A common truss is not normally designed to take the weight of items placed on it for storage.  Many people look at the space inside a truss and think, “I can’t waste that space for storing things”.  The reality is that the bottom cord of a truss is commonly designed to only take ten pounds per square foot which is enough to take the weight of the materials used to finish the ceiling like sheetrock, lights, insulation, and little else.  If the plan is to utilize the space in the truss, a great option is to get a storage truss, often called a “spread-web storage” truss.  This option allows a clear area for storage that is designed to take additional weight.