Home foundations, patios, and sidewalks all begin with concrete slabs. The method for pouring and curing a concrete slab is similar for every project. In this article, I’ll walk you through how to correctly pour a concrete slab and provide some tips to make the job a success.

    Note: Use protective eyewear and waterproof gloves when you work with cement-based products. 


    Step 1: Prepare the Site and Construct the Form

    Every strong concrete slab starts with a well-built form. First, excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete. The size of the excavated area should match the dimensions of your planned slab.

    Then construct the form with 2×4 or 2×6 lumber, and secure it in place with wood stakes and deck screws. The form boards should be straight, free of warps, and butt tightly against one another. Leave about 1.5 inches of lumber aboveground level to account for the height of the gravel and concrete.


    Step 2: Level the Form

    Next, you need to make sure that the form is perfectly level from end to end. Keep in mind that patio and sidewalk forms should slope evenly away from structures.

    This helps direct rainwater away from your home’s foundation and helps prevent soil erosion. 

    Be sure to allow 1⁄4 inch slope for every 12 feet. You can use a 4-foot level and shims to adjust the form until it’s completely level.


    Step 3: Add the Gravel Base

    A solid gravel base helps prevent uneven settling and erosion underneath the slab. Pour 3–4 inches of QUIKRETE All-Purpose Gravel or crushed stone inside the form. Use a rake to evenly spread the gravel. Compact the gravel with a hand tamper before leveling it with the top of the form.


    Step 4: Dampen the Gravel

    The gravel should be damp, but not completely soaked, during compaction. You can mist the gravel with water from a hose if it is dry but do not add enough water to create standing puddles. The finished gravel base should be solid and unmoving beneath your feet. Any soft area could lead to future settling and cracks. 


    Step 5: Pour and Spread the Concrete

    First, you will need to determine how many 80 lbs bags of QUIKRETE Concrete Mix you’ll need. You can use Quikrete’s Concrete Calculator; just enter the square footage of your slab. It may be easier for you to work with multiple smaller loads as opposed to a single large pour. 

    Use the directions on the bag to mix the concrete.

    Pour the fresh concrete into the form, spreading it as you go with a short-handled square shovel. Work the entire surface, blending the separate mounds of concrete into a flat, consistent slab. 

    For proper curing and strength, don’t exceed a 4-inch thickness on the slab. If you need a thicker slab, pour multiple 4-inch layers on consecutive days. The concrete should be 2–3 inches above the form on all sides before leveling. 


    Step 6: Level the Concrete

    Use a straight 2×4 screed board to strike off the excess concrete and level it even with the top of the form. Move the board back and forth in a sawing motion, guiding it along the form. Standing on the form boards minimizes disturbances in the wet concrete as you work. 

    Inevitably, despite careful leveling, some low spots will remain. Add a little concrete to fill any visible low areas and re-screed until level. Work systematically around the slab and screed across the narrowest sections first. 


    Step 7: Float the Concrete

    Once the concrete has lost its sheen or bleed water, it is time to smooth and compact the surface by floating it.

    You can use a wood bull float, magnesium float, or a darby for this step. Be sure to use a continuous sweeping motion when using these tools. 

    Floating presses the concrete aggregate down and brings the cream to the surface. This helps create a smooth and uniform finish. It is best to overlap each pass for the best results. 


    Step 8: Apply a Textured Finish

    Choose and apply a slip-resistant textured finish for your concrete slab. There are a few options to do this. You could use a stiff broom to create light-swept lines after you finish the float process. You can also wash off the cream on the surface to reveal the aggregate below. You may also use a stencil or stamp to finish your concrete. Finally, you can just opt for a trowel or float finish. 

    You need to apply your finish immediately after floating the concrete. This guarantees the texture will remain on the concrete after it dries. 


    Step 9: Cut Control Joints and Edge the Concrete

    All concrete slabs will crack over time as the material shrinks and expands.

    Control joints are placed in the concrete to help control where cracks will occur. You will need a groover to create these joints. You will need to cut the joints within 24 hours of the pour. Space the joints every 8 to 12 feet along the slab. The joints should be approximately ¼ the depth of the slab, so 1 inch for a 4-inch thick slab. 

    Use an edging tool to shape the slab’s edges. Make several passes in each direction for a smooth finish. 


    Step 10: Allow the Concrete to Cure

    This is the final step in the process and the one that takes the most time. Cover the slab with plastic sheeting to hold in moisture. For best results, water-cure the slab with a sine mist at least twice a day for 5–7 days while the concrete cures. The exact time it will take for the concrete to dry depends on a variety of factors, including the temperature, humidity, and size and type of concrete. 

    Today’s Homeowner Tips

    Instead of water curing, you can also apply QUIKRETE Acrylic Cure & Seal after finishing.

    To learn more, visit www.quikrete.com.


    So, Is Pouring a Concrete Slab a Good DIY Project?

    Hiring a professional concrete contractor is highly recommended for pouring slabs‌. Pro crews have the workforce, tools, and expertise to properly handle, place, and finish concrete. They can also assess whether any permits are needed and will be experts on local building codes. Pouring concrete slabs is also very labor-intensive, and working with concrete leaves little room for error. Any mistakes in pouring concrete will be permanently set in the slab. 

    That said, a seasoned DIYer could certainly learn the skills necessary to pour a concrete slab. Plenty of research, the right tools, and attention to detail are required if you are looking to DIY your next concrete project. I do recommend starting with small projects or simple slabs to avoid getting in over your head. For example, a simple slab like a small concrete patio would be a manageable starter project. 

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    FAQs About Pouring Concrete Slabs

    How long does poured concrete take to cure?

    Concrete cures over 5–7 full days. It is best to avoid walking on the slab for at least 48 hours after the pour. The slab will reach about 70% strength in 7 days, making it safe for vehicles to drive on,  and 100% strength after 28 days.


    Can I pour concrete in hot weather?

    It is possible to pour concrete in hot weather. You’ll just need to take proper precautions against rapid surface drying by misting the concrete regularly after finishing. Anything above 80 degrees Fahrenheit would be considered hot conditions. It is best to pour your concrete early in the day before peak heat. You should also chill the mixing water and aggregate for best results in extreme heat.


    What PSI should concrete be for a slab?

    For most home improvement projects, your concrete should be at 3,000–4,000 PSI strength. This is an appropriate strength that achieves good workability for placing and finishing. If you require stronger concrete, you can use additives to increase the strength.


    How thick should a garage concrete slab be?

    Standard garage slabs are 4 to 6 inches thick. However, depending on your soil, the slab size, expected vehicle loads, and local building codes, you may need a thicker slab. It is best to consult a structural engineer for recommendations.


    Can I pour concrete directly onto the ground?

    No, poured concrete requires a 4-inch gravel base under the slab perimeter and interior to prevent cracking and shifting. The base isolates the slab from ground moisture.



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    Nikki Stavile

    Nikki Stavile is a writer based in Tucson, Arizona. As an avid backpacker and passionate environmentalist, her work often focuses on sustainable movements at the personal and societal level.

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    Casey Daniel

    Casey Daniel is a writer and editor with a passion for empowering readers to improve their homes and their lives. She has written and reviewed content across multiple topics, including home improvement, lawn and garden care, sustainability, and health and wellness. When she’s not reviewing articles, Casey is usually playing board games, repainting her bathroom, or quilting.

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