A recent study introduced a first-principles based methodology for projecting time-to-corrosion initiation for reinforcing steel in concrete exposed to chlorides. In this paper the methodology is expanded to also include corrosion propagation time to the point of surface concrete cracking/delamination TP. All variables in the previously presented method (effective diffusion coefficient (D) surface chloride concentration (Cs) reinforcement cover (x) and critical chloride concentration (CT)) were treated as distributed rather than distinct as is known to be the case. The present approach is unique in that TP is also treated as distributed. Results from example analyses that incorporate a range of distributions for the above five variables are presented and discussed for both black and corrosion resistant reinforcements.