What caused the cracks?

Q. My daughter and son-in-law are looking for a house, and they found one we all think is “the one.” Problem is, there are cracks in the outside wall, and I think they go all the way through, but there’s paneling on the inside, so I can only see in one spot. The cracks are in the same place on both sides of the house. I don’t think the soils are in any kind of water. What causes this, and can it be repaired? Is it going to be too expensive?

A. Your question is timely, since, as I reply, another concrete pour is about to begin for a client’s project. I’ve been back and forth to the site five times this week just to inspect the location of reinforcing rods. I rejected the work, twice, because the steel rods’ diameters were too small and they weren’t placed where the plans and calculations required. The contractor was surprised that I even went to the site. He told me that no architect ever comes out; they just trust that the concrete subcontractors know what they’re doing.

At that point it becomes a matter, on my part, of diplomacy to explain that I’m hired to check details, not just draw them. It would be like going through the entire prenatal care with a doctor and having him not be there for the delivery of the baby. I tell you all this because, in my long career, I’ve seen hundreds of mistakes in location of the steel or even leaving out the steel. Those steel rods are the backbone, the spine, of the foundation. They keep concrete stable in tension — or, in layman’s terms, they allow the concrete wall to have a little flex without cracking, since concrete has no ability to absorb being pulled apart without giving way. Concrete can be pressed, called compression, to a high degree, taking thousands of pounds to crush, but a small amount of sideways or upward movement makes the walls pull apart, which you’re noticing.