Proper Cleaning Techniques for Maintaining EIFS in Ontario

Exterior Insulation Finish Systems are a popular exterior wall cladding system. Sometimes referred to as synthetic stucco, EIFS are not the same as stucco but are instead pieces of layered, lightweight coating, not a cement-like mixture. EIFS have been increasingly growing in popularity for a multitude of reasons, particularly their aesthetically pleasing nature. However, EIFS’ tendency to attract dirt, mould, rust and show salt deposits easily is a concern. Because EIFS do not have the same hardness as stucco, more specialized methods have been adapted to clean and maintain them properly. The main type of EIFS is the barrier form, which consists of three layers – foam insulation, a cementitious acrylic base coat that is reinforced with fiberglass mesh, as well as a finished top coat. This top coat is usually made with acrylic or other resins.

Because the top coating of the EIFS is usually textured, it can become soiled with foreign particulate matter that may be difficult to remove without harming the look of the EIFS. As well, the finish of EIFS can react to moisture and soften, absorbing some of the dirt and bringing it slightly within the surface of the material.


Before the need to clean EIFS arises, some general maintenance can be undertaken to prevent it from becoming soiled or remove the possibility of the introduction of excess moisture which allows for the possibility of mold and mildew growth. Preventing leaks around windows and doors is key to prevent the weakening of your EIFS so it can be cleaned properly. Sprinklers, plants and gardens that are watered periodically are all sources of moisture that can help dirt stick to the EIFS. Because installing EIFS is not a recommended do-it-yourself task for homeowners but cleaning it can be, providing homeowners with information on how to clean it properly can help keep it looking great long after its installation.

It becomes apparent that only particular patches of the EIFS are becoming dingy as time goes on, perhaps because rain is constantly deflected onto it or it’s in a high-trafficked area, a clear acrylic coating can be applied, effectively sealing up the area and preventing more dirt from becoming embedded within it. Note that this method should only be used on the small affected area.

Painting EIFS

Painting over the soiled EIFS might seem like the easiest option. However, the heavy-duty paints that would be necessary to use can actually seal the EIFS too much and keep moisture too close to the building and insulation, creating a vapor barrier. These paints can also contain powerful solvents that can erode the EIFS. Many producers of EIFS make paint specifically for providing a protective coating.

Using Detergents

Applying a detergent and letting it do most of the work is one of the best bets with regards to properly and safely cleaning EIFS, and these can be rinsed off carefully with a pressure washer on its lowest setting or even better, a garden hose. If the pressure washer is too forceful, it could harm the finish or result in water going through the EIFS. Sandblasting and solvents are also out when it comes to cleaning EIFS, as they can ruin the finish. There are many commercially or industrially available EIFS cleaners, even a mixture of 1/3 of a cup borax (a commercially available sodium tetraborate cleaner), a bit of liquid dish soap and a litre of household bleach can be effective. Industrially, one of the easier and gentler detergents to use is one that is trisodium phosphate-based. It can be gently applied with a soft scrub brush and then rinsed off. Any cleaner or detergent being used should be mixed as per the directions, and pay attention as to any materials stated on the container that the cleaner is not meant to be used for or that it can harm.

Salt and efflorescence

Salt and efflorescence are both white, crystalline deposits on the outside of a home or building. In Toronto and much of southeastern Ontario, pretty much everything is affected by salt in the winter. Shoes, pants, cars, and even EIFS are often coated in salt during the colder months. This salt is a product of snow-melting efforts on roads and sidewalks, but eventually this salt gets tracked everywhere.

Efflorescence on the other hand, is the result of moisture drawing out salts from within concrete. When the water evaporates, it leaves these deposits behind. Both snow-removal salts and efflorescence can be brushed off by hand, or they can be rinsed off with clean water, a water and vinegar solution or specialty salt-removal cleaners.

Rust & Mould

There are specialty cleaners available for removing rust from EIFS. However, if the originating source of the rust is not removed, it will only come back, even through paint if it has been painted over. Usually this rust is caused by improper screws or nails that were used to install the EIFS, and the only way to stop the rust from coming back is to remove the nail or screw, which means removing the EIFS. Rust does not pose any risks to EIFS, so the decision to remove the nails is only aesthetic.

A diluted bleach and water solution can also be applied to kill and remove any mould or algae growth, but make sure to dilute it sufficiently and not let it sit for prolonged periods of time as to not harm or lighten the finish of the EIFS.

Paint & grease

Non-specialty cleaners or solvents may eat away or harm the finish of the EIFS. In the case of accidental painting or oil stains, a specialty cleaner specifically for cleaning EIFS should be used.

Safe to use cleaning methods on EIFS

  • specialized EIFS cleaners
  • light detergents such as dish soap
  • water and vinegar
  • diluted bleach
  • borax
  • pressure washers on low settings
  • soft-bristled brushes

Always ensure cleaners and detergents are mixed as per the directions on the container.

Not safe to use cleaning methods on EIFS

  • paint or rust removing solvents not meant for EIFS
  • sandblasting
  • pressure washers on high settings
  • steam (it can melt the insulation)
  • heavy duty paints

The soft exterior finish of EIFS are what makes it especially susceptible to dirt and other undesirables. Because effective methods that will bring the dirt out of the top coat but also not harm it need to be deployed, special considerations need to be taken when cleaning EIFS. EIFS is generally maintenance free, but cleaning EIFS properly will increase its lifespan and keep it both functional and looking beautiful for years to come.

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