Pavers vs. Concrete
Alatini Saulala describes the advantages of pavers over concrete for a patio.
For a patio, Pavers are the way to go for a number of reasons
At a later date you can add to or change the layout
No problem with cracking. If you think cracking may not be a problem with concrete - look at some of the work done by pros
Access to site - you do not want a ready mix truck on your lawn.
Weed contorl is easy - vegetation barrier below and period crack treatment for wind borne weeds
Pavers on a sand base are easy to install and forgiving if you miss a level.
Water drainage - water will drain thru the base sand. With concrete ,the slab must be carefully sloped in the direction you want the water to go.
Coloring concrete is problematic. Pavers come in many permanent colors and shapes.
Running power and water (you are installing a grill?? or maybe a hot tub??) is much easier with pavers.
If after all of this you do decide to use concrete consider:
Be sure the base material drains well
Be sure to use 4 inch by 4 inch welded wire mesh and not less than 3.5 inches of concrete. The concrete must be thicker if you plan to park a vehicle on it.
Be sure your welded wire mesh is flat (it comes in rolls) before you place it in the concrete form.
When the mesh is in the form be sure it is suppported with "chairs" (stones) to keep the concrete from pushing the mesh to the bottom of the pour. Ideally you want your mesh in the middle of the thickness of the concrete.
Do not over work the surface - if you do, you will get excess fines to the surface and in time they will spall and ruin your job.
be sure to put in control joints (gooves when concrete is setting up) to minimize surface cracking
Do not allow the surface of the concrete to dry to rapidly - cover with plastic or the like
Be sure to round the perimeter edges while the concrete is setting up. This is necessary to prevent corner chipping.
If the slab edges are to exposed, remove the forms before the concrete has completely set up and use a mortar mix to fill in voids in the edges.