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
