How To Build a Fireplace

The arrangement of two fireplaces on different levels, including the use of a cleanout door adjoining the basement fireplace, has be­come quite popular with the trend toward basement recreation rooms.

Often, the chimney used for the living room fireplace is also used for the one in the basement, but here, many mistakes are made as to ventilation of both fireplaces through the same flue, or the un­necessary elimination of an ash­pit for the living room fireplace.

Each fireplace should have a separate flue. If it becomes neces­sary to slope the flue, it should not exceed the rate of seven inches of slope per foot of rise and should take off from the center of the smoke chamber, with the entire slope taking place above the chamber.

The ashpit for the "upstairs" fireplace can be located right next to the basement fireplace, which if properly constructed, will give the basement fireplace the ap­pearance of having an adjacent oven. And if proper care is taken when removing the ashes, having the ashpit in the basement recre­ation room presents no problem.

Next, the lower, or cold air grilles, should be set in place. The masonry may then proceed upward in the regular way. always keeping a ½ insulation between the Circulator and the masonry. The masonry must support all weight of the chimney. The Circulator is not to be used as a support for the masonry.

When the brick work reaches the top of the fireplace opening, sot the angle iron lintel to support the brick work above the opening. The lintel should be at least 3½" by 3½" by ¼. being sure that it clears the Circulator by ½". Pad the lin­tel at the ends and back with plenty of insulation.

Set the upper 1 warm air) grilles in the same manner as was done with the cold air grilles. Finish the inside of the duct connecting the Circulator casing with the grille frame smoothly, but do not run the finishing coat of mortar against the Cir­culator casing itself.

The height of the brickwork compris­ing the face of the mantel must be at least one inch above the top of the housed por­tion of the Circulator. When this point is reached, cover the entire top of the Cir­culator with insulation. Then set 5" by 5" by ?"angle iron across the brick work to support the masonry above, and pro­ceed to make a tight connection to the flue.

In building a low-type mantel, when the face of the Circulator has been built up to the desired mantel height, drop back to where the dome angles away from the face of the fireplace and cover the dome with insulation material. Then apply ma­sonry in the space between the fireplace face and insulation until it is flush with the top of the face. Be sure to make a tight joint with the flue.

Do not build a hot fire in the fireplace until the mortar dries thoroughly, which will probably take two or three weeks

When installing a Majestic Circulator Fireplace, the mason should carefully read all the directions to be sure he understands how the work should be done. Complete instructions are included with each indi­vidual Circulator.

First, he should inspect the Circulator

to make sure the insulation and all acces­sories are readily at hand. Then he should check the dimensions of the footing, being sure that the firebrick hearth is perfectly level, with the ash dump approximately in the center of the firebox after the unit is set. The hearth should extend beyond the sides and back of the unit, and at least flush with the front.

After the Circulator has been set, and before any brick work is started, the in­sulation should be unpacked and applied around the bottom of the Circulator. Use double insulation at the corners and be sure the entire unit is covered. A thin mortar applied to the Circulator will hold the insulation in place.

Plumb the brick work against the ad­justable angles at either side of the open­ing so the angles will always cover the space between the brick work and the unit.

By setting a few bricks, the mason can gauge the size of the mortar joint and see that the corner breaks at the end of the brick. If a fan is used, the conduit for a power line should be built into the ma­sonry. Bring the outlet boxes as near to the grille boxes as possible for easy con­nection by the electrician. Always use two fans, one in each cold air box.

If the fireplace is on an outside wall and the provision for an outside air inlet is desired, it will be necessary to cut an opening approximately 16 inches wide and eight inches high in the back of the casing; then connect with the adjustable ventilator grate.

One of the questions most often asked b nearly everyone who plans to build home is:  "Should I have a fireplace¹? Well, there’s no cut-and-dried answer Different people place different value on fireplace utility and appeal. However one intangible quality that weighs heavily in its favor is the friendliness of fireplace.

STARTING  THE  BLAZE

Before lighting the kindling, lay about a half-sheet of newspaper on top of the logs and set fire to it. This warms up the flue and establishes a draft. While this piece is still burning, light the loose ends of the kindling paper. Close the screen and your fire is started.

A  FIRE  NEEDS  AIR

Burning fuel in a fireplace requires a good deal of air. Tight weatherstripping with storm sash may not permit enough air to enter the house to sustain the fire properly, open a window a little way . . sometimes leaving the door to the base­ment open will do the job.

Watch out for the effect of ventilating fans. Even a small kitchen fan exhausts a good deal of air from the house. If there is no way to replace this air. except down the chimney, your fireplace will smoke and. in extreme cases, ashes may be drawn out (into the hearth extension even through the closed screen.

