The claim that I made was the flashing on the deck was improperly…

I am the second owner of this house. I have no one to sue. The previous owner was my mother and she had the house custom built in 2001. Four years after she had been living in the home (2005) there was a hail storm. She made a claim to her insurance company to have her eaves troughs, downspouts, and flashing replaced. Her insurance company hired a company to do the repair. When they started to remove the fascia, cladding, flashing etc. They discovered that the fascia had not been put on correctly and that the posts and deck floor were rotting. The deck was repaired by the builder as it was still under National home warranty. Then the eaves troughs, flashing, fascia and post cladding was replaced by the company that was hired by her insurance company. However, they too improperly installed the flashing. I bought the house knowing that the deck had been repaired using good materials and proper workmanship (we thought) and there was nothing visible to state the otherwise. We purchased the house in August of 2007 (for fair market value)and by the summer of 2008 we could see what appeared to be, sinking posts. The banister on the deck were bowwing. It took until this June for a contractor to look at and here we are again, a rotted deck because of the improper installation of the flashing. The company that replaced the flashing in 2005 is no longer in business. Not that this would help me but this is why I am very frustrated. This history is probably irrelevant but this how I know that the deck was four years old and should not have fallen apart again.   

What about the clause in my policy that states that damage caused by wet rot is not covered. Even though the improper installation of the flashing, which is not covered, but the damage or loss unless otherwise is excluded (referring to the wet rot.)The insurance company feels quite confident that I do not have a valid claim. The wording in the policy is vague although they do not agree and we are arguing over semantics. The word "Wet Rot" means to them that there is no valid claim. I know what I believe to be right but how does that work with contracts in policies?

They will probably send a lawyer from Dominion. I am feeling intimated by what he/she might argue. What's the argument that he/she might make that could possibly be unexpected and shut me down?

Thanks for the information I feel more confident in pursuing this further.