Is it permissible to apply mastic OVER old joint tape?
I have a home with late 1940’s construction. The ducts in the basement ceiling are all sealed with a white tape that is becoming frayed and in poor condition. I’m sure the lack of proper sealing has compromised the system.
I have had varying opinions on whether or not the tape may contain asbestos. I have not had it tested because I’m not sure how I’d go about that.
I’m wondering if I could just coat the tape with mastic, serving both to seal the leaky seams and encapsulating the existing tape if it does contain asbestos.