
1st things First WELCOME TO THE SITE!!!!!!!!!
Lotsa smart folks who are in the know on our stuff... Some by expierence some by proffession... either way I don't think youll be disapointed...
Most Ducted units are comprised of a standard Aluminum channel/// typicly 8-10" X 2 or 3" if you are getting Black foam rubber, most likley it is from the base of your ac unit. There is a large square foam rubber gasket that the A/C rides on, there may be some "dry rot" or small critter infestation causing this to deteriorate. A Gasket kit is not expensive <20.00, and the AC unit is not to difficult to remove. to remove: remove the 4or 6 screws that hold the facia plate, there will be 4 7/16th bolts that hold the unit down, remove these, unplug the 1 or 2 or 3 connectors that seperate the uper/lower unit... you will then be able to lift the A/C unit off the roof, I would suspect at that time you will see where the problem lies... I hope this helps.. and let us know the out come...