Weepholes are holes that provide a means of venting water to the outside of a wall. They are used in masonry as a way to ensure that there is no built up possible within the interior of the walls. This also allows for air to pass into the interior of the walls to keep the inside of the masonry dry. The process is done by allowing cracks within the cement to remain unfilled. There are different techniques for this process including putting tubes in the cement that are covered by the cement with netting or mesh over the ends of the tubes.
If you believe that you have trouble with mold, mildew or a general dampness in the walls you will want to contact a home inspector to look over the situation. They can determine if there are any weepholes in the foundation and if you should need them. The professional will assess the entire foundation of the basement walls and determine if there is a general need for weepholes due to changes in grade in the area and potential for water or dampness. This can be very beneficial if you are purchasing a home as well. It will help you to determine if there is going to be a problem with dampness in the basement of the home you are considering.