Water intrusion from the roof vent.

I noticed today there was some bubbling of the material lining the inside of the trailer in the sleeping area, and also inside the galley hatch above the light. It appears that it was caused by water entering through the vent housing and the top of the galley hatch. I am going to purchase some Dicore self-leveling seal and reseal the vent. What should I use to seal the top of the galley hatch? Also, is there anything I need to do about the water damage, is there wood that might develop rot if I don't take some preventative action?