The very nature of concrete often makes it impossible to eliminate cracks entirely. The extent and severity of these cracks, however, vary widely in the field. Concrete cracks that are infrequent, tight, and do not spall are hardly ever objectionable. On the other hand, when they become extensive, wide and unsightly, they can constitute a very real problem. The result can be trouble and hard feelings for all involved. Let's take a quick look at some of the factors which influenced cracking of concrete. (1) Restraint: if conditions set up forces in concrete which alter its dimensions or position and it is restrained, the result is a crack. (2) Mix design: as when the mix is too soupy. (3) Reinforcement: if reinforcement is used for structural purposes, the size and position will differ from that used to control thermal and drying shrinkage cracks. And (4) placing and finishing: because concrete almost always hardens eventually- despite the many ways it nay be misused- the importance of proper placing, finishing, and curing procedures is often overlooked. Well compacted concrete, on the other hand, is less likely to crack. Scientists have been at work for decades trying to develop crack-proof concrete. However, until a low-cost, high-performance, crack-free concrete is developed, it is suggested that the following rules be followed. (1) Design the member to adequately handle all anticipated loads. (2) Provide proper shrinkage and isolation joints. (3) In slab on grade work, prepare a stable subbase. (4) Provide correct reinforcement at proper level. (5) Order concrete reinforcement at proper level. (6) Place and finish according to established standards. (7) Cure the concrete thoroughly.