Silas was the 3rd son of Simon Ngige Wainaina and Jacinta Wangui Gatuguta of Matunda , Kitale in Uasin Gishu, and brother to Boniface Wainaina (late),Robert Ndungu, Brian Njuguna and Sammy Ngige. He was a loving father to Joshua Prince, Zoe Linda Mary and Oliver Wainaina.

He was a cherished uncle to Nicole, Linda, Favour, Kate, Praise, Darian, Theo, Zahir and Adam. Silas was a beloved cousin to Phui, Douglas, Monica, Joseph, Isaac and Esther.

He was also a brother-in-law to Esther, Ann, and Azrah.

He went to Makerere between 2004 and 2007 after which he joined Kencall outsourcing in Sept 2007 where he worked as a Call centre sales trainer until Jan 2011. He later moved on to Hotpoint Appliances as the Human Resource officer from Jan 2011 to June 2012. He then joined IBM in June 2012 where he held various role amount them Africa Offboarding process owner, Human resource leader East Africa, HR business partner for SouthAfrica and his last role was HR leader for Middle East and Africa TSS/Human resource Business partner Southern Africa.

As a colleague and Employee, Silas was proactive, dedicated and always brought good energy into the room. He was a mentor to many of the colleagues and a great friend to many at the work place. He was unique in his ability to create lasting relationships and created lasting impact to all that interacted with him.

Silas was is in great shape health wise, he was big on exercise, went to the gym and ate a healthy diet. He even tool part in a couple of runs/marathon. On 1st of Sept he was complaining of chest pains and went to see the doctor and it was discovered that he had an Aneurysm(bulge in the wall of an artery) that had burst and caused internal bleeding. As they prepared to take him to surgery he breathed his last at on 1st Sept 2024 at 10.30 pm SA time.