The vacuum tube in a CRT can implode if it is broken or punctured. The surrounding air will rush violently into the unsealed vacuum in the CRT, spraying broken glass in every direction. Color CRTs may contain mercury or other potentially toxic materials.
Instructions. Build a hearth for a fireplace that is 16 inches deep, according to This Old House writer Harry Sawyers. This is the standard requirement for municipalities and homeowner associations. The hearth should also extend a minimum of eight inches on either side of the fireplace.
The limiting factor is the depth. I have 1,800 SF with a full basement so about 3,600 total. The fireplace is about center of house on the main floor and is in the room we will spend most of our time. Long burn times are desirable but 12 hour sounds great. I am open to the fireplace selection at this point.