Re: Concrete Patio
To add to Sprucey's post ---- there isn't a mention of what area you're in ------ If there will be frost heave or not.
Preperation is a main factor to the longevity to the pad.
A proper sub-base is critical ---- especially with clay soil and / or ground frost.
It's a good idea to excavate away any top soil along with any other organics like roots and get down to good layer of clay .
Place a geo-texitle ( heay land scape fabric ) down on top of the clay to seperate 6 - 12 inches of 3/4 down stone base , from the soil ---- don't use plastic the fabric allows ground water to pass through.
Rent a vibrating compactor and run it over the 3/4 down stone.
Lay the rebar or mesh and pour the concrete.
"" an ounce of perception -- a pound of obscure "