I had the opportunity to watch a team of professionals install a Stamped Concrete Patio. Working with concrete in itself is an art, but adding the stamped concrete aspect shows that they are truly artists. If you are considering putting in a patio, I would recommend a stamped concrete patio after seeing the results of this process. I took some pictures along the way and this article is a chronicle of how they did it. The first thing that was done was to excavate the area removing the dirt and tree roots in the area so that a substantial gravel base can be laid on the dirt. In this case there is about 8 inches of compacted crushed stone on top of the dirt. This was done prior to the pictures here, but several factors go into how much gravel you will need including the depth of the frost line (colder locations need more to prevent heaving in winter), amount of concrete that will be poured, and where the top of the finished patio will be. Since this installation was connecting to an existing driveway, the finished top was expected to be level with the driveway.
The company doing the installation had put the edging around the patio where the concrete will be poured and placed re-bar in that area, which will strengthen the concrete once it is dry. The long bar going from the left to the right of the photo is a concrete screed that will be used to flatten and level the concrete over a large area once it is poured.
The concrete that was poured for this patio is about 3 inches thick and it is about 14 feet wide by 14 feet long. It took 6 1/2 yards of concrete to fill the area. A concrete truck (the ones with the big rotating cylinder on the back) showed up for the pour, which made things easier. For the furthest areas away from the concrete truck, the men used wheelbarrows to haul the concrete from one side to the other. After the patio was about 2/3 full of concrete, they dumped it directly off the concrete truck into the patio.
You can also see the screed in this picture where they have already screed the concrete in half the patio. At the same time as they are pouring the concrete, they begin to float it. This process uses a flat bar on a long pole that they drag over the concrete to smooth it out.
Once the whole patio is poured and floated, they wait for the concrete to cure for a little while. The concrete is still wet, but it has hardened to where it is like soft pudding. At this time, they spread a colored release over the top of the concrete. This will keep the stamps from sticking to the concrete when they are removed. It will also give the concrete some color. In this picture, the color looks a little purple. The color that is a result is actually a grey, but this will not show until the concrete has dried and been cleaned.
After the release is put down, they lay out the stamps and push them into the concrete. The stamps are large rubber mats that have the pattern embedded in the underside. They have non-square edges that fit together like a jig saw puzzle. They lay out 4 or 5 of these stamps, press them into the concrete, then move the first ones to the next space and lay them out until the whole patio has been stamped.
Once the whole patio has been stamped, they let the concrete dry overnight.
The following day they return to detail the patio. They clean off the leftover release, grind out the cracks where the edges of the stamps met up and cut relieve joints all the way across the patio in the shape of a cross. These will allow the patio to expand and contract, and any cracks that may happen will happen in these joints so the entire patio will not crack. Finally they paint the grooves where the stamps met up and put down a sealer on the concrete and that is all! In all the first day took about 4 hours to complete where about an hour was waiting for the concrete to set up enough for the stamps to be put down.