Essential Functions You must be able to twist, stoop, bend, squat, kneel, crawl, climb ladders, climb stairs, walk on uneven ground, work above ground on scaffolds, have depth of perception to avoid excavations and other hazards, hear well enough to recognize the sounds of horns and sirens on moving equipment and have good finger manipulation. Structural Framework Construction : Accurately measure, cut, and assemble wood and other materials to build strong, reliable frameworks for walls, floors, and roofs in accordance with blueprints and building codes.