What can I do with this leaking chimney? https://imgur.com/a/vPo2zo6
TL;DR: Can I retrofit flashing somehow if there is none?
The roof is bitumen/tar, coated with a silver/metallic reflective layer. The roof overall seems in good shape, it was put on about five years ago, it seems whoever did the roof decided to cover the brick chimney with tar at the same time, the chimney was completely covered in tar/roofing cement, which has dried up and is pulling away from the brick, I started pulling the tar off to see what was behind, and sure enough it was wet and moldy. The uncovered part is what I have exposed so far.
I am not sure whether there is flashing under the tar at the bottom part of the chimney, I hope there is.
My plan is to remove the tar on the top part of the chimney, repoint the brickwork and then seal the brick with a paint-on drylok siloxane masonry sealer.
My concern is what to do around the bottom part/flashing area. How low should I go pulling off the tar? If I find no flashing as I go down, what can I do?
Is it possible to retro-fit flashing over the existing built-up-roof, with additional layers of bitumen and cement on top of the new flashing? Or instead would I need to pull up the roof around the chimney all the way down to the sheathing in order to install flashing?
Thanks very much for any advice.
This is located in New Jersey.