The house is 80 eyars old, and it does require some work.
the ffunnniest thing i found is that the heating vent in the bathroom was built in the longest wall of the shower/bathub, at waist level.
there was water going trhu th heating vent, and started damaging the ceiling in the kithce, which is lcoated below the bathroom.
I took down the cement board shower walls and I have raised the heating vent almsot to the ceiling. I bought DensShield, but I have read bad reviews about it. Now I feel I should use CBU or another cement board. What do you think?
Another question I have is, will the cement board get damage with the bathroom mositure where the heating vent is located...I plan to seal it as tight as i can. But I am afraid this probelm can be only solved by moving the heating duct to antoher wall, which would require a huge bathroom renovation, and the room beside it. I would like to avoid this.
I prefer a cbu. You want to install a vapor barrier behind it, since, while cbu won't be impacted by moisture, it can pass it into the walls, thus the moisture barrier. Essentially near the ceiling should keep the register okay.
There's a company that makes a neat floor register that can be tiled which may be a good solution for you - I think it would also work well in the wall. I thought I had the site bookmarked, but you should be able to find it with a Google search. For some good help on tiling, check out www.johnbridge.com.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013