How much does a concrete slab cost in Virginia?

There is no set price for a concrete slab in Virginia. Each contractor prices the job from its own costs and the details of your site, so the useful answer is what drives the price and how to get quotes you can compare. Price the same written specification with at least three licensed contractors, and the differences between them start to mean something.

What you are paying for

Volume of concrete. Concrete is sold by volume, in cubic yards, so area and thickness set the biggest single material cost. Quikrete says 4 inches is enough for a driveway that serves only passenger cars, and 5 or 6 inches is recommended where trucks and other heavy vehicles will use it.^[4] Going from 4 to 6 inches adds half again as much concrete. Ask the contractor to order a little over the plan dimensions, since forms and ground are never perfectly true, and to avoid a tiny leftover load.

Truck size and small loads. Ready-mixed concrete arrives in truck mixers that carry several cubic yards. A small patio uses a fraction of a load, so the trip, the crew's time and the setup are spread over very little concrete. That is why a small slab usually costs more per square foot than a large one.

The mix. Outdoor slabs go through freeze and thaw, so ask for the specified strength in psi and whether the concrete is air-entrained, and have both written into the quote. Stronger or faster mixes cost more. Quikrete, for example, rates its high early strength 5000 mix at 5,000 psi after 28 days and says that, because it gains strength quickly, it is ideal for cold weather applications.^[2] Extras such as fibers, integral color and special aggregates add to the price.

Access. A loaded concrete truck is very heavy and may not be able to cross soft ground, loose dirt or residential curbs. A backyard patio behind a fence may need a pump or wheelbarrows, which adds equipment and labour.

Site preparation. The base is labour. Quikrete's instructions start by removing the sod and soil to the desired depth, and for larger jobs or areas of poor drainage dig deeper and add several inches of gravel or crushed stone to the subbase.^[2] VDOT's sidewalk specification has its contractor excavate, shape and compact the earthen foundation to a firm, even surface.^[3] Ask whether the quote includes breaking out and hauling away an old slab, bringing in gravel, or building up a sloping yard, and have each one priced as its own line so you can compare bids.

Reinforcement and joints. Ask what is included and why. Quikrete says it may be desirable to add wire mesh when using its Concrete Mix, and that its Fiber-Reinforced Concrete Mix eliminates the need for wire mesh.^[2] Its instructions also cut 1 inch control joints into the slab every 6 to 8 feet,^[2] and joints do much of the work of controlling cracks; see why new concrete cracks.

Finish. A plain broom finish is the simplest. Stamped, colored or exposed-aggregate surfaces take more time and materials.

Season. In cold weather, a contractor has to protect fresh concrete. VDOT's specification, for example, has its contractor prevent the temperature at the surface of the concrete from falling below 40 degrees F during the first 72 hours immediately following concrete placement.^[3] Blankets, covers and faster-setting mixes show up in a winter quote.

Approvals. Permit rules are set locally, so ask your county or town. Prince William County, for example, lists concrete patio slabs on grade that are not designed to support a future building addition among work that needs no building permit, but notes that zoning or watershed approval will be required.^[9] A new driveway onto a state-maintained road is different: Virginia's access management rules say the property owner shall obtain an entrance permit,^[5] and that grading and installing the driveway from the edge of the pavement to the right-of-way line is the property owner's responsibility.^[5] Virginia 811 says that when you hire someone, your contractor is responsible for contacting Virginia 811.^[10]

Doing it yourself instead

For a small pad or walk, materials are the main cost. An 80 lb bag of Quikrete Concrete Mix yields about 0.60 cubic feet,^[1] so a 10 by 10 foot slab 4 inches thick (about 33 cubic feet) takes about 56 bags, plus lumber for forms, gravel and tool rental. The trade-off is time and the risk of a rushed finish. How to pour a small concrete slab walks through the job.

Getting quotes you can compare

Virginia's Board for Contractors advises getting at least three written bids or estimates using identical plans and specifications, and to beware of any bid substantially lower than the others.^[8] Its rule of thumb for a deposit is an initial deposit of no more than 10% of the total price or $1,000, whichever is less.^[8]

Check the licence class against the price. The Code of Virginia says Class C contractors work on single contracts over $1,000 but less than $30,000, and Class B contractors on contracts of $30,000 or more but less than $150,000.^[6] For residential work, the Board's rules require a written contract that includes a statement of the total cost of the project, the amounts and schedule for progress payments, including the down payment, and a list of the specified materials and work.^[7] The questions worth asking are in what to ask a concrete contractor before hiring them.

Stop and call a pro if

• The slab will hold up a structure, such as a shed, garage or room. That is a foundation: it needs to be designed for the load, and the building office should see it first.
• The driveway meets a state road or a curb. Entrance permits and work in the right-of-way are best handled by a contractor who does them regularly.
• The pour is bigger than you can place and finish before it sets, or a truck cannot reach the site.
• The old slab is sinking or heaving, which points to the base, not the surface.

Getting quotes in Virginia

Loclis lists DPOR-licensed businesses with their licence number and class. Look up concrete contractors in Blacksburg or another town, browse concrete and flatwork, or see all concrete and hardscaping answers. Loclis's own fees are on the pricing page.

Describe the slab once and licensed local concrete businesses quote it.