete depending on location.
- The cost of concrete can range from $104-$160 per cubic yard depending on location. For a 24×24 slab, you need 7.11 cubic yards of concrete at 4” thick. At 6” thick, you’ll need 10.67 cubic yards of concrete.
- The cost of rebar can range from about $1.25 to $2.50+ per square foot of coverage.
- Mesh can range from $0.5-$0.20 per square foot depending on where you’re at.
- Sand, graven, and sub-base materials can cost from $2-$5+ depending on the location.
Essentially, you’ll have to get a feel for what materials cost locally. Considering that costs can as much as double depending on where you’re at, it will greatly impact what you pay for the slab.
3. Reinforcement Required
If you’re installing a basic concrete slab for a light-use shed, you can get away with minimal reinforcement. That will typically mean installing framing inside the concrete and using mesh to reduce cracking and shifting.
On the other hand, if you’re putting in a slab to support something heavier, you’ll want to add rebar and potentially trenches under the slab as well.
Here, you can typically talk to your construction crew about the strength required and they can simply calculate out how many pounds of weight per square inch of concrete you need and design a slab accordingly. Therefore, costs will vary.
4. Sub-base
You may not need a sub-base. In fact, you may be able to simply grade the ground you’re pouring on and then pour concrete. However, you may also have to install a subbase, for example, if the soil is very loose or doesn’t drain well.
A sub-base provides drainage, stability, and ensures that your concrete slab is there for the long term. For example, loose sand may blow or wash away, which will result in a cracked foundation.
Soil that doesn’t drain may also result in dirt washing away and the same issue. And, if the ground isn’t stable, you’ll have issues with shifting and concrete cracking.
A sub-base remediates each of these issues by replacing the ground immediately under the slab with a layer that remediates the issue. For example, a layer of gravel for drainage or compact caliche.
5. Grading and Excavation
Best-case scenario, you’ll require a simple leveling of the bed for your concrete and you’ll be good to go.
Worst-case scenario, you might have to excavate a significant amount of dirt to level the bed. For example, if you’re building the slab into a hillside, or if you’re building on a site that has dips and raised areas.
Excavation typically costs from about $5 per square foot. Grading costs as little as about $0.10 per square foot for a larger area, but if you’re doing a small 24×24 area, you’ll usually pay a minimum fee to get the bulldozer there.
This means grading costs will almost never be below $100, although your construction company may just bring the bulldozer out as part of the job – so it could be.
6. Local Labor Costs
The cost of labor can vary significantly from location to location. Here, the largest factor is whether you’re in a big city and whether or not the area is unionized.
Why? The cost of construction labor ranges from $10-$104 across the United States.
- Rural/unskilled labor – $10-$15 per hour
- National averages – $25-$45 per hour
- Union rates – $90+ per hour
That works out to a day rate of about $100-$800 per day, for an average of $300 per day, per person on the job. In most cases, you can pour a 24×24 foundation in a single day, with 3-4 people on the job.
That means you’re looking at about $1,000-$2,000 in labor depending on location. However, those costs can go as low as $800 and as high as $3,500 depending on location.
How do you know how many people you need? In most cases, the more people you have for a concrete pour, the better. A faster pour allows you to send everyone home sooner.
So, if your construction company recommends more people, it’s usually a good idea.
7. City Permits & Inspections
Most areas require you to request building and planning permission before you can pour a concrete slab. However, if you’re outside of city limits and on private property, that shouldn’t be an issue.
If you’re inside of city limits, you’ll want to apply for planning permission 30-90 days before you plan to do the work. That should involve the plans for the slab, the engineering designs for the metal building you’re putting in, and your list of construction companies.
This can cost anywhere from $100 to $1,500 depending on location. If you’re downtown in an urban area, you could pay even more, as rates can go up to $10 per square foot.
However, on average, you’ll pay a few hundred for the planning permission, which will include the full scope of the work so you only have to do it once.
8. Optional Extras
There are a lot of extra costs you could have but that are largely just optional. For example:
- Edges – These are separate structures around the outside of your foundation and typically cost from $5 per linear foot.
- Soil Sampling – Soil sampling and testing may be required for your planning permission. Normally you’ll pay from about $700 but up to $2,500.
- Vapor Barriers – These reduce dampness and moisture coming up through the concrete. You can normally expect them to cost from about 20 cents per square foot.
- Finishing – If you want to sand, add a top layer, or smooth your concrete, it will cost $2-$5 per square foot.
Essentially, there are a lot of extras you can opt for, and they can greatly increase the cost of your concrete slab.
24×24 Concrete Slab Cost Calculations (Examples)
The cost of your 24×24 concrete slab will significantly vary depending on factors like location, cost of materials, etc. The following examples include a few different price quotes for different situations:
- 24x24x4” slab on grade – $3,270
- 24x24x4” slab on grade in the city area – $6,424
- 24x24x6” slab on grade with vapor barrier and trenched base – $4,961
- 24x24x6” slab on gravel bed – $4,797
Of course, each of these examples is just an estimate, and you’ll still need a local quote to calculate your own costs.
Why Work With Rex Metal Buildings?
The team at Rex Metal Buildings is available to help you get in touch with a local construction company, so you can find the best deal on your 24×24 slab.
In addition, with a presence and delivery options in all 50 states, we can help you align your slab construction and metal building delivery, reducing your total costs and concerns for the full project.
Next Steps
Use the form at the top of the page to request a quote for a 24×24 slab in your area.
We’ll review costs, find you the best deal, and get in touch with options for your concrete slab.