How to Pour a Concrete Slab Yourself: Equipment, Costs, and Steps

By the team at Beehive Rental & Sales — Serving Southern Utah's contractors and homeowners since 1994.

Pouring a concrete slab is one of the most satisfying and money-saving DIY projects a homeowner can tackle --- if you plan properly and respect the material's unforgiving timeline. Once concrete starts coming off the truck or out of the mixer, you have a limited window to place it, level it, and finish it before it sets. This guide gives you the complete process from excavation to final cure, with the equipment list, cost breakdown, and Southern Utah-specific considerations that make the difference between a slab you are proud of and one you have to demolish.

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Quick Answer: Pouring a concrete slab yourself requires excavating and compacting a sub-base, building forms, placing reinforcement, and finishing the concrete within its working window. Key rental equipment includes a plate compactor for sub-base prep and a power screed or bull float for finishing. DIY slabs cost $3-$5 per square foot versus $8-$15 per square foot for professional installation. BeeHive Rental & Sales in St. George rents all concrete equipment --- call (435) 628-6663 for availability.

Key Takeaways

• •Sub-base preparation is 50% of a good slab --- compacted gravel underneath prevents cracking and settling; never pour concrete directly on uncompacted soil
• •Concrete thickness depends on purpose: 4 inches for patios and sidewalks, 6 inches for vehicle traffic (RV pads, driveways), 8+ inches for heavy equipment or commercial loads
• •In Southern Utah, never pour concrete when temperatures exceed 100 degrees --- rapid moisture loss causes plastic shrinkage cracking and weakened surfaces; schedule pours for early morning (before 8 AM in summer)
• •DIY concrete saves $3-$10 per square foot depending on slab size, making a 20x20 patio a $1,200-$2,000 savings over hiring a contractor
• •Browse concrete and compaction equipment at BeeHive --- compactors, mixers, vibrators, screeds, and finishing tools available for daily rental

Planning Your Concrete Slab

Before you rent equipment or order concrete, answer these questions to properly scope your project.

Purpose Determines Thickness

The intended use of your slab dictates its thickness, reinforcement, and sub-base requirements:

Under-building is the most expensive mistake. A 4-inch patio slab that cracks under the weight of a hot tub costs more to demo and replace than building it 6 inches thick from the start. When in doubt, go thicker.

Calculating Concrete Volume

Concrete is ordered in cubic yards. Here is the formula:

Length (ft) x Width (ft) x Thickness (ft) / 27 = cubic yards

For a 20x20 foot patio at 4 inches thick: 20 x 20 x 0.333 / 27 = approximately 4.9 cubic yards

Always order 10% extra. Subgrade irregularities, form bulging, and minor spillage consume more concrete than you expect. Running short mid-pour is not an option --- you cannot stop and reorder. For the example above, order 5.5 cubic yards.

Ready-Mix vs. Mixing On-Site

Ready-mix delivery (concrete truck) is appropriate for any slab over 1 cubic yard. The concrete arrives mixed, at the correct slump, and can be placed in volume. A standard concrete truck carries 8-10 cubic yards. For residential slabs, you can order partial loads (most plants have a minimum of 1-2 yards plus a short-load fee).

On-site mixing with a concrete mixer is appropriate for very small slabs (under 1 cubic yard) --- shed pads, small stoop replacements, post footings. Mixing on-site is slow and labor-intensive for anything larger.

Permit Considerations

In the St. George area, permits may be required for:

• •Slabs in front yard setback areas
• •Slabs that connect to or modify existing structures
• •Slabs over a certain size (varies by jurisdiction)
• •Any slab that changes drainage patterns affecting neighboring properties

Contact the City of St. George Building Department at (435) 627-4830 before starting. Many simple patio and shed pad slabs do not require permits, but it costs nothing to confirm.

Equipment You'll Need

Plate Compactor (Essential)

The plate compactor prepares your sub-base --- the compacted gravel layer beneath the concrete. Without proper compaction, your sub-base settles unevenly over time, creating voids beneath the slab that lead to cracking and failure. This is the one piece of equipment you absolutely cannot skip.

Use it for: Compacting native soil after excavation, compacting each lift of gravel sub-base, final sub-base compaction before forming.

