Pressure Washing vs. Soft Washing Brick: Which Is Safer and Why?

Richard Reynolds • November 8, 2025

Brick homes are known for their durability, classic appearance, and long lifespan. But when brick becomes stained with dirt, algae, moss, or mildew, many homeowners ask the same question: Should brick be pressure washed, or is soft washing safer?

Understanding the difference between pressure washing vs. soft washing brick is critical. While both methods can clean exterior surfaces, using the wrong approach on brick can lead to costly and irreversible damage. In this article, we’ll break down how each method works, the risks involved, and why soft washing is often the safer choice for brick surfaces.

Understanding Brick as a Building Material

Before comparing cleaning methods, it’s important to understand how brick behaves.

Brick is a porous material, meaning it absorbs water. While fired brick itself is relatively strong, the mortar joints holding the brick together are much softer and more vulnerable to erosion. Older homes and historic brick structures are especially susceptible to damage from aggressive cleaning methods.

Common contaminants found on brick include:

Algae and moss
Mold and mildew
Efflorescence (white mineral deposits)
Pollution and organic staining

Removing these safely requires the right technique—not just more force.

What Is Pressure Washing?

Pressure washing uses high-pressure water, typically ranging from 1,500 to over 4,000 PSI, to blast dirt and grime from surfaces.

How Pressure Washing Works

Relies on mechanical force
Uses little to no cleaning solution
Immediate visual results
Commonly used on concrete, driveways, and heavy-duty surfaces

Risks of Pressure Washing Brick

While pressure washing may seem effective, it comes with serious risks when used on brick:

Mortar erosion – High PSI can wash out mortar joints, leading to structural weakness
Brick spalling – Water forced into brick pores can cause the brick face to flake or crack during freeze-thaw cycles
Moisture intrusion – Damaged brick absorbs more water, increasing mold and interior moisture issues
Shortened lifespan – Repeated pressure washing accelerates brick deterioration

According to the Brick Industry Association, improper cleaning methods are one of the leading causes of premature brick failure.

What Is Soft Washing?

Soft washing is a low-pressure cleaning method that uses specialized cleaning solutions to break down organic growth rather than blasting it away.

How Soft Washing Works

Uses low pressure (typically under 300 PSI)
Relies on biodegradable detergents
Kills algae, mold, and mildew at the root
Provides longer-lasting results

Soft washing treats the cause of staining instead of just removing the surface appearance.

Pressure Washing vs. Soft Washing Brick: Key Differences

Feature	Pressure Washing	Soft Washing
Water Pressure	High (1,500–4,000 PSI)	Low (<300 PSI)
Cleaning Method	Force-based	Chemical-based
Risk to Brick	High	Minimal
Mortar Safety	Often damaged	Preserved
Longevity of Results	Short-term	Long-term
Recommended for Brick?	Rarely	Yes

Why Soft Washing Is Safer for Brick

1. Protects Mortar Joints

Mortar is designed to be softer than brick so it can flex and absorb stress. High-pressure water can easily carve it away, leading to expensive tuckpointing or masonry repairs.

2. Prevents Brick Spalling

Spalling occurs when water enters brick pores and causes the surface to chip or peel. Soft washing avoids forcing water into the brick, reducing this risk dramatically.

3. Kills Organic Growth Completely

Pressure washing often leaves behind spores and roots. Soft washing kills mold, algae, and mildew at the microbial level, slowing regrowth.

The Environmental Protection Agency (EPA) notes that mold spores can survive surface cleaning if not properly treated.

4. Longer-Lasting Results

Because soft washing removes the organisms causing the stains, brick stays cleaner 2–4 times longer compared to pressure washing.

When Is Pressure Washing Brick Ever Appropriate?

There are limited cases where pressure washing brick may be acceptable:

Newer brick construction
Very low PSI settings
Wide fan-tip nozzles
Performed by trained professionals

Even then, many masonry experts recommend soft washing first, with pressure used only as a last resort.

The International Masonry Institute advises against aggressive pressure cleaning on most brick surfaces.

Common Brick Damage Caused by Improper Pressure Washing

Homeowners often don’t notice damage immediately. Signs can appear months later.

Warning Signs Include:

Crumbling or missing mortar
Flaking brick faces
White powdery residue (efflorescence)
Increased indoor humidity
Dark moisture stains after rain

Once brick damage occurs, cleaning costs can quickly turn into thousands in masonry repairs.

Soft Washing Brick: The Professional Process

A professional soft wash typically includes:

Surface inspection to identify brick type and condition
Pre-wetting to protect landscaping and prevent chemical absorption
Application of cleaning solution designed specifically for masonry
Dwell time to allow growth to break down naturally
Gentle rinse using low-pressure water

This method is endorsed by many masonry preservation organizations, especially for older and historic buildings.

DIY vs. Professional Brick Cleaning

DIY Risks

Using too much pressure
Incorrect chemical mixtures
No understanding of brick age or composition
Potential warranty or insurance issues

Professional Benefits

Correct PSI and cleaning agents
Knowledge of brick and mortar types
Liability protection
Longer-lasting, safer results

If you’re unsure, it’s always safer to consult a professional brick cleaning service.

Pressure Washing vs. Soft Washing Brick: Final Verdict

Soft washing is almost always the safer and more effective option for cleaning brick.

While pressure washing may appear faster, it carries significant risks that can permanently damage brick and mortar. Soft washing provides a deeper clean, protects your home’s structure, and delivers longer-lasting results—all without unnecessary force.