Good Evening, I have a wood burning insert that is completely supported inside a masonry chimney. My old brick hearth was crumbling due to insufficient support underneath all the weight. Tore it out. Now what I'm left with is a brick wall with an insert installed in it's opening approximately 10" above the plywood floor. I've built a 2x8 frame 80" wide and 24'' deep for a new hearth. I plan to cover the frame with 1/2" durock on front and sides and 2 layers of 1/2" on top and finished with tile. Obviously, the stove will not be sitting on the frame that I'm building. After searching the site, I find that there are many differing opinions on what is acceptable in the situation I have. Is my setup safe?