When it comes to cleaning the exterior of a building, especially one with masonry or historic materials, choosing the right cleaning method is important. Two of the most common options are pressure washing and what’s often called chemical cleaning. While that term can raise concerns, it refers to the use of professional-grade cleaning solutions specifically formulated for masonry-designed to be safe, effective, and appropriate for the material being treated.
In this article, we’ll break down the differences between these two approaches and help you determine which method is right for your building.
Pressure Washing Facades
Pressure washing is widely used for exterior cleaning, but it’s not always ideal for masonry facades. While it can quickly remove surface grime, it’s more aggressive than other methods and can do more harm than good when used on historic or aging materials.
Where it may be appropriate:
- Cleaning newer or reinforced masonry
- Non-sensitive, durable substrates
- General upkeep on commercial facades
Potential issues to watch for:
- Can erode mortar joints
- May damage softer or historic bricks and stone
- Doesn’t remove stains or embedded pollutants
Chemical Cleaning Facades
Chemical cleaning refers to the use of specialized, masonry-safe solutions to break down and remove stains, soiling, and other contaminants from building facades. These solutions are carefully chosen for their effectiveness and material compatibility.
When it works well:
- Cleaning historic or delicate masonry
- Removing carbon staining, atmospheric pollution, or paint
- Restoring appearance without damaging the surface
Why it’s often the better choice for facades:
- Non-abrasive and low-impact
- Tailored to specific masonry types and conditions
- Can reach into porous surfaces without mechanical damage
A Note on Safety and Sustainability
While the term “chemical” can sound harsh, the cleaning agents used in masonry restoration are carefully selected for both performance and safety. At BRC, we use low-toxicity solutions that meet environmental and industry standards. These products are designed to protect surrounding surfaces, landscaping, and air quality while effectively cleaning the building facade.
At BRC, we use low-toxicity solutions that meet environmental and industry standards.
How to Decide Which Method to Use
Every building is different. The age of the masonry, type of material, condition of mortar joints, and extent of soiling all factor into which cleaning method is appropriate.
If you’re working on a newer commercial building with modern materials, pressure washing may be fine for general maintenance. But for historic buildings or masonry with existing wear, a low-impact solution-based approach is often the safer and more effective choice.
Keep in mind that masonry facade cleaning may not always be permitted depending on local guidelines. Some buildings fall under the oversight of a Historic Preservation Commission (HPC), State Historic Preservation Office (SHPO), or the National Park Service, which may restrict certain methods or require approval before cleaning begins.
Talk to a Professional
Choosing the right cleaning method isn’t just about appearances-it’s about protecting the material and extending the life of your facade.
At Building Restoration Corporation, we assess the condition and material of every building before recommending a cleaning approach. If you’re unsure which method is right for your facade cleaning, our team is here to help.
