Hello, I am in the process of building a hearth for a Drowlet Austral iii wood stove. I just completed my hearth and I’m about to start on my heat shield. I will be using cement board and stacked slate tiles, (I’ve attached a picture at the bottom). I read that I should use a hat channel to give it the 1 inch air gap. I also read that I need to leave a gap at both the top and the bottom to allow for airflow. Does this sound correct? I’ve been looking online and it doesn’t seem like most wood stoves have this gap. Any information is appreciated, I’m a complete novice.