If you have clay or loam soil, you should remove enough to allow a 6- to 8-in. layer of compacted gravel under the new concrete.
How Much Topsoil to Remove for Concrete?
Installing a concrete slab is a great way to add a functional outdoor space to your property. But before you can begin pouring the concrete, you must first remove any topsoil that is present. The amount of topsoil to be removed is dependent on the size of the area you are pouring the concrete and the type of soil present.
When removing topsoil for concrete, the general rule of thumb is to remove a minimum of 2 inches of topsoil. However, this may vary depending on the type of soil present. For example, if the soil is clay-based, it may be necessary to remove more than 2 inches. Additionally, if the area is large, it may be beneficial to remove more than 2 inches of topsoil to ensure a solid foundation for the concrete.
Once the topsoil has been removed, it is important to dig down to the required depth for your concrete slab. Standard concrete slabs are typically 4 inches thick, so you will need to dig down at least 6 inches to provide a solid foundation for the concrete. It is important to note that if your soil is predominantly clay, it may be necessary to dig down further than 6 inches to ensure a solid foundation.
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