Your patio should be a place to relax, entertain, and enjoy the outdoors. But over time, dark spots, green patches, and slick areas can creep across the concrete, making it look neglected and feel unsafe to walk on. If that sounds familiar, you're likely dealing with mildew on concrete.

Mildew and algae are common on patios across North Texas, especially in shaded areas and places that stay damp. The good news is that professional pressure washing can make a dramatic difference. In this guide, we'll explain what mildew on concrete looks like, what causes it, why it's worth removing, how pressure washing helps, and how to keep it from coming back.

What Does Mildew on Concrete Look Like?

Several types of growth can show up on concrete surfaces:

Mildew

Mildew often appears as gray, black, or dark spots and patches. It can make concrete look dirty and stained, especially in shaded areas.

Algae

Algae usually looks green and can feel slimy when wet. It often grows in damp spots that don't get much sun.

Moss

Moss looks fuzzy and green and tends to grow in cracks, joints, and heavily shaded areas.

All three can make your patio look old and neglected, and all three can make concrete slippery.

Why Mildew Grows on Concrete

Concrete Is Porous

Concrete has tiny pores that absorb and hold moisture. That moisture gives mildew and algae the conditions they need to grow.

Shade

Patios shaded by trees, covered roofs, fences, or the side of your home don't get enough sun to dry out quickly. Shaded areas are one of the most common places for mildew to grow.

Moisture From Sprinklers

Sprinklers that spray patios keep the concrete damp, encouraging growth.

Poor Drainage

Low spots where water collects after rain stay wet longer and are prime areas for mildew and algae.

Overflowing Gutters and Downspouts

When gutters overflow or downspouts empty onto your patio, those areas stay damp after every rain.

Organic Debris

Leaves, pollen, and other debris trap moisture and provide nutrients for growth.

Humid Weather

North Texas can get humid, especially after storms, which keeps surfaces damp longer.

Where Mildew Shows Up Most

• Covered patios that rarely get direct sun
• Patios under trees
• Pool decks that stay damp from splashing
• North-facing areas of your property
• Walkways along the shaded side of your home
• Areas near downspouts and sprinklers
• Under patio furniture and planters

Why You Should Remove Mildew on Concrete

Safety

Mildew and algae can make concrete slippery, especially when wet. That's a concern for kids, older family members, guests, and anyone walking barefoot near a pool.

Appearance

Dark spots and green patches make your patio look neglected and take away from your outdoor space.

It Spreads

Left alone, mildew and algae can continue to spread across your patio.

Staining

The longer growth sits on concrete, the more likely it is to leave stains behind.

Enjoying Your Outdoor Space

A clean patio feels more inviting for family time, cookouts, and relaxing.

How Pressure Washing Brings Your Patio Back to Life

Professional pressure washing removes mildew, algae, and grime from the surface of your concrete. Many homeowners are surprised by how much brighter and cleaner their patio looks after a thorough cleaning.

Pressure washing can:

• Remove dark mildew spots and green algae patches
• Clear grime that has settled into the concrete
• Reduce slippery buildup
• Restore a cleaner, more even appearance

It's also important to set realistic expectations. Pressure washing removes surface growth effectively, but some deep or long-set stains may lighten without disappearing completely. And if the conditions that caused mildew, like shade and moisture, stay the same, growth can return over time. Regular cleaning helps keep it under control.

Why the Right Approach Matters

Patios may be made of concrete, pavers, stone, or a combination. Each surface needs the right approach. Too much pressure can etch concrete, leave stripes, or wash sand out from between pavers. A professional team adjusts the approach to fit your patio for an even, safe clean.

How to Prevent Mildew From Coming Back

1. Let in more sunlight. Trim trees and shrubs that heavily shade your patio.
2. Adjust sprinklers so they don't spray your patio.
3. Improve drainage in low spots where water collects.
4. Extend downspouts so water drains away from your patio.
5. Keep gutters clean so overflow doesn't soak the area.
6. Sweep regularly to remove leaves and debris.
7. Move furniture and planters occasionally so the concrete underneath can dry.
8. Schedule regular pressure washing to keep growth from building up.

How Often Should You Pressure Wash Your Patio?

Most patios benefit from pressure washing once or twice a year. Shaded patios, pool decks, and areas prone to moisture may need cleaning more often to keep mildew and algae under control.

Great times to clean include:

• Spring, before outdoor season begins
• Early summer, before pool season and gatherings
• Fall, after leaves have dropped
• Before special events at your home

Complete Your Outdoor Refresh

A clean patio looks even better when the rest of your property matches. TruView Cleaning also offers:

• Pressure washing for driveways, walkways, pool decks, and other exterior surfaces
• Gutter cleaning to prevent overflow from soaking your patio
• Window cleaning for windows and glass doors facing your backyard, including the glass, frames, tracks, seals, and screens

What to Expect From TruView Cleaning

1. In-person walkthrough. We look over your patio and the areas with mildew or algae.
2. Clear service agreement and quote. You'll know exactly what's included and what to expect.
3. Scheduling. We schedule service at a time that works for you. Same-day service may be available depending on our schedule and your location.
4. Detailed service. Our team cleans carefully, paying attention to corners, edges, and shaded areas.

Every project is completed in-house by our own team.

Why DFW Homeowners Choose TruView Cleaning

We're local guys serving the DFW Metroplex, with a primary focus on Tarrant County. We bring a white-glove, detail-focused approach to every patio and outdoor space we clean.

Bring Your Patio Back to Life

Mildew on concrete can make your patio look old, dirty, and slippery. Professional pressure washing removes surface growth and brings back a cleaner, brighter outdoor space. With a few simple prevention steps and regular cleaning, your patio can stay ready for every season.

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