Air barrier paper is a synthetic material used to wrap house sheathing before siding installation to prevent water intrusion under the siding. Soffit, ridge, gable, and roof turbine vents allow airflow in and out of attics to regulate heat and humidity. A backhoe uses hydraulics to power an arm and bucket for excavation, while a bulldozer pushes objects on the ground using a broad metal head. Batter boards mark foundation lines during excavation.