Concrete Vibrator (Highly Recommended)

A concrete vibrator (also called a pencil vibrator or stinger) consolidates the concrete after it is placed in the forms. It removes air pockets trapped during placement that would otherwise create voids and weak spots in the cured slab. Insert it vertically into the concrete at regular intervals across the slab.

Use it for: Removing air pockets from freshly placed concrete, ensuring concrete fully fills around rebar and mesh reinforcement, improving concrete density and strength.

Bull Float (Essential for Any Slab)

A bull float is a large, flat, smooth tool on a long handle that you push and pull across the concrete surface after screeding. It embeds aggregate, brings cream (the smooth cement paste) to the surface, and removes high and low spots left by the screed. For slabs over 100 square feet, a magnesium bull float with extension handles reaches the center of the slab.

Power Screed (For Larger Slabs)

For slabs wider than 8-10 feet, a power screed (a vibrating straightedge that rides on the forms) levels the concrete surface faster and more evenly than a manual screed board. It is especially valuable for maintaining consistent thickness across large areas.

Use it for: Slabs over 100 square feet, driveways, RV pads, garage floors --- any slab where a manual screed board would be too slow or produce inconsistent results.

Concrete Mixer (For Small Pours Only)

If you are pouring less than 1 cubic yard and do not want to pay the short-load fee for a concrete truck, a rental concrete mixer handles bagged concrete effectively. The Multiquip MC94S holds 9 cubic feet per batch --- suitable for very small pours.

Hand Tools

• •Screed board --- A straight 2x4 or magnesium straightedge for leveling concrete to form height
• •Edger --- Creates a rounded edge along the perimeter that resists chipping
• •Groove cutter (jointer) --- Cuts control joints to control where the slab cracks (it will crack --- you control where)
• •Broom --- A concrete finishing broom creates the textured, slip-resistant surface
• •Hand float and finishing trowel --- For smoothing edges and detail work
• •Knee boards --- Let you kneel on the concrete during finishing without leaving marks

Step-by-Step: Pouring Your Concrete Slab

Step 1: Excavate and Grade

Remove topsoil and organic material to a depth that accommodates your sub-base plus slab thickness. For a 4-inch slab on a 4-inch sub-base, excavate 8 inches below your desired finished slab height.

Grade the excavated surface to be roughly level. It does not need to be perfect --- the gravel sub-base will handle fine leveling. But remove any high spots and fill any low spots greater than 2 inches.

For larger slabs (driveways, RV pads): A skid steer or mini excavator handles excavation dramatically faster than hand digging. BeeHive Rental & Sales rents both, and the time savings usually pays for the rental several times over.

Step 2: Compact the Sub-Base

This step cannot be rushed or skipped.

1. •Compact the native soil first. Run the plate compactor over the excavated surface in overlapping passes.
2. •Add gravel in lifts. Spread 2 inches of 3/4-inch crushed gravel and compact it. Then add another 2 inches and compact again. Building the sub-base in lifts produces dramatically better compaction than dumping 4-6 inches and compacting once.
3. •Verify firmness. Walk across the compacted sub-base. You should not leave visible footprints. If the surface gives under your weight, add more gravel and compact again.

Southern Utah specific: Our dry, sandy soil requires moisture for effective compaction. Water the gravel lightly before each compaction pass --- damp, not muddy. Dry gravel shifts under the compactor without bonding. Wet gravel locks together and stays put.

Step 3: Install Forms

Forms define the shape and thickness of your slab. Use 2x4 lumber for 4-inch slabs or 2x6 for 6-inch slabs.

1. •Set form boards to your desired slab height, accounting for any slope you need (patios should slope 1/4 inch per foot away from structures for surface drainage)
2. •Drive wooden stakes every 3-4 feet on the outside of the forms
3. •Screw the forms to the stakes (screws are easier to remove than nails during form stripping)
4. •Check level across the forms and verify your planned drainage slope
5. •Apply form release oil to the inside faces so the forms strip cleanly

Critical: The tops of your forms are your screed rails --- the concrete surface will match the form height exactly. If your forms are not straight, level, and at the correct height, neither will your slab be.

Step 4: Place Reinforcement

Lay welded wire mesh or rebar grid on top of the sub-base. Reinforcement must be positioned in the lower third of the slab --- not resting on the ground and not at the top surface. Use rebar chairs (wire supports) or small concrete blocks to elevate the reinforcement to the correct height.

