porch roof leaking under deck

Home has a 14' x 20' deck. It is built over a small (9' x 9') three season porch. PROBLEM IS the roof of the porch area is leaking. Water appears to be coming through from deck.
Not sure what the construction of the porch roof is or how the deck is attached to the roof -- but it seems roof may be flat with no real pitch or drainage.
(there is also moss growing on the ends of some of the deck boards which again makes me wonder about standing water on the roof of the porch)

Do I have to remove the entire deck surface to redo the roof of the porch?
If the roof has to be pitched how can it be done without raising it so high you have to step up from the second floor walkout door to the deck.

thanks in advance for any suggestions -

 

in this case the old saying..."a picture is worth a thousand words"....moss generally grows in the less sunny areas...decks are usually boards laid flat with space between each. roofs that are flat have scuppers or are open on the ends...9' x 9' is generally not a big roof and i would suggest a rubber membrane to fix it. being under a deck, i would also suggest a membrane of .060 as well. from what i have read, and not seeing it, i would say that at least the area of deck covering the roof must be exposed to correct this. good luck and hoped this helped.

 

appreciate the suggestions. My current guess is that they might have had some type of membrane on the roof and punctured it (possibly more than once) when they added the deck as I can't see any sleepers separating the two.

looking for the bright side - Guess since we will have to pull up a portion of the deck we can replace a few of the more worn boards at the same time ; - )