The growth of Si(001) from a gas source molecular‐beam epitaxy system (Si‐GSMBE) using disilane (Si2H6) was investigated. The surface reconstructions occurring between 100–775 °C were studied as a function of both substrate temperature and surface coverage. Further, we report the first observation of (2×2) andc(4×4) reconstructions during growth at substrate temperatures near 645 °C using Si2H6. All growth was found to be initiated by the formation of 3D islands which coalesce at substrate temperatures above 600 °C, following which, growth proceeds in a two‐dimensional (2D) fashion. The Si surface was found to have undergone a series of reconstructions which were related to the number of hydrogen adatoms and Si dimers covering the surface.