TO  BED  FOR  THE NIGHT

If your fire hasn’t burned itself out by bedtime, use the tongs to stand any un burned logs up on end in the corners of the fireplace. In this position they will soon burn out and you will have some good kindling ready for the next fire Be sure the screen is closed to keep random sparks and embers off the floor or rugs

SOME DOS  AND  DON TS

Don’t be disappointed or impatient if the fire seems to die out in its early stages. A first-of-the-season fire may need more kindling or perhaps another half-sheet of newspaper burned in the flue.

Most important — let a bed of ashes accumulate under the fuel. Not too thick — about an inch or so deep — hut spread around evenly over the whole hearth area The ashes insulate the cold hearth and your later fires will start much more readily

Don’t try to build too big a fire. Three logs are ideal and four should he all you will ever need for a comfortable, cozy eve­ning. As the top and front logs burn up. turn them around a bit with the tongs and place a fresh log on top.

Keep your fireplace screen closed, espe- cially when leaving the nx»m or whenever sparks might pop out unobserved to smol- der on floor or rug.

Most fireplace owners prefer to burn logs as fuel. The use of coal or char­coal requires the building of a wood fire to ignite it, so most of the points given here will be of value regardless of which fuel you prefer.

WHAT  TO  BURN

Dry and seasoned hardwood makes the best fuel. Logs may be split or whole and should be from 16" to 22" in length. Soft woods burn away too quickly, and wet green wood will give a smoldering, unsat­isfactory fire.

Don’t burn scrap lumber or refuse. This sort of material is generally so dry that it produces a great many sparks which will escape up the flue and he a worry if not a real hazard to your neighbors and to you, if your home has a combustible roof.

TOOLS  AND   EQUIPMENT

You should use either andirons, a bar grate, or a basket grate to hold the logs in the proper position. Andirons are usually chosen for decorative appearance, and some owners prefer a basket grate with andirons set in front of it for decoration.

Whether you burn wood, charcoal, or coal, you will need a pair of tongs, a small shovel, and a poker, since half the fun of owning a fireplace is in "tending" the fire A hearth broom is handy for brushing up stray ashes that spill out on the hearth extension. A wide variety of other gadgets are available, but are more ornamental than useful.

Place your andirons about 12" to 16" apart, equidistant from the centerline of the hearth. Lay a fairly generous amount of crumpled or twisted newspaper on the hearth between the andirons, leaving a few convenient loose ends for igniting. Ar­range a criss-cross of kindling sticks, such as pine, on top of the paper.

Now set the longest and thickest of the logs (4" or 5" diameter) across the and­irons toward the back of the fire chamber —not tight against the back . . leave about a half-inch space. Place a second piece, preferably a split log. a few inches in front, then another split log on top so as to form a sort of crude pyramid.

Any openings in chimneys should consist of a metal thimble around which the brickwork is carefully laid and cemented. Boiler clay or putty should be used to make any loose smokepipe connections air-tight.

WALL  STRUCTURE

The walls of both exterior and in­terior chimneys without linings, and exposed walls of exterior chimneys, must be at least eight inches thick The walls of the interior chimney with flue linings must be at legist four inches thick. Interior chimneys should have eight-inch walls from below the roof to the top. Flue lin­ings should be separated by brick divisions or withes at least four inches in width- The walls of stone chimneys should be at least 12 inches thick.

CHIMNEY  AND  ROOF

Careful consideration should be given to the proper connection be­tween chimney and roof. This is one of the principal points at which a fire can start. Therefore, at least a two-inch clearance should be provided for between the wood framing and the masonry. This will also allow for expansion or movement of the chimney due to temperature changes or strong winds

CAPPING

A chimney cap should always be provided so ;is to reduce chimney maintenance. The top surface of the cap should slope upwards to the flue to provide water drainage, and to deflect air currents upward as they pass the chimney top. When a hood is used, the area of the hood opening should be at least equal to to the area of the flue. Concrete and brick caps are usually made four inches thick, and it is advisable to project them an inch or two to form a drip ledge

A chimney is a necessity with any fuel-burning equipment. It must be capable of producing and maintain­ing a draft to bring a supply of fresh air to the fire. Also, it mast carry away particles and harmful gases emitted from the burning fuel. The chimney, and the flue within the chimney through which these gases travel, must be carefully built to be free of fire hazards. A defective or overheated chimney is the greatest single known cause of residential fires

MATERIALS

The common brick is suitable for chimney construction, but firebrick should be used for the inside course, if a flue lining is not used. Fire­brick resists heat and temperature changes more readily than ordinary brick. Stone can also be used, but the necessary thickness of the wall often is not desirable. Concrete block can also be used, and solid block units can be used to erect chimneys of any size and shape. These units are sized so they combine easily with rectangular and circular linings.

FOUNDATION

A solid concrete foundation, 36" deep and extending 6" wider and longer than the chimney plan, is usu­ally sufficient. Since regional re­quirements differ, consult your local building code. To determine the weight of the chimney, figure brick at 130 pounds per cubic foot and con­crete at 150 pounds per cubic foot. Figure entire cross section cubage.

