Modern enterprise web applications need to have reliable functionality. Fault tolerance is one of the reliability factors which can be achieved using modern structuring techniques blended with design patterns. In this paper we improve our architectural pattern XWADF to incorporate fault tolerant strategies in terms of design patterns to make web applications fault tolerant besides achieving scalability and high availability. We proposed two Fault Tolerant (FT) design patterns and incorporated into XWADF so as to make design level decisions that help in developing fault tolerant web applications. We implemented two FT design patterns namely Fault Tolerant Exception Handling Pattern (FTEHP) and Fault Tolerant Security Pattern (FTSP) using Aspect Oriented Programming (AOP) which separates cross cutting concerns from pure business logic thus getting rid of code pollution. The first Design Pattern takes care of faults pertaining to common runtime errors while the second Design Patterns takes care of security related faults. The FTSP is implemented on top of Secure Socket Layer (SSL). We applied the enhanced XWADF to two existing web applications namely Hospital Management System (HMS) and Library Management System (LMS). The empirical results revealed that our Developing Fault Tolerance of Web Applications through Architectural Patterns make applications fault tolerant besides making them scalable with high availability