An electrochemical method for the synthesis of branched Si backbone polymers is described. The method offers an attractive alternative for the synthesis of branched silane polymers having general formula Si(RHx)(n) which are of interest as soluble polymer precursors for the formation of SiC. Under these mild reaction conditions, the polymerization of alkyltrichlorosilane monomers is slowed considerably compared to thermal reduction methods, allowing a manifestation of differences in reactivity of monomers in the series: methyltrichlorosilane, n-butyl-trichlorosilane, and cyclohexyltrichlorosilane. The different product distributions obtained are attributed to the influence of steric effects upon intramolecular cross-linking and intermolecular chain propagation reactions.