The article deals with construction technique and materials, especially mudbricks and their composition, vis-a-vis specific situation in Tell el-Retaba. Bridging over a thousand years, the construction recommendations of Vitruvius are compared with the current situation in Tell. This article briefly describes three defence walls so far unearthed in Tell el-Retaba and focuses on the research of local ancient mudbricks. It presents results from the examinations of several samples of mudbrick and soil done during recent archaeological seasons. The samples were examined mainly by sieve analysis, testing density, dimensions, walling technique, etc., what also indirectly helps to determine approximate strength of mud bricks and their usage in single structures. The main result, grain-size curves, describing mudbrick composition and their relationship and potential reusing in constructions, are presented. Basic dimensions of the fortress’s gate – Migdol, and defence walls, based on preliminary static calculations of the bearing capacity of the subsoil are also estimated from the point of view of construction engineering.