Most ceiling tiles are made from mineral fiber, but other materials are available, such as fiberglass. Mineral fiber tiles typically have a high Noise Reduction Coefficient (NRC), which means they are good at absorbing sound within a space to prevent echo or loud environments.

Before lumber companies began selling OSB, the standard choice for sheathing a roof with a 24-inch rafter spacing was 1/2-inch CDX plywood - the letters CDX indicate that it is construction-grade material intended for exterior applications.

Information on the type of underlayment, flashing, shingles and ventilation being used, and the type of product and workmanship warranties offered. Proof of roofing or contractor's license (if required in your city or state).

The answer is yes, you can lay new roof shingles over old ones. But before we get started, one thing must be clear: adding new roofing over old (sometimes called a "re-roof") is possible only with asphalt shingles (also called "composition shingles").