The following information is a general guideline for cleaning clay brick. 

• Protect the base of the wall from rain-splashed mud and mortar splatter. Use straw, sand, sawdust, or plastic sheeting spread out on the ground, below the wall under construction.

• Scaffold boards near the wall should be turned on edge and angled away from the wall at the end of the day. This will prevent possible rainfall from splashing mortar and dirt directly on the completed masonry.

• Cover the top of walls with a waterproof membrane at the end of the workday to prevent mortar joint wash out and entry of water into the completed masonry.

The above steps will help prevent mortar smears and mud stains on new masonry. Where however, the masonry is marred by mortar or mud stains, this guide offers suggestions on how best to remove the marks.

Brick manufacturers recommend the bucket and brush cleaning method or low pressure washing, using methods outlined below. Both the bucket and brush and low pressure cleaning methods can be used with plain water or proprietary chemical solutions. The recommendations for cleaning agent and dilution ratio for each brick are as follows. The bucket and brush method is generally safer for brick. However, if carried out properly, low pressure cleaning can give good results.

WARNING

UNDER NO CIRCUMSTANCES SHOULD YOU  RECOMMEND THE USE OF MURIATIC (HYDROCHLORIC) ACID, HIGH PRESSURE CLEANING (ie. pressures above 1850 kpa) OR SAND BLASTING. RESIDUAL STAINING AND/OR REMOVAL OF SAND COATINGS CAN RESULT FROM THESE CLEANING METHODS.

Preparation Before Cleaning

1. Remove any defective mortar from the joints and re-point as required.
2. Dry clean the wall first, removing large lumps of mortar with a hardwood paddle or piece of the same colour brick.
3. Protect metal, glass, wood fixtures and/or landscaping where chemical solutions are to be used.

Precautions to be Taken When Chemical or Pressurized Water Method is to be Used

1. Prior to cleaning the entire building, the cleaning method should be applied to an inconspicuous area, approximately 1.5m x 1.5m (5'x5') or as agreed upon by the architect, builder and/or owner. The test area should be allowed to dry a minimum of three days before inspection.
2. Do not proceed with cleaning the entire building until the test area has been approved by the architect, builder and/or owner.
3. Do not proceed with cleaning the entire building if discoloration or efflorescence appears on the test area.
4. Contact Canada Brick and/or the cleaning agent manufacturer if there are any negative results on the test area.
5. Mortar must be cured before cleaning commences. For Type "N" mortar this usually means 7 days minimum, and for Type "S" mortar 3 days minimum.
6. It is advisable to discontinue "wet" cleaning operations by mid October to allow the masonry to dry out before the on-set of winter.

Cleaning Procedures

• Plain Water Cleaning
  • If using plain water to clean, it is most effective when performed within 24 hours of brick installation.
  • Starting at the top, saturate the wall with clean water including all masonry areas below. Wet the wall until water "stands" or remains on the surface.
  • Using a masonry bristle brush, scrub the brick face only.
  • Rinse the wall thoroughly from top to bottom using clean water.
  • Mud stains can partially be removed by following this procedure. However, the mud particles are often lodged within the pores of the brick and are difficult to remove.

• Cleaning Using Chemicals
  • WE DO NOT RECOMMEND THE USE OF MURIATIC (HYDROCHLORIC) ACID IN ANY DILUTION FOR THE CLEANING OF BRICK.
  • When using chemicals to clean new brickwork, it is important to avoid absorption of the chemicals into the body of the brick. The chemical solution should be kept on the face of the brick, where the mortar smear is. This is easily achieved by first thoroughly saturating the wall with clean water. A wet sheen should be visible on the masonry surface, and remain for a minute or so, before applying the chemical. At no time should cleaning solution be allowed to dry into the masonry. For this reason, shaded areas should be chosen for cleaning - avoid application in strong direct sunlight. If drying starts to occur, re-wet brickwork.
  • Once the wall is completely saturated with clean water, start at the top of each elevation, working in sections of approximately 3m wide by 2.5m high (10' x 8'). Clean a smaller area if the wall is drying rapidly. Apply the cleaning solution from the bottom of the section to the top. Apply the cleaning solution to the wall with a densely packed soft fibered masonry brush. Allow the cleaning solution to dwell on the masonry surface between 1 and 5 minutes, or as recommended by the cleaner manufacturer. At the end of the dwell time, reapply the cleaning solution with a scrubbing action before any rinsing.
  • Rinse the cleaned section of wall thoroughly, starting from the bottom of the section and moving to the top in a horizontal pattern following the brick coursing. This minimizes streaks and scumming which can be very difficult to remove. On hot days, try to clean shaded areas, to avoid the rapid evaporation of water.
  • If staining or efflorescence develops after cleaning, DO NOT ATTEMPT TO RE-CLEAN WITH A STRONGER SOLUTION OF THE SAME CLEANING AGENT. Contact the Brick manufacturer or the cleaning agent manufacturer in order to determine a revised cleaning procedure.
  • For best results, cleaning brickwork should be carried out between 7 and 30 days after the work is completed. Ideally the ambient air temperature should be between 10°C (50°F) and 42°C (90°F).

