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.
Such egress must be directly to the outside and must be at least 5.7 square feet (grade floor openings maybe 5.0 square feet) with a minimum height of 24â and minimum width of 20â. Sill height shall be no higher than 44â. 5. Gas water heaters and gas furnaces may not be located in a bedroom or bedroom closet. 6.