Brick Cleaning Techniques, Cleaning New Brick
The process of cleaning brick is often one of the most overlooked aspects of brick construction. The finest craftsmanship can be ruined by improper cleaning techniques, leaving behind stains, streaks and etched mortar joints. It is very important to follow the proper construction techniques and proper cleaning procedures.
Some possible problems resulting from lack of adherence to the following construction tips include:
* Reduced aesthetic appeal of the finished product which will create angry owners and architects.
* Potential owner back charging, re-doing the work, or withholding of payment.
* Owners and architects will tend not to use masonry in their future projects if masonry does not live up to expectations of great aesthetic value.
Minimizing the Need for Cleaning
Masonry can be cleaned much more easily if certain steps are taken during construction to keep the job as neat as possible. Craft workers should make sure the mortar they use is of the proper consistency; if it is too wet, it will tend to smear the masonry units. If the mortar isn’t thumbprint hard before it is jointed, brushed and retooled, the wall will be smeared and messy and it will requires a great deal of effort to clean. That extra effort could lighten or bleach the color of the mortar joints on one part of the building to the degree that those joints will stand out from the joints on another part of the building.
Brick or tile walls should be covered at the end of each work day to prevent excessive moisture from entering the cavity. Eventually, that moisture may leach out towards the exterior; drawing soluble salts to the face of the brick. This could result in efflorescence; deposits of white powder or crust on the surface of the masonry. The scaffolding planks closest to the wall should be turned on their sides at night to avoid the possibility of water splashing onto the mortar, and then on the wall, during an overnight rain storm.
Brick Cleaning Problems
Experienced mason contractors and craftworkers realize that selecting the proper cleaning solution and the proper cleaning method is very important to the outcome of the finished product. The small amounts of different minerals found in many masonry units, especially brick, will react with some cleaning solutions in a negative manor and cause stains and blemishes that may actually ruin the appearance of the entire structure. Mortars that contain iron oxides as coloring agents cannot be cleaned with just “any” cleaner. Manufacturers of brick, mortar coloring agents, and cleaning products make specific recommendations for the cleaning of masonry structures. Follow these recommendations closely. There are three basic methods of cleaning new masonry that will be presented in this website;
*Bucket and Brush Hand Cleaning
*Pressurized Water Cleaning
Remember that some of the chemicals used to clean masonry are hazardous. Before starting to wash brick, be sure you are wearing the proper protective clothing and safety gear, and check the work area for proper ventilation. Be certain that you have been properly trained to handle the chemicals and cleaning equipment. Keep in mind that some of the chemicals you may use during the cleaning process are regulated by governmental agencies; you are responsible for the proper use and disposal of these products.
It’s good practice to build a test panel prior to cleaning the structure’s actual walls. The proper dilution of the appropriate cleaning solution can be applied to the test panel to see what happens. If the wrong products or dilutions have been used, they’ll bleach the mortar or etch the joints or both. Some minerals in brick may react with cleaning solutions and the result will show up as stains on the units or on the mortar. It’s also a good idea to build that test panel as soon as the job is started, so that cleaning solutions can be applied to it well before the actual job is finished. If the test panel cleans up properly with the methods and chemicals being used, chances are good the walls will also clean up properly.
Timing is critical. Manufacturers of cleaning solutions recommend waiting at least seven days before applying their products. But leaving scaffolding in place for extra weeks or a month is expensive and may not even be possible. Many contractors are forced to start the cleaning process within two days of completing the actual construction. Cleaning up so close to completion means that even more stringent precautions need to be taken, because there is a strong possibility that the mortar joints might be etched or that color might be removed from the joints.
Be sure to use plenty of water. The walls that are to be cleaned should be saturated with clean water prior to placing any cleaning solution on them. If the walls are not wet, the cleaning solution may dissolve the mortar stains and deposit them within the pores of the masonry units, making them nearly impossible to remove. After the wall is cleaned, it needs to be thoroughly rinsed. If it isn’t, the wall may dry with a streaked appearance.
