When you say Drylok primer, do you suggest Drylok Masonry Waterproofer ,which happens to be a paint but isused since the primer for elastomeric paint? It is possible to go In either case. If the existing elestomeric coating is in superior form, just pale, then normal good paint is okay. http://erickkmlih.pages10.com/5-Tips-about-exterior-painters-reviews-You-Can-Use-Today-27305807