 He was the pioneer carpenter at the University of Nairobi and operated a small workshop in Bahati and later on in Kaloleni.His first wife, Agnes, would help attend to customers at the Kaloleni workshop.Taking advantage of the rural-urban migration to Nairobi that resulted from the dawn of independence and the end of the state of emergency, Kirima opened bars and butcheries in Asian and African neighborhoods to cater for the growing moneyed class.