If you could compact the rock adequately there’s no reason it couldn’t work but appropriate concrete base is so cheap, and cracked concrete such a pain to repair that it makes no sense not to use exactly the base intended for the purpose.
What is the best base for concrete slab?
What Material is Used for a Slab Base? 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.
What do you put under a concrete slab?
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.
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.
What do you put under lava rocks?
The best defense against weeds growing in lava rock is landscape fabric. The fabric allows air circulation and water penetration but blocks most types of weeds from sprouting without the need for chemical herbicides.
Do you need gravel under a concrete slab?
You do need gravel under a concrete slab, footing, or patio. Gravel provides a solid foundation for your concrete as it can be compacted. It also improves drainage, preventing water from pooling beneath the concrete.
Do I need a sub-base for a concrete slab?
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.
How many inches of gravel do you need for a concrete slab?
Excavate the soil to a depth of 8 inches, allowing 4 inches for the gravel base and 4 inches for the concrete slab.
Does a 4 inch slab need rebar?
No, rebar is not required for a 4-inch slab of concrete on grade. A 4-inch-thick slab cast on the ground and in constant touch with it will float, with no need for rebar. For concrete that is 5–6 inches thick, rebar is suggested.
What type of gravel is used for concrete?
Gravels constitute the majority of coarse aggregate used in concrete with crushed stone making up most of the remainder. Natural gravel and sand are usually dug or dredged from a pit, river, lake, or seabed. Crushed aggregate is produced by crushing quarry rock, boulders, cobbles, or large-size gravel.
How long does lava rock last?
Lava rocks should last for around two years before they start to show signs of wear. Keep using them in your fire pit until you notice them getting a little crumbly looking.
What happens if lava rocks get wet?
Lava rocks are very porous like a sponge. Water can get trapped inside of lava rocks when they get wet. When the wet lava rocks get heated up by the fire, the water inside turns to steam and expands. This creates pressure inside of the lava rocks which can cause them to explode open.
How deep should lava rock be?
They also tend to be heavy enough that they won’t blow away during storms or when using a leaf blower. We do recommend placing the stones either 1 inch below the ground’s surface or using an edging material to avoid displacement in areas with heavy foot traffic.
Why do you put crushed rock under concrete?
Having a gravel layer helps keep the slabs even, prevents cracks, helps with water drains and helps avoid low spots within the subgrade. The subbase is literally the foundation and with it, you don’t have to worry about the subgrade material.
Can I pour concrete directly on dirt?
Long story short, yes you can pour concrete over dirt.
What size gravel is best for concrete?
Gravel for Concrete
Depending on what the driveway will be used for, the base may need to be 4 to 12 inches. Ideally, 6 inches of crushed stone or gravel should be used for most driveways.
How deep 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.
How do you make a concrete pad?
Quote from Youtube video: Begin installing either wood or metal stakes placing them 2 or 3 feet apart on all sides. Next. You'll want to determine the height of your slab. Simply pick an elevation at one corner.
How do I prepare the ground for my garage slab?
Good ground preparation starts with removing the topsoil. Then, if the soil has not previously been “disturbed” (i.e., dug up), a four-inch layer (minimum) of gravel or stone should be added. (Soil that has been dug up before should be compacted.) The gravel or stone also needs to be compacted.
How much does it cost to pour a 24×24 slab of concrete?
A typical 24×24 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.
Does a garage slab need rebar?
A garage slab or the garage concrete floor does not need rebars, provided it is 4” or less in thickness. Other forms of concrete reinforcement will however reduce cracks. Rebar is certainly required if the garage slab is 6” or thicker. This is the short & sweet answer.
