The report describes the modelling procedure for MCNP of the ASPIS Iron88 shielding benchmark experiment form the SINBAD database. In the first part of the report motivation behind the modelling is given. The report continues with a detailed description of the geometrical properties of the benchmark with the Rhinoceros CAD program and the transformation procedure of the CAD model in to MCNP format. In the next part of the report details are given on the material, source and detector (tally) modelling of the benchmark experiment. Furthermore the variance reduction procedure using ADVANTG is described. Finally the results of the comparison of the experimental results to the calculation results for five different detectors (Sulphur, Indium, Rhodium, Gold, Aluminium) and with four different nuclear data libraries (ENDF/B-VII.1, ENDF/B-VIII, JEFF-3.3 and JENDL-4.0u) is given. Results for the Gold activation foils are only preliminary at this point and require an additional sensitivity study before they can be recommended for nuclear data validation applications.