Remove all movable objects, such as furniture, from the room. Turn off the electricity and air ventilation systems due to the excessive water used in this project.
Cover the air vents, electricity outlets, light switches, floor and walls with plastic floor sheeting. Seal the sheets with blue painter's tape. Lay resin paper over the floor for simple clean up.
Fill a garden sprayer with 1 gallon of warm water and 3 tbsp. of dishwashing soap. Thoroughly combine the soap solution.
Put on a dust mask and safety glasses to protect you against airborne dust.
Spray the soap solution onto a 4-foot section of the ceiling to loosen the popcorn. Moisten with popcorn without over-saturating the underlying drywall. Let the solution permeate the ceiling for 20 minutes.
Scrape off the wet portion of popcorn texturing using a putty knife. Try not to puncture the drywall. Soak the ceiling with more soap solution if the popcorn is unyielding in some areas.
Soak and scrape each remaining individual 4-foot section of the ceiling until all popcorn texturing is removed.
Remove and dispose of all plastic sheeting and resin paper. Turn on the electricity and air ventilation systems.