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.
There is no single agreed upon length for pieces of wood in a face cord. On average, the length of most firewood is 16 inches (40.6 cm), so the depth of most face piles is 16 inches (40.6 cm). This is one-third the depth of a full cord.