Monotonously increasing water concentrations at silica surfaces can be described by a mass transfer surface condition for diffusion that hinders free water penetration from a water vapour environment into silica. So far, the related mass transfer coefficient has been determined predominantly for tests at temperatures $\geq \ $250°C. For an extension of the database, experimental results from literature at temperatures $\leq \ $200°C are studied. These measurements are surface water concentrations and disk curvature
measurements, both under saturation vapour pressure.