Of course, every bath is subjected to different conditions so there is no definite answer, however, there are things that you can do to ensure the longevity of your bath. The most import stage of any resurfacing job is the preparation. Make sure that the bath is well cleaned and totally void of any contamination on the surface. When it comes to keying the surface, make sure you pay particular attention to areas where the coating comes to an end such as around the outlet overflow, along the tile line and around the base of the taps.
Aftercare is also very important to the longevity of a resurfaced bath. Do not use cleaners that have bleaches, abrasives or lime scale removers in them. Rather, stick to alkaline soap cleaners. If you do chip the coating by dropping a heavy object into the bath, we would advise you to immediately repair the damage. This will stop water getting between the coating and the bath surface, which will result in the surface peeling off and greatly reduce the coatings useful life.
If you do the above we would expect the new coating to last in the region of 8 to 10 years, but this will depend on the preparation, aftercare and the amount the bath is used.
We have been in the business for over 27 years and our experience has shown that a well looked after bath can last for many years.