We feel all playground should be fenced to lessen the risks for the children as well as those that care for them. A fence should be at lease 4 feet or more and of a type that children can not climb. Height should be in consideration with the age and height of the children. A quality gate with a good lock is critical that children can not open. For more info note this link  or call (800) 638-2772  ask for "The Handbook For Public Playground Safety"  Regulations vary by state and should be considered for both church and private church schools as well as a guide.