Can I pour concrete over rock?

Big rocks are not a problem as long as there is uniform concrete coverage and adequate rebar for temperature fluctuations. If the big rocks protrude up above grade and if you have a few in a row, it will weaken the slab. We like things uniform, including the grade, thickness of the concrete, etc.
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Can you lay concrete over rock?

Because concrete is a very porous material, it will absorb any moisture that it contacts. This can cause pooling. Without crushed stone, pooling water will settle under it and erode your slab. Adding a layer of crushed stone will add proper drainage, as well as create a barrier between your slab and the ground.
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Is it OK to pour concrete over gravel?

Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel is especially important in clay soil because it doesn't drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains.
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Can you pour concrete over rock driveway?

Cement mix might work in some cases over an existing gravel driveway. Laying a concrete driveway over an existing gravel one is possible, but it is not generally recommended. The kind of gravel that is intended to go under cement is typically a smaller grade than what is used for gravel driveways.
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Whats the difference between cement and concrete?

What is the difference between cement and concrete? Although the terms cement and concrete often are used interchangeably, cement is actually an ingredient of concrete. Concrete is a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement.
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brushing CHEAP concrete onto a gravel driveway (adding strength and resilience)



What happens if you don't put gravel under concrete?

The most major benefit, though, is drainage. Water that seeps beneath a slab can erode soil, causing gaps between the earth and slab. Those voids cause cracks, destabilizing your concrete slab. Compacted gravel allows water to escape and travel into the earth without pooling.
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How do I turn my gravel driveway into asphalt?

An inexpensive method for paving a driveway consists of gravel or crushed rock over a graded, packed dirt bed. If you already have a gravel driveway and want to pave over it, the least expensive option is adding a hot-asphalt seal-coat layer over the surface of the gravel, followed by a layer of crushed rock.
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What kind of stone goes under concrete?

The base in concrete construction is usually a form of crushed stone. Most concrete contractors want a mix of coarse and fine aggregate to create a compactable base that is going to be safe for settlement and drainage.
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Can you pour concrete over aggregate?

If done properly, new concrete can often be poured right over an existing slab. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete.
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Can I pour concrete directly on dirt?

Long story short, yes you can pour concrete over dirt.
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How many inches of gravel do you need for concrete?

Excavate the slab area to a depth of about 7 inches, allowing 3 inches for a gravel base and 4 inches for concrete.
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How many yards of concrete do I need for a 24x24 slab?

For example, for a concrete slab that is 24' X 24' X 4”, simply enter 4 in the Thickness/Depth field, 24 in the Width field, and 24 in the Length field. Click “Calculate”. Your answer should be 7.11 yards. Note: The Concrete Volume Calculator can also be used to determine yardage for aggregate products.
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Do you need a subbase for concrete?

Subbase for Concrete Slab

The subbase placement is optional and it serves as a work platform for construction of the slab and provide more uniform support for the slab. As the thickness of subbase increases, the ultimate load carrying capacity of slab increases.
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How do I make my gravel driveway more solid?

How to Stabilize a Loose Gravel Driveway
  1. Remove organic matter from the driveway. Tree limbs, leaves and mud can end up on the driveway. ...
  2. Fix any drainage issues. Look carefully at your driveway after a rain. ...
  3. Fill potholes and other low spots. Most gravel driveways develop low spots over time. ...
  4. Compact the gravel.
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How do you make a gravel stable?

The two most effective methods for stabilizing pea gravel are cement and permeable pavers. If you're stabilizing pea gravel with cement, it will hold for a while until it's eventually damaged by traffic and water exposure.
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Does crushed concrete make a good driveway?

Along with being an impressive and reliable driveway surface, crushed concrete can also be used in landscaping projects, construction, and much more. Use it for your driveway first, and you may get ideas for other ways to use it around your property.
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Do I need plastic under concrete?

Plastic is a moisture barrier generally to stop ingress from beneath the slab. If this is outdoor in an exposed area it probably doesn't matter. I'd probably use plastic if the area is moist with little sun, just to alleviate any algae growth. It's outdoors, north facing, lots of sun.
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How thick should a concrete slab be?

Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.
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Do you need a moisture barrier under concrete?

If you have a concrete floor that's in continuous contact with a source of moisture, you're going to have problems. This is why a vapor barrier under concrete is essential. Vapor barriers are a way to keep moisture from getting into the concrete.
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How much does it cost to pour a 24x24 slab of concrete?

A typical 24x24 garage slab costs between $3,057 and $5,944 with prices ranging from $5.31 to $8.31 per square foot for a 4” reinforced slab of concrete, and $6.83 to $10.32 per square foot for a 6” slab of reinforced concrete.
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Is cement cheaper than concrete?

First, it's more economical. Rock and sand are cheaper than cement alone, so mixing them in makes concrete cheaper than pure cement. But that rock and sand isn't just filler. Those components make concrete significantly more durable than pure cement.
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Which is stronger cement or concrete?

Let's start with the basics: concrete is significantly stronger than cement. Cement is a durable material in its own right, but it simply does not compare to concrete. That's why cement is usually used for smaller, more decorative projects.
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