For fiber-reinforced concrete: If you ordered concrete with fiber reinforcement mixed in, you can skip separate mesh or rebar for light-duty slabs (patios, walkways). Discuss with your concrete supplier whether fiber reinforcement is sufficient for your slab's intended load.

Step 5: Plan Your Control Joints

Before you pour, know where your control joints will go. Control joints are intentional weak lines that control where the slab cracks as it shrinks during curing (all concrete shrinks and cracks --- the only question is whether you control where).

Control joint spacing rule: Maximum spacing in feet equals 2-3 times the slab thickness in inches. For a 4-inch slab, that means joints every 8-12 feet in both directions. For a 6-inch slab, every 12-18 feet.

Mark your control joint locations on the forms so you know exactly where to cut them during finishing.

Step 6: Pour the Concrete

Timing is everything. Once concrete arrives (via truck or from your mixer), the clock starts. You typically have 60-90 minutes of working time before the concrete sets too hard to finish. In Southern Utah's summer heat, that window can shrink to 30-45 minutes.

1. •Place concrete starting at the far end of the forms and working toward your exit point
2. •Spread concrete roughly to form height using shovels and rakes
3. •Vibrate with the concrete vibrator at regular intervals (every 18-24 inches) to consolidate and remove air
4. •Do not overwork --- excessive vibrating causes segregation where aggregate sinks and water rises

Step 7: Screed (Level the Surface)

Drag a screed board (straight 2x4 or power screed) across the tops of the forms using a sawing motion while pulling toward you. This levels the concrete to form height and identifies any low spots that need additional concrete.

Make two or three screed passes. The surface does not need to be perfectly smooth at this point --- it needs to be flat and at the correct height.

Step 8: Bull Float

Immediately after screeding, push the bull float across the surface in long, overlapping passes. Push with the leading edge slightly raised (tilt the handle down) and pull with the leading edge slightly raised (tilt the handle up). This embeds aggregate and brings the cream to the surface.

Do not over-float. Too many passes brings excessive water to the surface, weakening it. Two to three passes is usually sufficient.

Step 9: Wait for Bleed Water to Disappear

After bull floating, water will rise to the surface (bleed water). Wait. Do not proceed to finishing until the bleed water sheen disappears and the surface has a matte appearance. Working bleed water into the surface creates a weak, flaky top layer.

In Southern Utah's dry air and heat, bleed water disappears quickly --- sometimes too quickly. Watch the surface closely.

Step 10: Edge, Joint, and Finish

Once the bleed water disappears:

1. •Edge along all form edges with an edging tool to create a rounded, chip-resistant perimeter
2. •Cut control joints at your pre-planned locations using the jointing tool, pressing down to approximately 1/4 of the slab depth
3. •Broom finish by pulling a concrete finishing broom across the surface perpendicular to the primary direction of travel (for a patio, broom away from the house). This creates the textured, slip-resistant surface.

For a smoother finish (workshop floors, for example), use a steel trowel instead of a broom. Wait until the surface is firm enough that your trowel does not dig in, then make smooth, overlapping passes.

Step 11: Cure Properly

Proper curing is critical for concrete strength and longevity. The concrete must stay moist during the first 7 days of curing.

Curing methods:

• •Curing compound --- Spray-on liquid membrane that seals moisture in. The easiest method for Southern Utah's dry climate.
• •Plastic sheeting --- Cover the slab with polyethylene sheeting and weight the edges. Traps moisture effectively.
• •Water curing --- Wet the slab surface 2-3 times daily for 7 days. Effective but labor-intensive.

In Southern Utah, curing compound is strongly recommended. Our low humidity and high temperatures pull moisture from concrete rapidly. Without a curing aid, the surface dries too fast, resulting in weak, dusty, crack-prone concrete. Spray curing compound immediately after finishing and reapply if the first coat is disturbed.

