Joists in basement
Anybody can advise what the black/brown (whatever colours) strip is at the bottom of the joist in my basement is?
16'x11' Living Room 11' Cathedral Ceiling. Hisense 65Q8G. Denon AVR-S740H 7.2 setup. Jamo Classic 10 280W Towers - FR+FL; Polk S35 - Center; Klipsch R51M - RR+RL; Klipsch R14M - Dolby FHR+FHL; Polk HTS10 Subwoofer x2. Unlocked Android Boxes from Taiwan x2