We had to decide between regular carpet pad and the "pet proof" waterproof pad that has a moisture barrier on top. I was going to go with the waterproof pad - seems to make sense, especially with pets and kids. However, you should do a quick search on the internet first. I did and saw enough comments that explained that IF moisture should get under the waterproof layer - either through cuts, etc., the moisture would then be trapped UNDER the waterproof layer and would have no way to escape. That info impressed me enough that we ordered the regular pad with no moisture barrier. I steam clean my carpets sometimes. Carpet salesman was taken aback that I didn't want the moisture barrier - everyone gets it and I really did want it, but was too afraid if water should get under it.