What are some signs of paint failure on a home's exterior?

Signs of exterior house paint failure can range from cosmetic issues to indicators of deeper moisture problems. Catching these signs early is key to preventing more extensive damage to your home's siding. 

Here are the common signs of paint failure you should look for during inspections:

1. Peeling and Flaking 

This is the most obvious and widespread sign of paint failure. Peeling occurs when the paint film loses its adhesion to the surface beneath it. 

• Appearance: Edges of paint lift from the surface, often curling outward or flaking off in chips.

• Cause: Usually caused by moisture intrusion, improper surface preparation, or using the wrong type of paint (e.g., oil-based paint over a moist surface). 

2. Cracking and Checking

Cracking occurs when the paint film loses its flexibility and cannot expand and contract with the changing temperatures of the siding material. 

• Appearance: Fine, hairline cracks ("checking") or deeper cracks ("alligatoring") that break through the top layer of paint.

• Cause: Often a result of aging paint becoming brittle, poor preparation (too thick layers), or extreme temperature fluctuations. 

3. Blistering 

Blistering refers to bubbles forming under the paint film, ranging from small pinpricks to large pockets. 

• Appearance: Raised bumps or bubbles on the paint surface that eventually burst and peel.

• Cause: Typically caused by moisture (either from rain seeping in or moisture vapor from inside the house) getting trapped behind the paint and expanding when heated by the sun. 

4. Fading and Chalking

While less severe than peeling, these are signs that the paint's protective properties are breaking down due to UV exposure. 

• Fading: The color appears washed out or drastically different from when it was first painted.

• Chalking: A fine, powdery substance appears on the surface when you run your hand across it. This is the paint's binder breaking down.

• Cause: Normal aging and breakdown of the paint's resins from sun exposure. While some chalking is normal for certain paint types, excessive chalking means the paint is no longer protecting the substrate. 

5. Mildew and Mold Growth

These organic growths indicate consistent moisture issues. 

• Appearance: Black, gray, green, or brown spots/stains on the paint surface, often in damp or shaded areas (e.g., under eaves or on the north side of the house).

• Cause: High humidity, poor ventilation, and the presence of organic material on the paint surface. 

6. Stains and Discoloration

• Water Stains: Brown, yellow, or white streaks often found beneath windows, gutters, or eaves, indicating water is running down the house in consistent paths and carrying contaminants.

• Rust Stains: Orange or brown stains around metal components like nails or flashing, indicating the metal is corroding and needs attention. 

If you notice any of these signs, it is time to inspect the area further, identify the root cause of the failure (e.g., a leaky gutter, no house wrap), and plan for a repaint with proper surface preparation. 

Signs of paint failure on a home's exterior are visual indicators that the protective coating is no longer performing its job and that the underlying material may be vulnerable to damage. 

Common signs of paint failure include:

• Peeling and Flaking: This is the most obvious sign of paint failure, where the paint film lifts and separates from the underlying surface. It often indicates that moisture has gotten behind the paint or that the surface was not prepared properly before painting.

• Cracking (and Alligatoring/Checking): Fine, hairline cracks that expand over time are a clear sign of a loss of elasticity. A more severe form, "alligatoring," resembles the scaly pattern of reptile skin and usually occurs when a hard coat of paint is applied over a more flexible one, or due to age and sun exposure.

• Fading and Discoloration: The sun's UV rays break down the paint pigments over time, causing the color to dull, lighten, or become uneven. This not only looks bad but also signals that the paint's protective properties are diminishing.

• Chalking: This occurs when the paint's binder breaks down due to weathering and UV exposure, leaving a fine, powdery residue on the surface that you can wipe off with your hand. While some chalking is normal, excessive chalking means the paint is no longer a protective barrier.

• Blistering/Bubbling: Small- to medium-sized bubbles or blisters forming beneath the paint film indicate trapped moisture (from interior humidity or exterior sources) or that the paint was applied on a hot, damp surface.

• Mold, Mildew, and Stains: Dark green, black, or brown spots on the surface indicate mold or mildew growth. Other stains can include reddish-brown rust streaks from metal fasteners or white, crusty salt deposits (efflorescence) on masonry surfaces.

• Wood Rot or Substrate Damage: When paint fails completely, the underlying material is exposed to the elements. Soft spots or visible rot in wood siding, trim, or fascia are signs that the paint failed to prevent moisture intrusion, leading to potentially costly structural damage.

• Failing Caulk: Look for cracked, shrinking, or missing caulk around windows, doors, and trim. Caulk seals vulnerable gaps, and its failure allows water and drafts to penetrate the home.