A brickmason's duties are many and varied. They must read drawings and blueprints to calculate the needed materials for a structure, use straight edges to design foundations and patterns and accurately resize bricks by breaking or cutting them. Brickmasons also mix mortar or grout for spreading on a slab or foundation, lay bricks, blocks, or stones according to plans and without error build corners with corner pyramids or a corner pole. Measurements must be precise for a structure to be sound, so brickmasons also use levels and plumb bobs to make sure a structure is accurately vertical or horizontal. When a structure is complete, the mason must also clean and polish the surfaces with power tools or by hand, correct contracting and expanding joints with the use of caulking materials once settling has occurred, and clean and maintain tools and equipment.