FLUE

The flue lining must be capable of withstanding rapid changes in tem­perature. The liner used should be made of fire clay not less than five-eighths of an inch thick. Cracks or other imperfections in any part of the section make the whole length unfit for use. Brickwork and mortar joints have a tendency to disinte­grate when exposed to flue gases. This, combined with natural weath­ering, will cause cracks in the masonry, reducing the draft and causing fire hazards. So whenever a flue lining is omitted, an eight-inch thickness of masonry wall should be used.

Flue precautions

The flue lining must withstand rapid changes in temperature. It should resist the acid action of flue deposits and moisture. Flue liners of vitrified fire clay, not less than ?" thick, in either round or rec­tangular shape, afford the best answer.

Moisture

It is advisable to project the flue lining about four inches above the cap on the top course of brick, then surround it with at least two inches of cement mortar, finished with a straight or concave slope. This drains water from the top of the chimney, and directs air cur­rents upward.

ANSWER: A chimney should extend at least three feet above flat roofs and at least two feet above the ridge of a peak or hip roof. Solid masonry is the most commonly used material. Satisfactory performance of a chimney flue is deter­mined by its size, direction, shape, height, tightness and smoothness.

ANSWER: The brick around a fireplace and flue should be laid with cement mortar, since it is more resistant than lime mortar to the action of heat and flue gases. The best to use, except on firebrick, consists of one part portland cement, one part hydrated lime, and six parts clean sand. Firebrick is best laid in fire clay.

ANSWER: A damper affords a means of regulating the draft and prevents excessive loss of heat from the room when the fire is out. It consists of a cast-iron or steel frame with a lid hinged so the width of the throat opening may be varied from a closed to a wide-open position.

4. What is the proper procedure for connecting the chim­ney to the roof

 so as to guard against fire, and to allow for expansion due to  temperature changes, settlement, or slight movement of the chimney

 during heavy winds?

ANSWER: Where the chimney passes through the roof, provide for a two-inch clearance between the wood framing and the masonry. The chimney must be flashed and counterflashed to make its junction with the roof watertight. Cor­rosion-resistant metal, such as copper, galvanized metal, zinc, aluminum, or lead is best for the counterfiashing. When tin is used, paint it well on both sides.

ANSWER: Chimneys can be built without linings, but those with linings are more efficient. When the flue is not lined, the mortar and bricks directly exposed to the action of fuel gases disintegrate. This disintegration and that occuring from changes in temperature often cause cracks in the masonry, which reduces the draft.

ANSWER: The smoke shelf should be made by setting the brickwork back at the top of the throat to the line of the flue wall for the full width of the throat. The depth can vary from six to twelve inches or more, depending on the depth of the fireplace.

7.   Does the kind of fuel to be burned have anything to do with the selection of a fireplace design, and does the size of the opening affect the operation?

ANSWER When a fireplace design is being selected, the kind of fuel to be burned should be considered; also, the design should harmonize with the room in proportion and detail. Years ago. when cordwood was plentiful, fireplaces seven feet wide and five feet high were common, but they required large amounts of fuel and were often smoky. Where cordwood is cut in half, a 30-inch width is desirable for a fireplace, but where coal is burned, the opening can be narrower. Thirty inches is a practical height for the fireplace where the width is less than six feet. The higher the opening, the greater the chance of a smoky fireplace. In general, the wider the opening the greater should be the depth.

and here are the reasons why

FLUE

The flue is a vent that carries the products of combustion out of the house. Its size governs the volume of smoke it can handle; its height determines the produc­tion of draft.

SMOKE CHAMBER

This is the space extending from the top of the throat, or damper, up to the bot­tom of the flue, and between the side walls. Generally triangular in shape, it serves to funnel the smoke into the smaller area of the flue opening.

SMOKE SHELF

A horizontal shelf as wide as the throat and extending back from the top of the throat to the line of the flue wall. It diverts downdrafts and causes them to eddy into the rising air currents.

DAMPER

A metal frame that shapes the throat and is provided with a hinged lid, or valve, to regulate the draft and to close the throat when the fireplace is not in use.

FIREBOX

The chamber which actually contains the fire, constructed of firebrick or metal, with the sides splayed and the back sloped to reflect maximum heat into the room.

HEARTH

This is the bottom of the firebox, or the area on which the fire is built. It should be of firebrick or other fireproof material. Its extension into the room is also called the hearth, and should be a fireproof area not less than the width of the fireplace opening plus 16 inches, projecting at least 16 inches from the chimney breast.

ASH DUMP

A metal frame with a pivoted plate, located flush with the hearth surface and usually centered towards the rear. It is a convenient means by which ashes can be dropped into a pit below.

ASHPIT

An ashpit can be built into the fireplace base below the hearth to serve as a storage place for ashes.

CLEANOUT DOOR

A necessary opening into the ashpit wall to provide a means of cleaning out the accumulation of ashes. The door should be of metal and should close tightly.