Sometime in the past a contractor installed this flashing between the siding and the concrete stoop. He sealed it with tar and then concreted over, which, of course, failed and has been leaking water under the flashing. The stoop gets a lot of water coming off a valley just above the brick column where I am going to install either diverters or capless gutters and is exposed to the elements, getting rain and south Mississippi morning sun. I’ve removed the concrete he used to cover the flashing and fixed all the water damage from the inside. The flashing goes between the subwall (tongue & groove heart pine) and the outside siding so the outside siding wasn't damaged, just the subwall.
Any ideas on the best way to seal the flashing to the concrete, especially considering it is exposed? No problems in caulking the top part of the flashing where it meets the siding, but not sure what to use to seal the flashing to the concrete. I’ve thought about using some type of urethane adhesive and then covering with something like a strip of EPDM single adhesive roofing repair/joint tape (but I don't know whether that would bond to concrete or how it would look). I don’t think flashing tape is a good choice because of the exposure. Whatever I come up with, what would be the best way to prepare the concrete for a good bond?
I have been hesitant in removing any of the siding because if I damage it I will have to have it remilled since it is not a standard profile. I am willing to remove it someone knows of a better way to flash this.
I know this is a bad design and the best solution would be to tear out the stoop but that is not an option at this time.