Someone must clean that area every time the dome is sprayed. It is easy to take a shovel or a scraper and remove the excess material before it sets. After the Monolithic Dome is completed the molding is made. You will need a bag of fine sand, a bag of type I or type II cement, concrete adhesive, and a quarter round edger also known as a bull nose edger. The quarter round edger is a familiar tool used around walks and driveways.
Concrete adhesive is generally available at concrete accessory shops or lumber yards.
It is generally a white acrylic polymer under many brand names. Please follow the manufacturers directions. Remove the Excess Mix a grout mixture of two parts sand and one part cement. The mixture should have a very stiff doughy consistency. Treat the bottom of the dome wall with a concrete adhesive.