All buildings need their exterior to be inspected periodically for damage and deterioration. When the necessary general maintenance is being carried out, consideration should be given to cleaning the exterior, including the wall surfaces. This is part of the life cycle cost of any building as a good surface clean can often restore the appearance of the Terraco EIFS.

Terracoat Textured Coatings offer many long term advantages for ease of cleaning when compared to other types of exterior wall cladding. Just as one regularly cleans a window, similarly periodic cleaning of an exterior wall coating improves its long-term appearance.

Terracoat Textured Coatings are the most popular type of EIFS finish, along with Terralite Stone Simulation Coatings. These decorative finishes are safely and most effectively cleaned using general cleaning compounds, or alkali based synergistic detergents, which are then rinsed off the wall using a low pressure water mist spray. These products will remove most usual surface dirt and contaminates. Acidic cleaners are not recommended for the cleaning of Terracoat or Terralite coatings.

Every building will need to be dealt with on merit as each has its own set of specific challenges and requirements. In most instances these general purpose cleaners will be satisfactory. However, some environments present challenges which require more specialised cleaners. Under these circumstances, it is recommended that the cleaning detergent manufacturer be consulted for more specific technical advice.

Cleaning Procedures

Prior to commencing any cleaning project Terraco recommends:

  • Consulting with the cleaning detergent manufacturer for their specific cleaning method statements and procedures;
  • Testing the effectiveness of the chosen cleaning agent on a small and isolated area of the wall coating prior to commencing with cleaning on a large scale.


1. Preparation

  • Protect all property and surfaces not intended for cleaning from splash, residue and wind drift.
  • Cleaning effectiveness is reduce when the surface and air temperature falls below 10˚C or is above 40˚C.
  • Protect grass and plants by covering or spray from sprinklers.
  • Contact the cleaning detergent manufacturer for more information about their recommended protection precautions.


2. Cleaning Equipment

  • It is not recommended leaning a ladder against any wall coated with a textured wall coating as it may cause surface damage.
  • The high pressure spray can damage most materials and the surface of the textured wall coating. If using high pressure spray equipment, please ensure that it is set as a low pressure mist spray. Also ensure that the angle of the nozzle tip to the surface is not so acute that the pressure strips off the wall coating from the substrate. An angle tip of 45˚ or greater must be used to prevent damage to the finish. Take care when using near sealant joints and wood trim.
  • For commercial projects, pressurised water spray systems are used – a compressor along with a nozzle equipped spray gun - for both pre-wetting and rinsing. Other systems have two pipes, one with cleaning detergent and the other clean water. Mobile units are more convenient for moving around on site.
  • For residential projects, the simplest way of providing a low pressure water rinse is by using a garden hose, for both pre-wetting and rinsing.


3. Cleaning Method

a. Pre-soak the Wall

  • It is necessary to thoroughly wet the area to be cleaned prior to the application of the cleaning material by using either a garden hose or pressurised spray equipment.
  • The surface to be cleaned must be wet when the cleaning detergent is applied.
  • Some cleaning detergent manufacturers recommend that you clean from the bottom up, while others recommend from the top down. Nevertheless, lower areas must be regularly saturated with water in order to prevent absorption of run-off from above, which can leave ‘clean streaking’. Application of vertical sections is also usually recommended.
  • Steam cleaning, or even using hot or warm water, is not recommended as this may cause the finish to soften, and may result in the removal of the finish.


b. Cleaning Detergent Application

  • Mix cleaning solution in accordance with manufacturer’s instructions.
  • Test the prepared mixture for effectiveness on all surfaces that may come into contact with the solution during the application and rinsing process.
  • Check all equipment for compatibility with the type of cleaning detergent and check with the manufacturer for more information on cautions for use.
  • Application of the cleaning detergent can be done either: Manually - Brush lightly using a soft bristle brush to generate low foam; or Spray - Use low-pressure (30-50 psi / 200-350 kPa) to coat the surface to be cleaned, light scrubbing using a soft bristle brush may be necessary in stubborn areas, and never use high pressure as this can drive the solution through the finish int0 the base coat and cause future staining.
  • Follow instructions from the manufacturer of the cleaning detergent regarding the period of time the cleaning detergent is left on the surface prior to rinsing off as environmental elements (heat, wind, direct sunlight) effect the surface drying time and reaction time to cleaning detergents. Ensure that the cleaning teams work in shaded areas to avoid rapid evaporation.
  • Wear protective equipment at all times in order to comply with local Health and Safety Regulations.


c. Water Rinsing

  • Rinse the wall with copious amounts of clean water from top to bottom, by using either a garden hose or pressurised spray equipment, before the cleaning solution can dry.
  • All areas below the cleaned area must also be rinsed down thoroughly in vertical sections to avoid residues.
  • Rinse all tools and equipment with water after each use.
  • Sometimes higher pressure (not more than 600 psi / 4000 kPa) is needed to remove surface contaminants lifted by the cleaning detergent. This does not mean ‘power washing’ the surface as this may damage the surface.


4. Other Cleaning Issues

Over and above the removal of surface dirt and contaminates, cleaning product manufacturers produce materials that are formulated for the removal of specific types of staining, including stubborn dirt, grime, grease, oily substances, smoke / soot, industrial pollution. The treatment of rust marks on a wall surface from an air conditioner, a handrail etc. are usually the most challenging. Please consult with a manufacturer of cleaning detergents appropriate for these types of stains.

A few of the most common cleaning issues on site relate to:

a. Fungi and Algae Growth

Fungi and / or algae organisms usually grow where there is adequate dirt or moisture, accompanied by favourable temperatures and humidity.

It must be treated, and neutralised, using Terraco Sterilising Solution as per Technical Data Sheet. If recoating is planned, such treatment must be performed prior to the application of the new wall coating.

b. Efflorescence

While efflorescence does minimal damage to the coating, its appearance results in the coating looking unsightly.

Efflorescence occurs whenever the surface below the coating contains cement, which as water migrates through the cementitious material it interacts with the salts present in it. When the water containing the salts reaches the surface, it evaporates leaving a white salty deposit behind on the surface. This phenomenon is easier noticed on darker surfaces.

It is recommended that a general cleaning detergent is used with pressurised water to remove light deposits. For heavy efflorescence, an extremely diluted acidic solution may be required. In rare cases diluted vinegar water is known to solve the problem. Otherwise consult the manufacturer under such circumstances.

c. Other Stains

It is recommended that a qualified expert be consulted in these instances as unknown stains may require laboratory tests in order to determine their composition and treatment method.


Once the Terracoat or Terralite has been cleaned, the use of Terraco Kode 8, a new generation of clear topcoat, to enhance dirt pick-up resistance of exterior coating systems is recommended.

Terraco Kode 8 is based on innovative nano technology which ensures enhanced dirt pick-up resistance, outperforming all other products in its class. Terraco Kode 8 has excellent resistance to weathering and is non-yellowing. Contact your nearest Terraco representative for more information.