Your interlock pavers look stunning when they’re first installed, but over time, stains happen. Oil drips from vehicles, rust bleeds from metal furniture, white haze appears mysteriously, and organic matter leaves dark marks. The good news? Most interlock stains are removable with the right approach.

This comprehensive guide covers everything you need to know about cleaning different types of interlock stains, from DIY solutions to when you should call in professionals. Whether you’re dealing with stubborn oil stains on your driveway or mysterious white deposits on your patio, we’ve got you covered.

Understanding Different Types of Interlock Stains

Not all stains are created equal. The key to effective cleaning is identifying what type of stain you’re dealing with, because each requires a different approach and cleaning solution.

Oil and Grease Stains

These are among the most common stains on interlock driveways. Motor oil, transmission fluid, and grease create dark, spreading stains that penetrate deep into the paver surface. Fresh oil stains are easier to remove than old, set-in stains that have had months or years to bond with the paver material.

Oil stains appear as dark brown or black marks, often with an irregular spreading pattern. They may feel slightly slick to the touch even after the surface oil has evaporated.

Rust Stains

Rust stains appear as orange, brown, or reddish marks on your pavers. They typically come from metal furniture, planters, garden tools, or even from iron content within the pavers themselves bleeding to the surface when exposed to water and oxygen.

These stains can be particularly stubborn because rust is an oxidation process that chemically bonds with the paver surface. Standard cleaning won’t touch them, you need specific rust removers.

Efflorescence (White Haze)

That mysterious white, powdery substance appearing on your pavers is called efflorescence. It’s not actually a stain but rather salt deposits that migrate from within the concrete to the surface as moisture evaporates. This is extremely common on new installations and after wet seasons.

Efflorescence looks like white powder, chalky residue, or crystalline deposits. It’s more noticeable on darker colored pavers. While it’s harmless, it’s unsightly and many homeowners want it removed.

Organic Stains

Leaves, mulch, wood, grass clippings, and other organic materials can leave dark brown or black stains on pavers. These stains are caused by tannins in the organic matter, particularly noticeable under planters, beneath leaf piles, or where organic debris accumulates.

Moss, algae, and mildew also fall into this category, creating green, black, or dark staining along with a slippery biofilm on the surface.

DIY Cleaning Methods That Actually Work

Many interlock stains can be tackled with DIY methods using readily available products. Here’s what works for each stain type.

Cleaning Oil and Grease Stains

For Fresh Oil Stains:

Immediately cover the stain with an absorbent material like cat litter, cornstarch, or baking soda
Let it sit for 24-48 hours to draw out as much oil as possible
Sweep up the absorbent material
Apply dish soap (Dawn works exceptionally well) directly to the stain
Scrub with a stiff brush
Rinse with hot water
Repeat as necessary

For Set-In Oil Stains:

Use a commercial degreaser designed for concrete (TSP – trisodium phosphate – is highly effective)
Apply the degreaser according to manufacturer instructions
Let it dwell for the recommended time (usually 10-30 minutes)
Scrub vigorously with a stiff-bristled brush
Pressure wash or rinse thoroughly with hot water
Multiple applications may be necessary for old stains

Some homeowners swear by poultice methods: mix an absorbent powder with a solvent to create a paste, apply it to the stain, cover with plastic, and let it sit for 24-48 hours before removing.

Removing Rust Stains

Rust requires an acidic cleaner to break down the iron oxide bonds:

Use a commercial rust remover specifically designed for concrete (look for products containing oxalic acid or phosphoric acid)
Apply the rust remover directly to the stained area
Let it dwell according to product instructions (typically 5-15 minutes)
You’ll often see the rust stain changing color as it reacts
Scrub with a brush
Rinse thoroughly with water
Neutralize if required by the product

Natural DIY Option: Make a paste of lemon juice and salt, apply to the rust stain, let it sit in sunlight for a few hours, then scrub and rinse. This works for light rust stains but isn’t as effective as commercial products for heavy staining.