Southern Utah Concrete Considerations

Temperature Management

Concrete and extreme heat do not mix well. Here is what you need to know for St. George summers:

• •Never pour concrete when air temperature exceeds 100 degrees. The concrete sets too fast, loses workability, and develops plastic shrinkage cracks. In St. George from June through September, this means scheduling pours for first light --- have the concrete truck arriving at 5:30 or 6:00 AM.
• •Hot concrete is fast concrete. Every 10-degree increase in concrete temperature reduces your working time by approximately 25%. A batch that gives you 90 minutes at 70 degrees gives you only 45-50 minutes at 100 degrees.
• •Cool your sub-base. Wet down the compacted gravel sub-base before placing concrete. Hot, dry gravel absorbs moisture from the concrete, accelerating set time and weakening the bottom of the slab.
• •Never add water to speed-set concrete. Adding water to the mix to extend working time (a common temptation) permanently weakens the concrete. If you need longer working time, ask the ready-mix plant about retarder admixture.

Fiber Reinforcement for Thermal Cracking

Southern Utah's extreme temperature swings --- from daytime highs above 100 degrees to overnight lows in the 70s during summer --- create thermal expansion and contraction cycles that stress concrete slabs. Adding synthetic fiber reinforcement (polypropylene fibers mixed into the concrete) significantly reduces micro-cracking from these thermal cycles. Most St. George ready-mix plants offer fiber as an add-on. The cost is minimal and the benefit is substantial.

Wind and Evaporation

St. George gets windy. Wind accelerates surface evaporation, causing the top of the concrete to dry before the interior, leading to surface cracking and curling. On windy days:

• •Erect windbreaks around the pour area if possible
• •Apply curing compound immediately after finishing
• •Have an evaporation retarder spray on hand for extreme conditions

Soil Considerations

The rocky, sandy sub-base material common in St. George area actually provides excellent drainage beneath concrete slabs --- water does not pool under the slab causing heave-and-settle cycles. However, ensure adequate compaction because sandy soil without compaction will settle under load.

Cost Comparison: DIY vs. Hiring Out

A 400-square-foot patio slab saves $2,000-$4,400 by doing it yourself. The materials cost the same either way. The savings come entirely from labor, which is the majority of a professional concrete bid. Equipment rental from BeeHive Rental & Sales adds $150-$300 to your total --- a small price for the tools that make the job possible.

FAQ

How thick should a concrete slab be for a patio?

A standard patio slab should be 4 inches thick, poured on a 4-inch compacted gravel sub-base. If the patio will support heavy items (hot tub, outdoor kitchen, heavy furniture that concentrates load), increase to 5-6 inches with rebar reinforcement. For vehicle traffic (RV pad, driveway), pour a minimum of 6 inches with #4 rebar at 18-inch spacing.

How many bags of concrete do I need for a 10x10 slab?

A 10x10-foot slab at 4 inches thick requires approximately 1.2 cubic yards of concrete. In 80-pound bags, that is approximately 56 bags. For anything over 20-25 bags, ordering ready-mix delivery is more practical and produces more consistent concrete. A concrete mixer rental from BeeHive Rental can help if you prefer to mix on-site.

Can I pour concrete in hot weather in St. George?

You can, but you must take precautions. Schedule pours for early morning (before 8 AM in summer) when temperatures are below 90 degrees. Pre-wet the sub-base to cool it. Ask the ready-mix plant for retarder admixture to extend working time. Apply curing compound immediately after finishing. Never pour when air temperature exceeds 100 degrees --- the concrete will set too fast for proper finishing.

How long before I can walk on or drive on a new concrete slab?

You can walk carefully on a new slab after 24-48 hours. Light foot traffic is safe after 3 days. Heavy furniture and normal use can begin after 7 days. Vehicle traffic (driving on a driveway or RV pad) should wait a full 28 days for the concrete to reach design strength. In Southern Utah's warm climate, curing proceeds faster than in cooler regions, but the 28-day rule for vehicle loads still applies.

Do I need a permit to pour a concrete slab in St. George?

Requirements vary by location and slab purpose. Standard backyard patios and shed pads often do not require permits, but driveways, attached structures, and slabs in setback areas may. Contact the St. George Building Department at (435) 627-4830 before starting. The call takes five minutes and can save you the hassle of unpermitted work.

Ready to pour your slab? BeeHive Rental & Sales in St. George has been equipping concrete projects across Southern Utah since 1994. From plate compactors for sub-base prep to concrete vibrators and bull floats for finishing, the team will set you up with exactly the equipment your slab requires. Call (435) 628-6663 for availability and rates, or browse the concrete equipment inventory to see your options.