Installing Concrete
The term "set in concrete" implies permanence, so pouring concrete is one of the most important home improvements to do right the first time, because no one would want to have to do it over again. Most consumers hire a professional, licensed concrete contractor to add concrete to their property because professionals are usually best equipped to know how much of what kind of concrete is needed, and will be responsible for having it properly delivered and finished.
However, there may be times a homeowner may choose to have the concrete delivered directly, perhaps to pay the concrete delivery company separately from the contractor, or because he is confident he can finish it himself or with help from other non-professionals.
It is important that the site is prepared before the concrete truck arrives, including all forms set and the ground properly leveled and moistened, if necessary. Concrete delivery companies may schedule several pours in a row and will charge extra if the driver has to wait idle on any site because it is not ready for the pour.
If concrete is to be poured where the delivery truck cannot reach, the concrete will need to be carried by wheelbarrow or pumped by an independent concrete pumping company if it is too much to wheelbarrow. This is usually coordinated by the contractor or the concrete delivery company.
The proportion of mix to water must be right in order for concrete to be strong enough for its application. Foundations require less water than flat slabs, for instance. Concrete does not "dry" but cures. Usually, the more slowly concrete cures, the stronger and less likely it will be to crack. Usually water must be sprayed on poured concrete several times a day for up to a week to make sure it does not cure too fast. It's also important that the soil under poured concrete is wet so the dry soil does not absorb water from the concrete, causing it to cure too fast.
No matter how well concrete is poured, however, no contractor can guarantee concrete will never crack. Tiny surface hairline cracks are not uncommon and will not affect strength or performance of finished concrete.
-- Tips courtesy of HomeAdvisor.com