In recent years, the construction industry has experienced a significant shift toward relying on numerical analysis over traditional experimental methods. However, the demand for in-situ tests like the Flat Dilatometer Test (DMT) is growing rapidly due to the accuracy and efficiency of geotechnical parameters obtained from these tests. The DMT has become an emerging area of research, particularly in experimental geotechnical engineering. A thorough literature review reveals that the thickness of the DMT membrane is chosen based on subsoil properties. Typically, a 0.25 mm thick membrane is used for firm/stiff clay and sandy soils, while a 0.30 mm thick membrane is preferred for dense, angular sandy soils. As membrane thickness increases, the pressure range (∆A and ∆B) needed to overcome membrane resistance also rises. Specifically, the pressure range for a 0.25 mm membrane is 15–20% higher than that for a 0.20 mm membrane. The authors encountered a problem at a project site in Kolkata, where the sandy subsoil damaged a 0.25 mm membrane at depths beyond 2.0 m. Switching to a 0.3 mm membrane allowed deeper penetration without damage, though the ∆A and ∆B pressure readings increased compared to the 0.25 mm membrane. It is observed that the pressure readings of ∆A and ∆B required to overcome the membrane thickness of a 0.30 mm thick DMT membrane are 38–66% more than a 0.25 mm thick membrane.