Bucket and Brush Hand Cleaning
Standard bucket and brush methods are the most popular ways to clean masonry and can produce excellent results. Here are the steps to follow:
1. Obtain the cleaning recommendations of the brick, mortar and cleaning product manufacturers.
2. Select the proper product.
3. Select the proper dilution ratio.
4. Before mixing or applying chemicals, make sure you are wearing the proper safety gear; including goggles and gloves.
5. Use the recommended cleaning procedure on a sample test panel or area to see what happens.
6. Remove large mortar particles from the walls with a wooden paddle or non metallic scrape hoes or chisels.
7. Protect surrounding surfaces, such as metal, glass, wood, limestone and cast stone surfaces. Mask windows, doors and areas with ornamental trim.
8. Saturate the area to be cleaned with water.
9. Starting at the top of the wall, apply cleaning solution with a long-handled, stiff fiber brush. Follow the cleaning manufacturer’s recommendation for the amount of time the solution should be allowed to remain on the wall.
10. Scrub vigorously with the brush.
11. Rinse thoroughly. Flush the walls with large amounts of clean water before they dry. If you do not flush the wall completely, white scum may form on the it.
Mud, dirt and soil may be most easily cleaned off of new brick masonry with detergent or soap solutions. Try 1/2 cup of trisodium phosphate and 1/2 cup laundry detergent dissolved in a gallon of water. For an acid solution, mix nine parts clean water with one part muriatic acid. Always pour the acid into the water. Don’t use a strong acid solution; it might cause further stains.
12. Rinse the wall thoroughly with clean water from top to bottom and make sure all the cleaning solution has been removed.
To save time and labor costs, many contractors use pressurized water to clean new masonry. The base unit can
be 100 feet away from the units being cleaned if long hoses, pressure guns and special nozzles are used. Some systems have two hoses, one for water and the other for cleaning solutions.
If not used carefully and within reasonable boundaries, water pressure cleaning can damage masonry. The sand finish on some units can be removed entirely by water pressure, resulting in a wall that looks different than its designer intended. Nozzle pressure in excess of 700 psi may damage brick units and erode mortar joints. Note that pressurized cleaning probably will change the appearance of sand molded brick, brick with glazed coatings and sand faced extruded brick.
To clean brick masonry with pressurized water; follow these procedures:
1. Obtain the cleaning equipment and cleaning solution and test them on sample areas. Make sure the solution you are using is compatible with the equipment. Mix according to the manufacturer’s directions.
2. Presoak the wall. Remove large particles by hand or with wooden paddles. Saturate the brickwork to prevent it from absorbing the chemicals.
3. Apply the cleaning chemicals through the pressure cleaning unit.
4. Allow the solution to remain on the wall for about five minutes.
5. Starting at the top, rinse thoroughly. Flush the walls with large amounts of clean water before they dry.
Some contractors prefer to clean masonry with dry sandblasting because it eliminates the problem of chemical reaction with vanadium salts and other materials used in the manufacture of brick.
If done improperly, however; sandblasting may scar the face of brick units and mortar joints. Sanded, coated, glazed, and slurry finished brick should not be sandblasted.
Tools of the sandblaster include a portable air compressor; blasting tank, blasting hose, nozzle and protective clothing and a hood for the operator. The air com- pressor produces 60 to 100 psi at a minimum air flow capacity of 125 cubic feet a minute. Sandblasting uses a variety of materials to achieve various degrees of cutting or cleaning. These include silica sand, crushed quartz, crushed granite, white urn sand and even crushed nut shells.
To clean brick by sandblasting:
1. Pick sandblast materials that are clean, dust free and abrasive.
2. Make sure the brickwork is dry and well cured.
3. Remove large mortar particles by hand with wooden paddles and non-metallic scrape hoes or chisels.
4. Protect non-masonry surfaces near the areas being cleaned.
5. Test clean several areas at different distances and angles that product the most effective cleaning without damaging brick or mortar. Direct the materials at the masonry units, not the mortar joints.
If dissolved mortar or dirt is allowed to remain on dark brick (red, red flash, brown or black) the stains they cause are likely to show up as light gray, brown or yellow discolorations. The bucket and brush method with nothing more complex than a solution of a half cup of trisodium phosphate and a half cup of household detergent per gallon of water may do the job.
If not, a solution of one part hydrochloric (muriatic) acid to nine parts water may work. Be sure to pour the acid into the water; not the water into the acid. Be careful and rinse the wall and surrounding areas completely when you are finished.
Light colored brick can also be successfully cleaned with the trisodium phosphate and detergent mix. But since these pink, grey, and buff brick are more likely to be burned by acid than darker brick, you should avoid using it.If you have to use acid, use a weaker mix.