Paint does more than change the appearance of a building. In some cases, it can quietly contribute to long-term damage, especially when applied to masonry surfaces. While paint might seem like a simple finishing touch, the type of coating used on a brick or stone facade can have serious consequences for the building’s integrity.
One of the most common but avoidable issues we see in the field involves non-breathable paint applied to masonry surfaces. These coatings trap moisture, prevent proper drying, and accelerate deterioration beneath the surface. In many cases, the damage does not become visible until the underlying material is already compromised.
This article breaks down why breathability matters, how improper coatings lead to damage, and what property owners and facility managers should consider when maintaining or restoring masonry facades.
What Is Non-Breathable Paint?
Masonry materials like brick, block, and stone are porous. They naturally absorb and release moisture through vapor diffusion. This breathability is essential for the long-term performance of the wall system, especially in climates with freeze-thaw cycles.
Non-breathable paint refers to coatings that do not allow moisture vapor to pass through. Common examples include:
- Acrylic or latex-based paints
- Elastomeric coatings
- Oil-based paints
While these products may offer water resistance or flexibility, they also seal the surface completely. When applied over masonry, they prevent moisture from escaping. Instead, water becomes trapped within the wall system, where it can freeze, expand, and damage the material from the inside out.
Even small amounts of moisture from rain, humidity, or interior sources (like condensation) can cause problems when sealed behind non-breathable paint layers.
7 Symptoms of Paint-Related Masonry Damage
Non-breathable coatings don’t just seal in moisture, they create pressure inside the wall system that the masonry can’t release. That pressure shows up in specific, often destructive ways. Here are the most common signs we see in the field:
1. Surface Cracking or Bubbling in the Paint Layer
Moisture trapped behind the coating tries to escape, building pressure between the paint and the masonry surface. This causes blistering, bubbling, or visible cracks in the paint. These are often early signs of deeper problems beneath.
2. Chunks of Paint and Surface Material Detaching
As pressure increases, large areas of paint and sometimes outer layers of masonry begin to peel or shear off. This isn’t just cosmetic, it’s evidence of stress building behind the surface.
3. Brick or CMU Displacement from Internal Moisture Expansion
Trapped moisture can expand and shift masonry units out of place. You might see misaligned bricks or blocks, especially near horizontal seams or where coating is applied heavily.
4. Bowing or Bulging Walls
When internal pressure has nowhere to go, it can force whole wall sections outward. This is especially common in CMU or composite systems and often requires significant reconstruction.
5. Facade Cracks and Shifting Joint Lines
As the wall system moves under pressure, you may notice diagonal or stair-step cracks, distorted mortar joints, or separating facade sections. These are signs of structural stress, not just aging.
6. Interior Water Intrusion
If moisture cannot escape through the exterior, it may travel inward, leading to stained drywall, damp insulation, or visible water leaks inside the building.
7. Localized Material Failure
Eventually, weak points give way. This can include small wall collapses, partial veneer detachment, or complete failure of individual masonry sections under pressure.
In many of these cases, the paint layer may appear intact for years, until signs of failure begin to show. The deterioration can be subtle at first, but once it accelerates, the cost and complexity of repairs increase quickly.
Appropriate Coatings and Treatments for Masonry
If you’re considering painting a masonry building, or working on one that has already been coated, it’s important to take the right approach.
First, determine whether the existing coating is causing damage. Look for signs like peeling paint, efflorescence, or surface cracking. If moisture-related issues are present, it’s best to remove non-breathable coatings before further repairs or restoration.
If a coating is required for aesthetic or protective reasons, only use breathable, vapor-permeable products designed for masonry. Options include:
- Mineral silicate paints
- Limewash or lime-based coatings
- Specialized masonry stains or breathable sealants
These products allow moisture vapor to pass through the wall while still providing surface protection. Always consult product specifications to confirm vapor permeability ratings, and never apply a coating that seals the wall without a moisture management plan.
When to Call a Professional
Identifying and correcting coating-related damage often requires a deeper evaluation. In many cases, moisture has already affected the materials below the surface. Restoration professionals can test the wall for moisture content, assess bond conditions, and determine whether selective repair, removal, or full replacement is needed.
A qualified contractor will also understand how to safely remove coatings without damaging underlying brick, block, or stone, and will be able to recommend breathable alternatives when recoating is necessary.
About Building Restoration Corporation
With over 40 years of experience in exterior building repair and restoration, Building Restoration Corporation specializes in masonry preservation, including sensitive coating removal, tuckpointing, and facade stabilization.
We are not a paint contractor. We are a team of skilled professionals who understand the materials we work with, and how to preserve them for the long term. From historic buildings to modern commercial properties, we approach every project with a focus on durability, safety, and detail.
Schedule an Evaluation
If your building has been painted and you’re noticing signs of deterioration, or if you’re planning a restoration project and need expert input, our team can help.
📞 Call us at (612) 789-2800
📧 Email: info@buildingrestoration.com
🔗 Request a building evaluation https://www.buildingrestoration.com/services/building-evaluation/
