Next week I am going to take care of several handyman projects for a lady trying to get her deceased mother's house ready to sell. One of the jobs involves so-called water stains on a basement wall and they want it painted. I have not seen the wall yet and I don't have a picture. They did not know if the seepage had been taken care of or not. Should I just seal and paint it per their request? Is there a good way to insure some measure of waterproofing at a reasonable cost for them. Thanks for any ideas.