How Much Does Poured Concrete Foundation Cost?

Average Cost 0f a Concrete Foundation

The cost of a poured concrete foundation with minimum wall height of 8 feet ranges from $18,500 to $34,000 for sizes from 800 to 1,600 square feet. The minimum cost is higher than our starting Cost of a Block Foundation because that range includes block crawlspaces with a height of less than 4 feet.

Walls of a poured concrete foundation are usually 8 feet high, though some homeowners prefer a height of 9 or 10 feet to provide more room for overhead plumbing, wiring and a drop ceiling. Most poured foundation walls are 8 inches thick, but thicker walls might be used when surrounding soils are clay and therefore very heavy when retaining water.

The cost of a poured foundation includes professional work from start to finish – excavating the foundation, pouring footings, setting the forms and installing rebar, and of course the concrete walls. Installation also includes adding stable base materials like pea stone for the slab, pouring and finishing the slab and may include the installation of a drain tile or a French drain around the foundation.

Waterproofing the exterior of the basement is usually an extra expense but might be included in the poured foundation cost estimate. The same is true for the installation of a sump pump and crock or basin to house it.

Average Cost Ranges

Overview of Full Basement Foundations

Poured foundations are a popular choice for full basements including those partially or completely below grade and for walkout/daylight basements. Wall forms can be used to create the footprint you want, and the work goes more quickly than when a cinder block foundation is installed.

While poured concrete is used in crawlspace construction too, this page of Costimates is about full foundations, aka full basements.

The advantages of poured vs block foundations include quicker installation, less potential for leaks, easy and effective waterproofing and versatility of design.

The disadvantages are a higher cost for materials and less potential savings by doing it yourself.

Is your property suitable for a full foundation? In many building projects where no municipal sewer is available, a perc test is done to determine which type of septic system can be used. The test results might also indicate whether the soils and the seasonal water table allow for a full basement.

And where will you build? A formal property survey might show where local authorities have identified suitable building sites.

Poured Concrete Full Foundation Cost Factors

How much is a poured foundation? Your price will fall between or $14.50 – $26.00 based on these factors.

Note: The square footage is priced based on the foundation’s footprint, not on the square feet of wall space.

• Foundation Height – Standard height is 8 feet, but if you want more room above, consider a 9-foot or 10-foot foundation.
• Wall Thickness – 8 inches is standard, but walls up to 12 inches thick are used when the soil on the property is clay. Clay holds water and becomes very heavy, swelling and pressing in from the sides even when sand or similar stable materials are used for backfilling the foundation.
• Foundation Complexity – More than 4 corners, windows or door openings on a walkout side and other features like the installation of a basement hatchway, that cause more work will raise cost.
• Site Conditions – Digging in rocky soil, working around trees or wet conditions making access difficult can increase cost.
• Excavation Depth and Infill Materials – Foundations need to set on stable soils like sand, gravel or pea stone. The local soils determine how deep below the foundation depth the excavation should go and therefore how much material should be trucked in and spread.
• Permit Cost – You’ll need a permit for the foundation. The price range is given below.
• Professional Fees – If you are required to hire an engineer or architect for foundation design, extra fees could run into the thousands of dollars.
• Sump Pump Installation – Most basement foundations include a sump crock and pump plus drain tile from the crock to the outside of the house. This should be considered an extra expense.
• Insulation – This is another separate cost to consider. Insulation can make the same warmer and less humid, which is especially useful if you plan to finish the basement for living space.
• Interior Basement Sealing – This is often done where moisture is a significant problem. Interior basement sealing should be complete before the interior is finished, of course.

Poured Foundation Services and Costs

As noted in our Slab Foundation Costimate, material costs, not including labor costs, are:

• $35 – $55 per Cubic Yard | Pea Stone or Gravel for beneath the slab and around the perimeter of the foundation
• $110 – $160 per Cubic Yard Delivered| Mixed Concrete Delivered for Footings and the Core
• $0.12 – $0.20 per Square Foot | Vapor Barrier for beneath the slab
• $1.50 – $4.00 per Square Foot | Professional Exterior Waterproofing
• $50/Gallon or $200/5-gallon | DIY Foundation Waterproofing with each gallon covering approximately 175 square feet (applied with a roller)
• $0.55 – $0.70 per Square Foot | Steel Rebar or Mesh Reinforcement

Estimating tip: One cubic yard of material covers 108 square feet to a depth of 2”, 81 square feet to a depth of 4” and 54 square feet to a depth of 6”. Slabs are typically 4” thick. Walls are 8” to 12” thick.

Concrete Foundation Form Rental

Did you know that you can rent the forms and connectors needed to form your own foundation walls. This might be of interest to you if you plan to do it yourself.

$1.25 – $1.80 per Square Foot + Delivery and Pickup | Form Rental – cost is for square footage of the forms. For example, if you plan a 32’x40’ foundation that is 8’ tall, you’ll need 144 linear feet (32+32+40+40) of forms times 8 for height, or 1,152 square feet of forms for a cost of $1,440 to $2,100 plus delivery and pickup charges which are determined by distance from the rental yard to your job site. Though the forms needed are measured in singular terms (1,152 sq ft of forms) you’ll actually receive twice that amount, since you need a form on each side of the foundation wall.

Foundation Size and Cost

Here are sample job costs for common foundation sizes. They are broken into three tiers – Easy, Average and Difficult.

