Q. Two- or three-quarter-inch-thick fire bricks have fallen from the lower center-back portion of my fireplace. Othe bricks behind them, however, are stable. What shall I do? Donald M. Rauch Palo Alto, Calif.
A. Quarter-inch brick veneer in a fireplace combustion chamber is most unusual, even to the Brick Institute and the Masonry Institute of America, a trade organization.
Falling brick may be a spalling problem. When brick spalls, the face of a unit becomes detached from the body. A closer inspection is required to determine if this is the case in your fireplace.
If it were my fireplace, I'd call a veteran brick mason for his inspection and a report on the cause and cure.
You might like to read a booklet put out by the Department of Energy entitled "Heating With Wood." Another booklet, No. 152H, is entitled "Fireplaces and Chimneys." It costs $1 and can be ordered from the Consumer Information Center, Pueblo, Colo. 81009.