Carpenter who works for a general contractor often must perform many tasks common in new construction. Carpenters read blueprints and receive instructions from Customers. They determine the dimensions of the building and the materials to be used. They lay out, measure, and mark the wood or other materials, using measuring tapes and squares. Carpenters cut or shape the wood, using hand and power tools. They join and assemble the materials using nails, screws, staples, or glue. They check their work for accuracy, using levels or framing squares. Generally carpenters build components, such as floors, stairs, or wall panels or install ones that were built off-site.