Builders Level Video
Your project calls for a level line around the entire room. This line would be needed for crown molding or a suspended ceiling. How do you do this? Using a 4 foot level and drawing a line around the room is time consuming and can lead to errors.
A better method is to rent a builder's transit or builder's level. This tool sets up on a tripod and uses bubble levels to get the instrument level in the room. Sighting through the level, mark the wall at the required height. A helper will be required to make the marks. Once the marks are created around the room, use a chalk line to create your line.
These builder's levels are easy to use and can be rented at most tool rental stores.
Tim built custom homes and did ultra-custom remodeling for 20+ years before launching his Ask the Builder media presence. He was selected as one of the Big 50 by Remodeling magazine in 1993. This award gave birth to Ask the Builder in October 1993. Tim also operates https://DrawPlumbingPlans.com. His @askthebuilder YouTube channel was the first home improvement channel on YouTube.