Backfill the hole with dirt/fill to about 10-12″ below the surface. You should compact the soil frequently as you go – don’t wait until the end. Wetting it will help compact it. After the soil add 6-8″ of 1/2″ crushed gravel.
What do you fill holes with before concrete?
Most holes can be fixed with a quality mortar mix, although you should use one with a crushed stone aggregate to fill holes over 1 in (2.5 cm) deep. Treat holes as soon as you find them so you can prevent water and rodents from further damaging the concrete and getting into your home.
Can you pour concrete directly in hole?
The reason we don’t recommend pouring concrete in a hole full of water is that concrete can actually set under water – and not just concrete, the aggregate as well. If you look at the density of the three (water, concrete, and aggregate), you will find that aggregate is the first to settle.
How do you fill a large hole in the ground with concrete?
How to fill a Large Hole with Concrete
- Step 1: Use a hammer and a cold chisel to level the bottom of the hole. …
- Step 2: Brush on a concrete bonding liquid. …
- Step 3: While the bonding agent is still tacky, mix the concrete. …
- Step 4: Level the patch.
Do you need gravel under concrete?
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.
What kind of gravel do you put under concrete?
crushed stone
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.
Can I pour concrete directly on dirt?
Long story short, yes you can pour concrete over dirt.
Is sand a good base for concrete?
As a general rule, stay away from using sand as a subbase. You’re better off using gravel; your concrete will last longer and have less of a chance of cracking over time.
How do you pour concrete in a small area?
Quote from the video:
Quote from Youtube video: Dampen the area and then simply pour the contents of the bag into the shuttering. And level off with a straight edge. Like a trowel or a piece of wood.
What happens if you don’t put gravel under concrete?
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.
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.
Can I pour concrete over gravel?
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.
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.
How much sand and gravel do I need for a yard of concrete?
An average 1:2:3 mix contains one part cement, two parts sand and three parts gravel. To make 1 cubic yard of concrete, you’d need seven 94-pound bags of cement, about 1/2 cubic yard of sand and just over 3/4 cubic yard of gravel.
What area will 1 ton of gravel cover?
approximately 100 square feet
A ton of gravel will cover approximately 100 square feet, 2 inches deep.
Can I just use cement without sand?
While sand is the most common aggregate used to create concrete, you can also mix cement with gravel, crushed stone or even pieces of old concrete.
