Pattern-based web applications have become popular since they promote reusability and consistency. In few cases, patterns do not produce the desired effect because of lack of experience in applying them. This situation forces one to think of a suitable reengineering solution for such applications. The objectives of the paper are three fold. It provides a survey of different pattern-based web applications that will be useful for the application designers. It highlights some of the web applications where patterns have been inappropriately handled. A few re-engineering initiatives for such cases are also analyzed.