Vinyl deck leaking

My builder used a vinyl deck covering on a southern exposed 2nd floor balcony. The problem is the deck leaked badly into the room below. It appears the leak occured in one of the corners of the balcony and poured from this point into the room below. He has repaired this 2 times before and is now attempting a 3rd time.

I have also noticed that along the wall were the vinyl siding meets vinyl deck sheeting there is tar coming & leaking out from were the 2 products meet. Several questions come to mind that I hope you can help me to resolve.

1. Is the vinyl deck sheeting the right product for my balcony? It is summer and the temperatures are extremely hot. Someone mentioned perhaps fiberglass is a better option.

2. Is this builder applying the vinyl deck sheeting properly for it not to leak from the corners?

3. If the vinyl product used is okay for this application what is the proper way to fix this (detail needed) so I can make sure he is going to fix this issue the correct way?

4. Why is this tar coming out:

Please know I reside in central New Jersey near the coast. This information could be helpful in your advise.

I really appreciate your help in this situation. The builder is not very helpful in this matter and Im not sure if we can trust what he is telling us.