• Easy: $14.50 – $22.00 per square foot
  8-foot walls. Good access and site conditions near the road; 4-6 corners. Example: A flat or nearly flat city or suburban lot with dry conditions and soils that are easy to work with.
• Average: $16.00 – $24.00 per square foot
  8 or 9 foot walls. 6-8 corners. Some excavating challenges such as rocky soil or trees making access difficult. Example: Large suburban lot or a rural property with the building site well off the road. Damp conditions and/or possible freezing temperatures.
• Difficult: $17.50 – $26.00 per square foot
  8-10 feet walls. 8 or more corners. Poor site conditions. Difficult access and concrete pump required. Example: A sloped lot possibly treed or with wet soils preventing easy access.
  

Let’s apply these general guidelines to poured concrete  foundation prices.

800 Square Feet – $16.50 – $26.00/square foot

• Easy: $13,200 – $16,000
• Average: $15,500 – $18,750
• Difficult: $17,000 – $20,800

1,200 Square Feet Foundation – $16.00 – $24.50/square foot

• Easy: $19,200 – $24,500
• Average: $24,000 – $27,750
• Difficult: $23,250 – $29,400

1,600 Square Feet Foundation – $15.00 – $23.75/square foot

• Easy: $24,000 – $28,500
• Average: $27,800 – $34,500
• Difficult: $33,700 – $38,000

2,200 Square Feet Foundation – $14.50 – $22.00/square foot

• Easy: $31,900 – $40,750
• Average: $38,800 – $45,650
• Difficult: $42,750 – $48,400

Permits, Inspection, and Labor Costs

Permits and Inspection

• $200 – $1,000 or more | Every foundation job requires a permit that includes inspection of the footings and at least one additional inspection. Cost of the permit is determined by the size of the foundation.

Labor Cost

Our estimate on the average cost of labor is 44% of the total foundation cost. HomeAdvisor gives a total labor cost range of 40% to 60%, which can be accurate depending on site factors and complexity of the work.

Here are some of the labor costs and related charges for construction of a foundation.

• Wages | $20 – $45 or more per hour. High wages in the construction industry mean that foundation cost is rising. Laborers start at about $20, while concrete finishers, forepersons and other skilled tradespeople are paid $45/hour or more. In total, an average poured foundation requires 100-200 hours of labor at a cost of $5,500 to $9,000 total.
• Excavation | $100 – $200 per hour for an excavator and operator. The 8-12 hours needed for transportation, excavating the foundation, loading the equipment, etc. comes at a cost of around $2,000 for most jobs.
• Base Materials with Delivery | $35 – $55 per cubic yard. Stable materials like sand, gravel and pea stone are used beneath the foundation slab floor and around the perimeter to assist with drainage and keep heavy soils from pressing against the walls. A 1,600 square foot foundation needs 30-35 cubic yards of material at a cost of $1,500-$1,800 or more when trucked in from a significant distance.
• Vapor Barrier Installed | $0.25 – $0.50 per square foot. Most foundation installers insist on installing vapor barrier beneath a slab foundation.
• Concrete Delivery | $110 – $160 per cubic yard. A 1,600 square foot concrete floor that is 4” thick requires 20 cubic yards of concrete at a cost of $2,200 to $3,200. Using 8-foot walls that are 8” thick would require another 35 cubic yards of concrete at a cost of $3,850 to $5,600.

Time Required for Poured Foundation Construction

The schedule below can easily be changed by weather, materials or contractor delays.

• Up to 1 Day | Site Excavation
• Half Day | Pouring the Footings plus a few days to allow them to harden and get them inspected
• 1-2 Days | Installing the Wall Forms
• 2-4 Hours | Pouring the Walls plus several days for the concrete to harden before the forms are removed
• Half Day | Spreading Base Materials for the slab
• Up to 1 Day | Pouring and Finishing a concrete slab

Related Projects

Having your home’s poured concrete foundation installed is the first step in a wide range of home construction, maintenance and property development projects you might want to add to the list.

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DIY or Hire a Pro

You’ll have a big job on your hands if you DIY a poured foundation for a full basement. While it might be easier than laying a block foundation, there are still plenty of steps and room for error. Skills will include running an excavator, digging and pouring footings that must be absolutely level, putting together the wall frames (a multi-person job) and leveling/finishing a concrete slab. Additionally, you’ll have to schedule the various stages in order to keep the work flowing or face potential lengthy delays.

Keep in mind that you’ll also have rental expenses. And you might pay more for concrete, pea stone and other materials than a foundation contractor would who gets them at wholesale prices.

If you’re still considering it, here is a basic list of steps:

• Get your permit and, if necessary, hire an engineer or architect to design the foundation.
• Order your rented equipment such as wall forms and an excavator to determine when they will be available, and you can get started.
• Determine a workflow schedule, and get subcontractors lined up if you plan to use any.
• Schedule the concrete delivery for a day or two after you believe you’ll have the walls formed – and be sure you know how many cubic yards of material you’ll need.
• Before the excavator is set to be delivered, mark the foundation footprint.
• Use the excavator to dig the foundation and dig 4’ beyond the footprint on all sides. For example, the hole for a 32’x48’ foundation should be 40’x56’.
• Dig the footing trenches, level them, add forms and pour/finish the footings (which can be done with delivered mixed concrete or by using bags and a portable mixer onsite). Give the footings several days to harden.
• Form the walls on top of the footings.
• Have the concrete delivered and pour the walls. Remove the forms after several days.
• Add pea stone or gravel as a base for the slab.
• Complete the slab floor by having concrete delivered and DIY or hire a pro finisher to get a pro-quality finish. Tip: In some projects, you might be able to wait until you’re ready to pour a concrete driveway to pour the basement slab. This might reduce delivery costs.
• Add drainage around the footings/perimeter
• Backfill the foundation