• Cleaning Using Pressurized Water
  • WE DO NOT RECOMMEND THE USE OF WATER PRESSURES ABOVE 4,850 kPa (700 psi). Nozzle pressure in excess of 4,850 kPa (700 psi) may damage the brick sand coating and force cleaning solutions into the body of the brick. Note that there will be pressure build up in the lines when the spray nozzle is closed resulting in an initial burst when turned on. Hence excessive pressure should be released before the nozzle is directed at the wall.
  • When using pressure washing, use steady even horizontal strokes. Random movements can result in patterns on the brick surface.
  • Thoroughly pre-soak the wall and all masonry areas below the area to be cleaned. The medium pressure of 2,100 kPa to 4,850 kPa (300 psi to 700 psi) is used for pre-soaking and rinsing. Higher pressures may damage the brick face or mortar joint.
  • Once the wall is completely saturated, start at the top of each elevation, work in sections of approximately 3m wide x 2.5 m high (10' wide x 8' high). Clean a smaller area if the wall is drying quickly. Apply the cleaning solution from the bottom of the section to the top using a low pressure of 200 kPa to 350 kPa (30 psi to 50 psi ). This eliminates the possibility of driving the solution into the body of the brick. DO NOT USE MEDIUM PRESSURE. For the application of cleaning chemicals the cleaning solution is allowed to dwell on the masonry surface between 1 and 5 minutes or as recommended by the cleaner manufacturer. Do not allow the cleaning solution to dry on the masonry.
  • The section of wall is then thoroughly rinsed starting from the bottom of the section and moving to the top in a steady horizontal pattern following the brick coursing. This will minimize streaks and scumming. The medium pressure of between 2,100 kPa to 4,850 kPa (300 psi to 700 psi) is used to rinse the section.
  • If staining or efflorescence develops after cleaning DO NOT ATTEMPT TO RE-CLEAN WITH A STRONGER SOLUTION OF THE SAME CLEANING AGENT. Contact the Brick manufacturer or the cleaning agent manufacturer in order to determine a revised cleaning procedure.
  • If pressure washing is used without chemicals, it is advisable to work from the bottom up. In this way it is easier to monitor which sections have already been completed.

Brick dust contamination

Cutting of brick on site can result in fine brick dust on the face of the brick. This is particularly noticeable with the lighter pastel coloured brick. This dust can be minimized by cutting the brick face down. This dust is not permanent and can be removed by one of the following methods:

• washing the brick with clean water and a bristle brush
• using compressed air at a pressure of approximately 100 psi

Efflorescence

Efflorescence is a crystalline deposit of water-soluble salts on the surface of masonry. Although efflorescence is unsightly and a nuisance to remove, it is not harmful to the brick masonry nor does it affect the structural integrity of the masonry. For efflorescence to occur, a number of conditions are necessary; there must be a source of water into the masonry, there must be soluble salts within the masonry, and there must be a path for the water to get to the surface of the masonry and evaporate.

Efflorescence occurs only occasionally and it is difficult to predict when it will occur. However, efflorescence is generally associated with wet and cold weather, and the early life of the building.

The source of the salts may be from either the brick or the cement and/or lime in the mortar.

Building Bloom: In new construction, efflorescence is referred to as "new building bloom," and the source of the water is the moisture within the building material during the construction period. Once the building is completed and the building components dry out to the ambient humidity level, no further efflorescence should be expected.

The removal of efflorescence is relatively easy. Efflorescence salts are water soluble and generally will disappear of their own accord with normal weathering. This is particularly true of "new building bloom." If more immediate removal is required, efflorescence salts can be removed by dry brushing or with clear water and a stiff brush. 

It is advisable to allow the brickwork to dry out completely before attempting to remove efflorescence. In extreme cases of efflorescence, a thin layer of poultice can be applied to the masonry surface after cleaning. This will draw the salts out beyond the brick surface.

Note: Power washing is not recommended as this process will drive additional water into the masonry and result in further efflorescence.

Note: If efflorescence occurs repeatedly, it is an indication of excess moisture in the brickwork. The source of this moisture must be identified and eliminated to reduce further problems.

Lime Weeping or "Bleed": This is a rare phenomenon. Unlike normal efflorescence, which is deposited as a thin surface layer, lime weeping builds up to form a thick encrustation in a localized area. It usually occurs at joints, cracks or base wall flashing level. Lime weeping is more difficult to remove.

Recommended Cleaning Agent and Dilution

A) 600 Detergent (1-6) or VANA-TROL (1-6) or similar
B) VANA-TROL (1-8) or similar

Note:

1. With all coloured mortars use VANA-TROL only.
2. Numbers in brackets (ie. 1-6) refer to 1 part cleaner to 6 parts water.

We carry both 600 Detergent and Vana-trol in stock.

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Last modified: December 09, 2008