Question 1

How many bags of concrete do I need?

Accepted Answer

An 80-lb bag yields about 0.6 cubic feet (0.022 cubic yards). For a 10x10 ft slab 4" thick, you need about 1.23 cubic yards = ~56 bags of 80-lb concrete.

Question 2

How much does a yard of concrete cost?

Accepted Answer

Ready-mix concrete costs $125-175 per cubic yard delivered. Bagged concrete costs more per yard but is practical for small projects under 1 cubic yard.

Question 3

When should I use bags vs. ready-mix?

Accepted Answer

Use bags for projects under 1 cubic yard (small slabs, post holes). For 1+ yards, ready-mix is more cost-effective and ensures consistent quality.

Question 4

How long does concrete take to cure?

Accepted Answer

Concrete reaches 70% strength in 7 days and full strength in 28 days. It can be walked on after 24-48 hours and driven on after 7 days.

Question 5

How thick should a concrete slab be?

Accepted Answer

Sidewalks: 4". Patios: 4". Driveways: 4-6". Garage floors: 4-6". Foundations: 8-12". Always check local building codes.

Strength (PSI)	Best For
2,500 PSI	Sidewalks, patios, non-structural
3,000 PSI	Driveways, foundations, general construction
3,500 PSI	Structural, garage floors, footings
4,000 PSI	Heavy traffic, commercial, parking
4,500 PSI	Post-tension slabs, high-strength structural
5,000 PSI	Bridges, heavy industrial, high-rise

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