I put the metal strips used for roof ties on a house in two places to help bridge the two together, unfortunately the pieces do not intersect on a load bearing wall so there is some slump. I mainly wanted to use the eternabond tape as a filler between the two pieces (I have read that it sticks good to wood) but I am not sure how it will react to the adhesive on top of it for the rubber. I will also do a trim strip from below with short staples but there isn't much to grab on with the ceiling and I don't want to screw into the luan from below.