One does not have to be a structural engineer to know that a crack anywhere on a building is not a good sign. Aside from being ugly, cracks can cause a lot of damage to a property that do not necessarily have to do with the structural stability of a structure. The truth of the matter is that cracks come in all shapes and sizes and depending on many factors, can hint at a serious issue or are merely unsightly and can be repaired rather easily.
Cracks that are not structural
Having performed thousands of inspections as a structural engineer, I can
categorically state that the majority of the cracks I have seen are not serious to the point where a structural emergency repair is necessary. That is not to say that you can relax and ignore any crack. If you decide to ignore a crack on your house, you are risking that the crack is indeed serious and it could eventually lead to a safety risk.
There are many types of cracks that have strange-sounding names such as "crazing" and "shrinkage". I will try to keep this blog at a layman level and do muy best to explain some of the more common types of cracking that the common person is exposed to.
The most common type of cracking is what I would call a "surface crack" because it is of little structural consequence and it is basically what the name denotes. The origins of these cracks are varied but many times has to do with the manner in which the stucco is applied to the surface or the manner in which the plasterer mixed the stucco (maybe with too much water in the mix). If you look t most properties closely, you will see these types of cracks somewhere. These cracks are not serious in the sense that the structure will collapse. These cracks, however, are serious in the sense that they could allow water and moisture into the property and damage the interior or allow insect infestations. These cracks can be repaired by applying an exterior grade spackling you can buy at your local hardware store, or by merely painting the property and maintaining it throughout the year.
Cracks that are structural
Concrete structures are designed by engineers to withstand outside forces. When a building is subjected to forces that the property was not designed to withstand, then cracks will inevitably appear. These outside forces include, but are not necessarily limited to, hurricanes, earthquakes, loads imposed by the occupants, snow, and settlement of the soils underneath, just to name a few.
Here in Florida it is common to see cracks at the corner of a house that are diagonal. An experienced engineer will be able to identify the type of crack and, depending on the severity, provide a solution to deal with the problem. Other cracks can appear next to a window or at the uppermost beams that are located adjacent to the roof structure. These types of cracks are easy to point out, but are more difficult to diagnose and provide solutions for.
Structural cracks are a serious matter since they can become worse over time and eventually render the structure unsafe. Engineers employ different investigative techniques and tools to diagnose different structural failures, but nothing compares to the experience the engineer has. While it is not in the scope of this blog to educate the reader about all the different types of cracking, their seriousness, and their consequences, it is important to note that hiring a structural engineer to look into it is of utmost importance.
If you suspect that there is a crack on your property, I strongly suggest that you seek out a local structural engineer to take a look at it. Depending on your area, an inspection and a report will cost you between $200 to $500. The report should contain the engineer's observations, his conclusions, and recommendations on what the next steps should be. If it is indeed a serious problem, the engineer should tell you right there and then.