Bijar rugs are notoriously dense. The tight knotting of a rug like this or Nain would probably disperse within the rug as opposed to leak through. Also - yes, you should have some padding, although stay away from pads that have 1. adhesive and 2. are too thick. Many people don't realize how damaging it can be to have too much cushioning under a fine Oriental rug. If someone walks on it with high heals or a heavy table with pointy legs are placed atop a too heavily padded rug it can stretch the foundation.