20×24 Concrete Slab (6 inches): Yards, Feet & Bags
This 20 ft x 24 ft concrete slab, at 6 inches thick, works well for a driveway section or a shop floor. Decide between using bags or ready-mix based on your delivery access and project scale.
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Quick Answer
Tip: Always confirm the yield printed on your bag label. Bag yield guide
Large pour: consider ready-mix delivery for speed and consistent results. Bag counts this high can take significant mixing time.
Project Notes (Unique)
For accurate ordering, round to 0.25 yd³ and check yield on the label to ensure you have enough material.
Ensure your base is well-prepared and forms are sturdy to prevent shifting, especially if you're adding thickened edges.
Apply a smooth finish, and keep the slab moist during curing to enhance strength and durability.
How to Estimate This Slab in 3 Steps
Measure
Length 20 ft, width 24 ft, thickness 6 in.
Compute Volume
Area: 480 sq ft → volume: 240.0 ft³ → 8.89 yd³.
Add Waste
Add a small buffer for spillage and uneven subgrade, then round up when ordering.
Planning Notes
Common uses: driveway section, shop floor, large patio.
For more context and conversions, see the Concrete Calculator hub.
Frequently Asked Questions
What is the best option for mixing concrete: bags or ready-mix?
Ready-mix is often more convenient for larger projects, while bags can be useful for smaller areas or DIY jobs.
How do I determine the right thickness for my concrete slab?
Consider the intended use; heavier loads may require a thicker slab for added strength and stability.
What should I do to prepare the base before pouring concrete?
Clear the area of debris, ensure a level surface, and compact the soil to provide a stable foundation for the slab.
How much extra concrete should I order?
It's wise to order a bit more than estimated to account for spillage, over-excavation, or miscalculations.
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