Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
E04F17/00—Vertical ducts; Channels, e.g. for drainage
E04F17/02—Vertical ducts; Channels, e.g. for drainage for carrying away waste gases, e.g. flue gases; Building elements specially designed therefor, e.g. shaped bricks or sets thereof
E04F17/023—Vertical ducts; Channels, e.g. for drainage for carrying away waste gases, e.g. flue gases; Building elements specially designed therefor, e.g. shaped bricks or sets thereof made of masonry, concrete or other stone-like material; Insulating measures and joints therefor