If you are planning on using a large amount of concrete and don’t want to spend your time mixing hundreds of concrete bags by hand you may want to hire a concrete truck to deliver a few yards of ready mix concrete to your site. This will be somewhat more expensive but you can be sure that the concrete is properly mixed and it will save you a large hassle of doing it yourself.
There are several different mixes available. Tell the ready mix company what you are using it for and they should be able to recommend the best mix. You will want to make sure that the concrete you are buying yields a compressive strength of at least 2500 psi. Concrete is sold by the cubic yard. You can use the calculators on Decks.com to determine how much you will need to order. Make sure you allow for at least 10% extra so you don’t run short. There is usually a minimum of 1 cubic yard limit for orders and a delivery surcharge. Make sure to have the site prepared for the concrete delivery so as not to waste their time, some ready mix companies will even charge for delays.