If you have experienced water damage in your home or office which requires removal of the padding, you may be ok just to have the padding replaced as needed and save and reinstall the Carpet. Here are. a few of the things to observe. 1. How old is the Carpet. 2.Has the Carpet ever been wet in the past. (other than cleaning). 3.How long did the Carpet stay wet before drying out. If all these questions are minimal answers, your carpet should be fine to only replace the padding. You would always want to replace padding due to the fact that when Carpet gets wet, the padding is what soaks up the majority of water and has the highest mold risk. There is no surface area for the air to move the moisture such as Carpet. Also your backing on you Carpet should be in tack if is the first or possibly second time it has gotten wet. So yes, absolutely more times than not, you only need to replace the padding and not the Carpet. Save your money there and your Carpets will be exactly how they were prior to and water damage.