Are All Hollow Blocks the Same? Many homeowners think hollow blocks are all equal. They may look similar from the outside, but their quality can be very different. Concrete Hollow Blocks, commonly called CHB, can vary depending on thickness, mix ratio, curing, handling, and actual strength. A weak hollow block may crack, absorb moisture, or fail under pressure. That is why before building your home in Cagayan de Oro, it is important to check if your walling material matches t