Efflorescence on brick is a condition that develops when moisture from within the brick rises to the surface and evaporates. The residue is a deposit of mineral salts that looks like a white powdery substance. Since the cause of the efflorescence is excessive moisture behind the brick, first find its source and correct the problem. It might be a leaky gutter or loose downspout that allows rain to run down the brick. Or it may be as simple as adding caulk around doors and windows to prevent moisture.
When the cause of the efflorescence is solved, you can remove the white powdery surface by cleaning it. A house cleaning service will charge $203 to remove efflorescence from a150-square-foot area of brick. You can remove the substance for $25, the cost of a clear water sealer, and save 88 percent. You need a stiff bristle wire brush and a garden hose or a power washer to scrub the surface. When the surface is clean and dry, then apply a clear water sealer to protect the bricks.
