Method of using a toilet-flange cast-in mount

A method of installing a toilet flange in a building, said method comprising the steps of:

• casting a one-piece, tubularly-shaped mount having a bottom end portion with an inside diameter of the size and shape of a female coupling for three inch pipe and a top end portion with an inside diameter of four inch pipe, said bottom end portion defining approximately a three and one half inch internal diameter bottom opening for receiving a three inch pipe and said top end portion defining approximately a four inch internal diameter top opening for receiving a four inch external diameter tubularly-shaped stub of a toilet-flange therein, said top end portion being substantially longer than said bottom end portion and being of such a length as to make the overall length of said mount greater than the thickness of a concrete floor in which said mount is to be embedded;
• attaching said mount to a form for casting said concrete floor with said bottom end portion being adjacent said form;
• casting a concrete floor in said form about said mount with the bottom opening exposed on the bottom of the floor and with the top opening exposed on the top of the floor;
• cutting off said top end portion a sufficient amount so that said mount has a length corresponding to a thickness of the cast concrete floor;
• inserting a three inch pipe into a bottom opening and affixing it to the bottom-end portion and inserting a tubularly shaped stub of a toilet-flange into the top opening, said tubularly-shaped stub having approximately a four inch external diameter of substantial length matching the internal diameter of said top end portion;
• and
• wrapping an intumescent-material collar for closing off three inch pipe in a three inch female coupler about the bottom end portion at a bottom end thereof and casting it into said concrete floor with said mount for expanding and thereby closing off said bottom end portion and the three inch pipe mounted therein when it is exposed to the heat of a fire.