Several recent papers have investigated the effect of ignoring bulk recombination in derivations of the sink strengths required for the rate theory of void swelling, irradiation creep, and growth. Although most of this work has concluded that bulk recombination can safely be neglected in such procedures, some uncertainty remains. Numerical calculations to eliminate this uncertainty have been made that compare explicit spatial grid and continuum representations of a thin foil, and are performed for irradiation growth in zirconium. It is found that the growth strain predicted using the continuum foil sink strength, derived without bulk recombination, is always within ∼20% of the spatial result and is usually in much closer agreement.