Thank you nYour assistance has helped me resolve this problem, and i have a nice clean geometry to import into mechanical. This has eliminated a host of problems that i was having in mechanical such as elements loosing properties, issues with nodes in surfaces etc etc.nnI have had to reduce the coincidence tolerance to 0.08m, but i consider that this is necessary as the gap between adjacent surfaces is 0.1m. A screen shot of this solution is provided below to close out this thread.nnMany Thanks.nnPS. The slab is formed with a rectangle in sketch and its edges are used for the beams.n