Question 1

How much does a concrete slab cost per square foot?

Accepted Answer

On average, a residential concrete slab costs between $6.00 and $12.00 per square foot installed, including materials, site preparation, base gravel, reinforcement, forms, and finishing labor. DIY projects with material only cost approximately $2.50 to $4.50 per square foot.

Question 2

How much does a 10x10 concrete slab cost?

Accepted Answer

A 10x10 foot concrete slab (100 square feet) at a standard 4-inch thickness costs between $600 and $1,200 professionally installed. It requires approximately 1.23 to 1.35 cubic yards of concrete (around 28 bags of 60-lb or 21 bags of 80-lb concrete mix including waste).

Question 3

How much does a 20x20 concrete slab cost?

Accepted Answer

A 20x20 foot concrete slab (400 square feet) typically costs between $2,400 and $4,800 installed for a 4-inch slab, and $2,800 to $5,400 for a 5-inch or 6-inch garage slab. It requires approximately 5.0 to 5.5 cubic yards of ready-mix concrete.

Question 4

How thick should a concrete slab be?

Accepted Answer

Standard non-traffic patios, walkways, and shed floors require a 4-inch slab (minimum 3,000 PSI). Residential driveways and 2-car garages accommodating SUVs and trucks require a 5-inch or 6-inch slab (3,500 to 4,000 PSI) with rebar reinforcement. Heavy RV pads or commercial slabs require 6 to 8 inches.

Question 5

Is ready-mix concrete cheaper than bagged concrete?

Accepted Answer

For projects requiring more than 1.5 to 2 cubic yards (approx. 70+ 80-lb bags), ready-mix delivered by a transit-mix truck is almost always cheaper, faster, and provides superior compressive strength consistency compared to hand-mixing bags.

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