This area is often a home for mold, fungus, mildew, and any organisms that thrive in damp and shady places. In the regions of high precipitation, basement flooding becomes a serious issue. Proximity to water bodies also increases the chances of the same.
In such cases, you may need periodic maintenance of exterior drainage components. Although, a waterproofing paint does not prevent the flooding, it certainly protects it from all kinds of infestations. Moreover, it also renders an aesthetic appeal to the same.
You should take the pictures of your basement along with you, so as to enable him to study its condition. The product should have an anti-mold formula to inhibit the growth of mold and mildew. Oil-based paints with resins are good for these walls due to their moisture-repellent properties.
An interior oil-based or latex paint is the best option. Since, they are available in an array of colors, you should not have any problem matching it to the rest of the décor of your home.
If you find any, get it fixed from a professional plumber only. You don't want the task to get ruined by seepage of water. Scrape off any old paint and get rid of any stains or marks on the walls. Apply a bleach solution or any basement mold removal product to get rid of mold and mildew.
If it is damp, the paint will not retain properly. Hence, allow proper ventilation inside the area. You may need more than one device, if you have a considerably large area. These can be obtained from equipment rental shops. Continue the rest of the task in the usual painting method. Use rollers for wider areas while brushes to reach the narrow areas.
Compromising on quality of paint may result in ruining of the walls. Moreover, the growth of mold and mildew may invite a plethora of health troubles.