Plaster for exterior walls of a chimney should be applied direct or on metal lath.  No wood furring or lath.

The hearth, which may be of brick, stone, tile, or concrete, must be supported by a masonry trimmer arch or similar fire-resisting construction.  Both hearth and arch should be at least twenty inches wide and not less than two feet longer than the width of the fireplace opening.

If the mantel is of wood, it must not be placed within eight inches of the jambs, or twelve of the lintel.

The minimum height of chimneys above the roof line is two feet for hip, gable, or mansard roofs, and three for flat ones.

Chimney caps must not reduce the effective draft area of flues.

In connecting the smoke pipe of a heating plant, incinerator, or water heater to its flue in the chimney, the opening must be built with a fire clay tile collar and the smoke pipe should not protrude into the flue beyond the collar.  Otherwise, the efficiency of the draft is materially impaired.

In addition, home owners may have other features installed that will do much to increase heat production of fireplaces and convenience in the use of them.  One is the steel fireplace form, built into the chimney.  This takes the place of jambs, back, throat, smoke shelf, and smoke chamber and is so designed that behind sides and back there is an air space opening into the room through intake and outlet vents on either side of the fireplace.  The cold air of the room is drawn into this space, heated by radiation and returned.  It acts on the order of a hot air furnace and can be used to advantage in new fireplaces or in old ones too much out of repair to be used without rebuilding.

There is also the sheet-steel smoke chamber which comes complete with throat damper and smoke shelf and is put in place above the lintel where it extends to the point where the flue commences.  A common device for easy disposal of the ashes is the ash dump, a small cast-iron vault located in the fireplace floor and connected with an ash vault built in the chimney foundation.  The vault is equipped with an iron door so that the ashes may be removed once or twice a year.

So much for chimneys and fireplaces.  For actual and even heating of all parts of the house, some type of heating plant is necessary both for comfort and economy.  It is true that our forefathers lived, many of them to a ripe old age, with only fireplaces to heat their drafty homes and with no heat at all in their public buildings.  They did, however, fortify themselves well with a daily draft of rum and they wore a quantity of clothing that would be intolerable today.  Further, plenty of wood for fuel grew at their very door; it was part of the normal farm work to cut it down and prepare it for the cavernous fireplaces.

But then, as now, a fireplace could only heat a comparatively small area.  Further, under modern conditions, it is the most expensive heat that can be generated.  Even though your holding includes a good sized wood-lot, the cost of labor for getting fuel cut, drawn, and piled in your cellar may run to more than the same amount purchased from the local coal yard.