Answer: no, the support of a parquet must be stable, clean and dry.
You cannot directly lay new parquet on an old degraded parquet. The laying of parquet requires a stable, flat, clean and dry support. If these conditions are not met, your new parquet will deteriorate very quickly in turn. There are two options available to you in this scenario: either you remove the old parquet, or you renovate it entirely before installing the new one. If the old parquet is really in very bad condition, you might as well get rid of it, and put the new one on a healthy support. You will not necessarily save money by keeping it, on the contrary. Because you will have to clean and sand the old parquet (so rent or buy a sander), maybe even make a leveling of parquet before you can install the new one. You too, send us your brico question