The Ultimate Guide to Pressure Washing Sandstone

Sandstone is a favorite material for both commercial and residential properties, known for its natural beauty, durability, and timeless appeal. From elegant patios to grand entryways, sandstone adds a touch of sophistication to any space. However, with time, this porous material tends to accumulate dirt, algae, mold, and other contaminants, potentially causing discoloration and damage.

Pressure washing is one of the most effective ways to restore sandstone’s original beauty, but it has to be done right. If you’re in the commercial cleaning industry or managing property maintenance, this guide will teach you everything you need to know about pressure washing sandstone effectively and safely.
 

Why Does Sandstone Require Special Care?

Before jumping into the pressure washing process, it’s crucial to understand sandstone's unique properties. Sandstone is a highly porous and relatively soft natural stone, which makes it susceptible to damage. Factors like high-pressure sprays, harsh chemicals, and poor cleaning techniques can lead to erosion, pitting, and disintegration of the stone.

This is why cleaning sandstone requires a balance of power and precision.
 

Common Sandstone Contaminants and Challenges

Effective sandstone cleaning starts with understanding the types of contaminants you’re dealing with. Below are the common problems commercial clients face when maintaining sandstone surfaces:

1. Moss and Algae

These green, black, or gray organisms thrive on sandstone’s porous surface, especially in shaded or damp areas. Over time, they can cause unsightly discoloration and slippery surfaces.

2. General Dirt and Traffic Marks

Sandstone walkways and patios, particularly in high-traffic commercial areas, accumulate dirt, grime, and scuff marks that obscure the stone’s natural color.

3. Mold and Mildew

Black spots of mold and mildew are common, especially in humid regions like Florida. If untreated, they can degrade sandstone over time.

4. Efflorescence

A white, powdery layer may sometimes appear due to the movement of salts through the stone. This issue is aesthetic and indicates that the stone is absorbing water, which can be harmful long-term.

These contaminants are not only unattractive but can also create safety hazards, such as slippery surfaces, and compromise the durability of the stone if not treated correctly.
 

How to Pressure Wash Sandstone Safely and Effectively

Step 1: Prepare the Surface

Before turning on your pressure washer, inspect the sandstone surface. Identify any weak points, existing cracks, or damaged areas that might require extra caution. Remove loose debris, leaves, and dirt manually or using a soft-bristle broom.

Step 2: Choose the Right Equipment

Choosing the right pressure washing equipment is critical to successfully cleaning sandstone without causing damage.

• Pressure Level: While sandstone can withstand pressure washing, it’s important to keep the pressure low, ideally between 500 to 1,500 PSI. Exceeding this can lead to erosion of the stone.
• Nozzle Type: Use a wide-angle nozzle (25 or 40 degrees) to distribute pressure evenly and reduce the force applied to the sandstone.
• Water Temperature: If grease or stubborn stains are present, consider using hot water. For general dirt and algae, cold water will usually suffice.

Step 3: Test on a Small Area

Before cleaning the whole surface, test the pressure washer on a small, inconspicuous area of the sandstone. This ensures the pressure and technique won’t cause damage and allows you to adjust settings if necessary.

Step 4: Pre-Treat with a Cleaning Solution

For optimal results, apply a sandstone-safe cleaning solution before pressure washing. Look for biodegradable or non-acidic cleansers labeled safe for natural stone. Combine with water according to the manufacturer’s instructions, and use a low-pressure sprayer to evenly coat the surface.

Allow the solution to sit for 5–10 minutes so it can loosen dirt, mold, and grime before rinsing. Avoid letting it dry on the surface.

Step 5: Pressure Wash with Care

• Begin with low pressure and gradually increase as needed.
• Hold the wand at a 45-degree angle and keep it at least 6–12 inches away from the sandstone surface to avoid direct force.
• Wash section by section, using even and consistent motions. Avoid focusing on a single spot for too long, which can cause pitting.
• For vertical surfaces, start at the top and work downward to prevent streaking.

Step 6: Rinse Thoroughly

Once you’ve cleaned the surface, rinse it thoroughly with plain water to remove any remaining detergent or loosened debris.

Step 7: Allow to Dry

After washing, sandstone requires adequate time to dry completely. Ensure that no pooling water remains, as trapped moisture can lead to long-term damage or the reappearance of mold and algae.
 

Best Practices for Long-Term Sandstone Maintenance

To keep sandstone in pristine condition year-round, here are some maintenance tips:

1. Seal the Stone

Apply a sandstone-appropriate sealant after washing to protect the surface from water, dirt, and stains. This step is particularly crucial for commercial properties with high foot traffic.

2. Clean Regularly

Incorporate regular cleaning into your maintenance routine to prevent dirt and grime buildup. A quarterly schedule is recommended for most commercial applications.

3. Trim Nearby Foliage

Shade and moisture encourage mold and algae growth, so keep trees and shrubs around sandstone surfaces trimmed back.

4. Promptly Address Stains

Remove spills and stains (e.g., oils, grease) as quickly as possible to avoid permanent discoloration.
 

Why Hire Professionals for Sandstone Pressure Washing?

While pressure washing sandstone might seem straightforward, it’s a job that demands expertise and precision. Professionals have the appropriate tools, techniques, and experience to ensure your sandstone surfaces are cleaned thoroughly without damage.

If you’re managing a commercial property, the last thing you want is to deal with costly repairs or replacements due to improper cleaning methods. Investing in professional pressure washing services ensures long-lasting results and preserves the beauty of your sandstone installations.
 

Want Pristine Sandstone? We’ve Got You Covered!

Sandstone is a valuable element of any commercial space, but maintaining its beauty and functionality requires proper cleaning and care. Before you risk damaging this delicate material, trust the experts.

If you need professional commercial pressure washing, contact Central Florida's Professional Commercial Cleaning Company today to get a quote. Our trained specialists will take care of your sandstone cleaning needs, leaving it looking as good as new!