Many homeowners and property managers turn to pressure washing for fast and visible results. But can this technique of force backfire? Can it harm concrete or brick instead of helping it? Surprisingly, yes.
The same power that removes years of built-up debris can also wreak havoc on your surfaces if used incorrectly. However, it cannot be stamped as dangerous just for that. We just have to be aware of how to use it correctly.
This article is just for that—To understand the gritty truth behind pressure cleaning. First things first.
Pressure Washing
Pressure washing operates by blasting water at high velocity. It’s aggressive and effective, but it’s not always safe. It’s especially not for every surface.
Concrete and brick may appear rugged, but beneath the surface lies vulnerability. These materials contain pores. If the pressure is too high or applied at the wrong angle, those tiny holes expand and cracks form. Over time, your solid walkway or brick wall starts to crumble.
The Nature of Concrete and Brick
Concrete is a strong surface. But even then, it remains porous that sucks in water. During winter, that water freezes, expands, and cracks appear.
Brick tells a similar story. Each unit consists of fired clay or shale. Strong, but also filled with microscopic pockets. Mortar joins the bricks. This paste-like glue is even more fragile. Blast it too hard and mortar chips away. Water seeps in, and decay begins.
So, pressure cleaning, when done wrong, speeds up that destruction.
Common Mistakes That Cause Damage
Now, let’s explore the traps many people fall into. The damage doesn’t come from the washer itself. It comes from misuse. Here are the usual suspects:
1. Using Too Much Pressure
Novices often assume that more pressure means better cleaning. False.
Cranking the washer to full blast can slice through concrete like butter. Over 3,000 PSI (pounds per square inch) is often too harsh. It eats away at surfaces instead of cleaning them. Use lower settings for delicate masonry.
2. Wrong Nozzle Choice
Nozzles direct water into specific patterns. Some spray wide fans, while others shoot narrow, concentrated jets. A 0-degree nozzle is the most intense. It should be avoided for brick and concrete. A 25- or 40-degree one spreads the pressure more gently.
3. Holding the Wand Too Close
Distance matters. Too close and the water cuts. A good rule? Stay 12 inches away from the surface and work methodically.
4. Spraying at Harsh Angles
Pointing the wand upwards pushes water into cracks. Over time, this can destabilise the structure. Always spray at a downward angle.
5. Cleaning Old/Damaged Surfaces
Age weakens everything. Older bricks or weather-beaten concrete already show signs of stress. Pressure washing them without care can strip off protective layers. As a result, erosion quickens and surfaces fall apart.
Signs of Damage After Pressure Washing
Wondering if you’ve gone too far? Look for these telltale clues:
- Etching:
Tiny lines or grooves on concrete (may look like scratches) can weaken the surface.
- Spalling:
Chunks of surface flaking off is called spalling. In other words, concrete starts shedding its top layer.
- Cracked Mortar:
Gaps between bricks, where the “glue” resides, disintegrate. Bricks loosen.
- Efflorescence:
White chalky residue on brick or concrete means water has intruded.
- Surface Pitting:
Small holes or depressions trap dirt and worsen over time.
Damage may not appear immediately. The warning signs often arrive late.
Best Practices for Safe Pressure Washing
You can still clean your property safely. Just follow the golden rules.
Use the Right PSI
Stick to 1,500–2,500 PSI for concrete. For brick, stay under 1,500 PSI. Less is more. Too much can erode even the toughest material.
Choose the Correct Nozzle
Opt for a 25-degree nozzle for general cleaning. Use a 40-degree nozzle for delicate surfaces. Avoid red tips (0-degree).
Test First
Try the washer on a small, hidden patch. Watch how the surface reacts. No change? Proceed. Flaking or chipping? Rethink your method.
Keep the Wand Moving
Never linger in one spot. Constant motion prevents deep etching. Move in long, smooth passes. Overlap slightly for even results.
Angle Wisely
Always aim the stream at a 45-degree angle. This reduces the impact force. Water glides over instead of drilling in.
Alternatives to Pressure Washing
There are other options for surface cleaning:
Soft Washing
This method uses low-pressure water mixed with biodegradable detergents.
- It kills algae and mould without brute force.
- Great for older bricks or fragile concrete.
Manual Scrubbing
Old-school but effective. Combine elbow grease with a stiff brush and masonry cleaner. Ideal for small areas or sensitive spaces.
Chemical Cleaning
Specialised solutions dissolve grime. But you must ensure that you use products designed for masonry.
- They target stains without abrasive force.
- Never mix chemicals without professional advice.
When to Call the Professionals
Pressure washing seems simple. Hose, nozzle, water—done. But damage repairs cost more than a professional cleaning session. Sometimes, hiring an expert is the right decision.
Call a pro if:
- Your concrete is cracked or stained with oil.
- Bricks are aged or crumbling.
- Mortar joints are loose or flaking.
- You’re unsure which equipment to use.
- The area is large or hard to access.
Professionals bring training and experience. They understand surface materials. They spot early signs of damage. They choose the right tools.
The Bottom Line
Done right, pressure washing restores beauty. Done wrong, it ruins structure. Concrete and brick may fool the eye with their toughness. But their pores and joints betray them.
Ensure two simple rules: Choose the right settings. Don’t fall into the trap of “higher equals better.”
If you need immediate cleaning assistance, reach out to ABS Cleaning. They aim gently and let your surfaces shine.
