The cure progression of one-part room temperature vulcanizing (1-RTV) sealants and adhesives is a vital intrinsic material property for their typical end-use applications. Understanding the key factors controlling the cure mechanism becomes more and more important given an ever-increasing demand to improve productivity by allowing assemblies using these materials to move faster through the manufacturing process. For 1-RTV systems, ultimate mechanical and adhesive strengths attain an equilibrium value as their cure proceeds in the presence of atmospheric moisture. A diffusion-controlled, moisture-cure mechanism was established for this family of materials about 10 years ago, most definitively by Comyn et al. The depth z of unidirectional cure with time t was derived to be a function of the vapor pressure p of water in the atmosphere in the proximity of the material surface, and two material properties: the permeability P of moisture through the cured layer and the equivalent material volume V reacting with 1mol of water, and cure time, t, i.e. z=(2VPp t)(1/2). Hence, the thickness of the cured layer should increase as t(1/2). That is, a plot of z vs. t(1/2) should yield a straight line where, for a particular RTV material, the magnitude of its slope is a function of the temperature and relative humidity (RH) during cure. This was shown for organic hot-melt adhesives and silicone sealants; validation of the moisture-cure model was demonstrated using gravimetrically based measurements to determine V and P separately. However, a deviation from the moisture-cure model was reported from a study using an alkoxy silicone sealant in geometries requiring deep-section cure and, therefore, longer cure times. An increase in the slope of the z vs. t(1/2) plot was observed after a certain timexinterval that was a function of cure conditions. The change in cure rate was attributed to the migration of low molar mass crosslinkers and adhesion promoters towards the cure front and the eventual depletion of these species, which compete with the silicone polymer for reacting with the diffusing water. It was possible to determine the diffusion coefficient, D, of additives that act as adhesion promoters and crosslinkers in uncured alkoxy silicone sealant. From these studies, the utility of the moisture-cure diffusion model was demonstrated. The variables impacting cure performance are reviewed; and, a generalized form of the model is presented to account for variability in cure rates observed over extended time intervals in assembly geometries requiring deep-section cure. By plotting z as a function of (tp)(1/2), data-sets for each material collected at different conditions of temperature and RH merged into a single straight line with a very high coefficient of determination. For end-users of 1-RTV silicone sealants and adhesives, this latter approach provides a material-specific reference line that demonstrates the correspondence between cure time and vapor pressure; i.e. a certain cured depth can be reached at short cure times with a high RH or at long times with a low RH.