Cleaning Brick Fireplaces

Where there’s fire there’s smoke, so a working fireplace naturally accumulates smoke and soot. The stains and residue from smoke and soot can be especially hard to clean. If you are not careful, you might damage or discolor fireplace bricks. The following guidelines can help you clean brick fireplaces safely and effectively.

Smoke
Smoke is a difficult stain to remove. Try scrubbing with scouring powder (preferably one containing bleach) and a stiff bristle brush. You can also try alkali detergents and commercial emulsifying agents; apply these with a brush or spray and be sure to give them sufficient time to work. Test these chemicals on a small area that is not too visible before using them on a large area. (These compounds have the added advantage that they can be used in steam cleaners.)
For small, stubborn stains, a poultice using trichloroethylene will pull the stain from the pores. Exercise caution when using trichloroethylene in confined spaces. Ventilate the fumes.

Soot
For small areas of soot, press light-colored children's molding dough onto the brick and lift the soot away. (Be careful--you don't want to pull off any surface material.) Or dip a scrub brush into a pan of full-strength white household vinegar. Scrub a small section at a time, working up. It may take a lot of elbow grease and several applications to remove all of the soot.

Bucket and Brush Hand Cleaning
This is probably the most popular but most misunderstood of all the methods used for cleaning brick masonry. Its popularity is due to the simplicity of execution and the ready availability of proprietary cleaning compounds.

To select the proper cleaning solution (proprietary compounds, detergents or acid solutions) follow the steps outlined below:

1. For proprietary compounds, make sure that the one selected is suitable for the brick and follow the cleaning compound manufacturer's recommended dilution instructions. Brick-Anew fireplace cleaner is specially formulating for just this purpose, unlike many commercial cleansers. Although these other cleaning solutions generally perform in a satisfactory manner, you should test each product being considered in an inconspicuous spot.

2. Detergent or soap solutions may be used to remove mud, dirt and soil accumulated during construction. A suggested solution is 1/2 cup dry measure (0.14 L) of trisodium phosphate and 1/2 cup dry measure (0.14 L) of laundry detergent dissolved in one gallon (3.9 L) of clean water.

3. For acid solutions, mix a 10% solution of muriatic acid (9 parts clean water to 1 part acid) in a non-metallic container. Pour acid into water. Do not permit metal tools to contact the acid solution. There is the temptation to mix acid solutions stronger than recommended in order to clean stubborn stains. The indiscriminate use of any acid solution may tend to cause further stains.

Caution
Improper or overzealous cleaning may damage even new brick. If your fireplace brick is old and crumbling, any cleaning may cause damage. Test any cleaning material in an inconspicuous spot. To remove soot from brick that is not in good condition, mix a 50/50 solution of laundry bleach and water, pour into a spray bottle, spritz the bricks, then scrub with a soft-bristled brush. Rinse with water.

Painting Stained Brick
Fireplace bricks that are permanently stained, discolored, or damaged may not be worth the time and effort to clean. Another option is painting the fireplace brick. Although many people are opposed to painting brick “on principle,” in reality this may be your best option for unsightly or ugly bricks. Try an all-in-one fireplace paint kit for an end result that has the look of real brick.