Holding the equipment at the wrong angle and using the wrong type of sand are two of the top problems with sandblasting concrete. The sandblaster's wand needs to be held 18 to 24 inches and at a 45-degree angle, the sand should be consistent in size. To accomplish this, a silica sand is commonly used.
Other problems when sandblasting can come up with the county via the neighbors. Sandblasting is extremely noisy, so neighbors are likely to complain. As a good measure, many people inform neighbors ahead of time.
Sandblasting is also very messy. Wet-tip sandblasting can make the process less messy but also slow down the sandblasting. In some counties this is required or else there is a risk of being cited for interfering with traffic visibility. Dust ends up everywhere, so windows need to be sealed heavily. This is another problem neighbors need be aware of.
The last problem of sandblasting concrete, is the heavy amount of precleanup that is required of the concrete surface. The concrete and surrounding area needs to be completely free of any debris. Items such as tree branches, little pebbles, rocks, acorns and any hard item all become fast-flying objects when hit by a sandblaster. The outcome could be bad for the homeowner, especially if the injured party was a neighbor.