5 Common Exterior Stains & How to Spot Them

When it comes to your Sacramento home’s curb appeal, exterior stains are more than just an eyesore—they can lead to long-term damage if ignored. Whether on your driveway, siding, deck, or patio, stains often signal the presence of contaminants like mold, oil, or rust, which can erode surfaces, attract pests, or trigger allergies.

Fortunately, with the right exterior cleaning solutions, you can tackle even the toughest grime. Here's how to spot five of the most common culprits before they cause lasting damage. 

1. Oil Stains

Where you’ll find them: Driveways and garages

How to spot them: Oil stains are dark brown or black, often with a greasy texture. They typically appear under parked vehicles and can penetrate deep into porous concrete. If the area remains slick or oily even after scrubbing, it's likely oil.

2. Rust Stains

Where you’ll find them: Concrete, metal fixtures, sprinkler areas

How to spot them: Rust stains range from orange to reddish-brown and often streak downward, especially under metal railings or fixtures. They can be caused by metal oxidation or iron-rich water from irrigation systems.

3. Algae

Where you’ll find them: North-facing siding, shaded patios, sidewalks

How to spot them: Algae appears as green or black slimy patches. It thrives in damp, shady areas and can become slippery when wet. A musty odor often accompanies larger infestations.

4. Mildew

Where you’ll find them: Siding, wooden fences, decks

How to spot them: Mildew is typically gray or white and powdery in texture. It prefers humid environments and can grow rapidly in areas with poor airflow. If you notice a slight musty smell and discoloration that worsens after rain, it could be mildew.

5. Tannin Stains

Where you’ll find them: Wood decks, fences, and areas under trees

How to spot them: Tannin stains result from leaves, bark, or wood seeping tannic acid. These stains are brown or rust-colored and can appear in drip-like patterns. On wood, they may be mistaken for water damage.

When DIY Isn’t Enough

While some stains can be treated with store-bought cleaners, others require a deeper, more professional touch. If stains return quickly, cover large areas, or if surfaces like siding or decks are starting to degrade, it's time to call the pros. Whether it's house washing, fence cleaning, or patio restoration, professionals have the tools and eco-safe detergents to do the job right.

When you’re ready to restore your exterior to like-new condition, trust Sacramento's superior choice for pressure washing. At Rob & Son Soft Wash LLC, we specialize in effective, long-lasting exterior cleaning solutions that protect your home and boost its value.

Time to Take Action

Don’t let stains ruin your home’s beauty or integrity. For expert pressure washing in Sacramento—whether it's your driveway, siding, or deck—contact Rob & Son Soft Wash LLC today and experience the difference of professional care.