The rock-cut tomb–chapel of Djehuty (Luxor, Egypt, 1470 BC) was excavated and restored including a mineralogical, chemical, textural and petrophysical study of mortars and host rocks together with micro-environmental parameter recordings to deduce the techniques used by the ancient Egyptian builders. The host rock is made by alternations of massive, nodular and finely bedded micritic limestone and the tomb was excavated in the stratigraphic section with better mechanical properties. Different types of gypsum and lime mortars were found in the funerary complex: mortar for bedding, exterior render, surface repair and decoration, and interior plaster and coating. Mortars show formulae according to their specific applications and locations. The sources of the raw materials for the mortar reveal a local provenance. Micro-environmental conditions play an important role in the evolution of the mortar pastes, and determine the current characteristics and stability of mortars. Results from this research will make it possible to design mortars compatible with conservation in the funerary complex of Djehuty and to define safe micro-environmental conditions for the preservation of such mortars and paintings.