The basic cost of any concrete pouring project will be the concrete itself. Concrete bought by the yard and delivered in a concrete truck will be priced differently than bags of ready-mixed concrete that you will have to mix yourself in a small mixer or wheelbarrow. There are a variety of online concrete job cost calculators, but each requires a cost per cubic yard figure to calculate.
Concrete costs vary not only by volume purchased, but by factors that impact the cost of manufacturing. Making concrete is energy intensive, so fluctuations in the cost of fuel for the concrete plant can make a significant difference in the cost of the finished product. Distance from sources of raw materials can make concrete more expensive in areas far from those resources than it is in areas closer to sources of limestone, sand, aluminium or iron.
Recent Typical Costs
In 2006, concrete averaged £42 to £48 per yard delivered. By 2008 prices had risen to between £55 and £65 and in 2010 prices were commonly between £78 and £97 per cubic yard delivered in full truckloads of 10 yards. As energy prices continue to rise, so will the cost of concrete.
Concrete delivered by truckloads need to meet the supplier's minimum order requirement. Standard concrete trucks commonly carry 10 cubic yards of concrete. Most suppliers require a minimum load order of 5 yards and charge a "short load" fee for anything less than a full load. A short load will always cost you a few dollars more per yard. Call your supplier and check prices once you know how much concrete you will need. As a cost saving measure many contractors try to plan jobs so they need concrete in 10 yard lots at a time or in multiples of 10 to save on short load fees. To figure the per yard cost, simply divide the supplier's price quote by the number of yards you are ordering.
Ready-mix concrete is sold in bags. The most common size bags are 40, 60 and 80 pounds. There are other sizes sold by suppliers in different parts of the country. In 2010, an 80 pound bag cost between £2.20 and £2. For each common size, a 27 cubic foot "yard" of concrete works out to ninety 40 pound bags, sixty 60 pound bags and forty-five 80 pound bags. While concrete comes in a wide variety of bag sizes, it's easy to figure the number of bags in a cubic yard with a simple calculation.
Calculating Cost With Bags
There are 27 cubic feet of concrete to the cubic yard. Divide this number by the number of cubic feet per bag as indicated on the label. Eighty pound bags hold .6 cubic feet, a sixty pound bag holds .45 cubic feet and a forty pound bag holds .3 cubic feet. Figure the number of bags per yard and then multiply the number of bags per yard by the cost per bag. If you can buy an 80 pound bag for £2.50, then multiply by 45 and you get a cost per yard of £113.40. Remember also you have to either mix it yourself in a wheelbarrow or rent a concrete mixer, which will add to your labour or costs.