Important: Never use muriatic acid or harsh acidic cleaners on interlock pavers. These can etch the surface, discolor the pavers, and damage the integrity of the material.

Eliminating Efflorescence

Efflorescence is actually the easiest “stain” to remove:

Start with dry brushing using a stiff-bristled brush to remove loose deposits
Use an efflorescence cleaner (these are mild acidic solutions specifically formulated for salt deposits)
Apply the cleaner, let it dwell briefly, then rinse thoroughly
For light efflorescence, pressure washing alone often does the trick
White vinegar diluted with water (1:1 ratio) can work for mild cases

Prevention Tip: Efflorescence often returns until the pavers have fully cured and stopped releasing salts. This can take 1-2 years on new installations. Sealing your interlock after it’s fully cured helps prevent future efflorescence by creating a barrier that prevents moisture from penetrating and drawing out more salts.

Treating Organic Stains and Growth

Organic stains respond well to oxidizing cleaners:

Mix oxygen bleach (sodium percarbonate) with water according to package directions
Apply to the stained areas
Let it sit for 15-30 minutes
Scrub with a brush
Rinse thoroughly

For moss, algae, and mildew:

Use a solution of water and oxygen bleach, or a commercial algae/moss remover
Apply to affected areas
Allow adequate dwell time for the product to kill the growth
Scrub away dead growth with a stiff brush
Rinse clean
Consider improving drainage and sunlight exposure to prevent regrowth

What to Avoid: Never use chlorine bleach on colored pavers as it can cause discoloration and fading. Stick with oxygen bleach, which is safer for colored surfaces.

When to Call Professional Cleaners

While many stains can be DIY projects, there are situations where professional interlock cleaning is worth the investment:

You Should Call Professionals When:

Large Areas Need Cleaning: Cleaning an entire driveway is time-consuming and physically demanding. Professionals have commercial-grade equipment that makes the job faster and more effective.
Stains Won’t Budge: If you’ve tried DIY methods and the stains persist, professionals have access to stronger, specialized products and the experience to use them safely.
You’re Preparing for Sealing: Before sealing interlock, the surface must be completely clean. Professional cleaning ensures no residue or contaminants that could prevent proper sealer adhesion.
You Need Restoration: Severely stained, discolored, or deteriorating pavers may need more than just cleaning. Professionals can assess whether you need interlock repair or replacement in addition to cleaning.
You Want Preventive Maintenance: Annual or bi-annual professional cleaning keeps pavers looking great and extends their lifespan by preventing buildup of damaging substances.

What Professional Cleaning Includes

Professional interlock cleaning typically involves:

Pre-treatment of stains with appropriate specialty cleaners
Hot water pressure washing at appropriate PSI (too much pressure can damage pavers)
Re-sanding of joints after cleaning
Optional sealing service to protect the investment
Proper disposal of wash water and debris

Professionals also know the correct pressure settings and techniques to avoid damaging pavers, displacing joint sand, or creating “wand marks” from inconsistent pressure washing.

Product Recommendations and What to Avoid

Products and Methods to Avoid

Never Use:

Muriatic Acid or Hydrochloric Acid: Too harsh, can etch and discolor pavers permanently
Wire Brushes on Delicate Pavers: Can scratch and damage the surface finish
Excessive Pressure Washing: Over 2000 PSI can damage pavers and displace joint sand
Chlorine Bleach on Colored Pavers: Causes fading and discoloration
Sealers Over Dirty Pavers: Sealing traps stains and prevents proper adhesion
Metal Shovels for Snow Removal: Not a cleaning product, but worth noting – metal shovels scrape and damage paver surfaces, creating areas where stains can penetrate more easily

Preventing Future Stains

The best stain removal strategy is prevention:

Seal Your Pavers: Professional sealing creates a protective barrier that makes stains easier to remove and prevents deep penetration. Learn more about whether you should seal your interlock.
Clean Spills Immediately: Fresh stains are exponentially easier to remove than set-in stains
Use Furniture Pads: Place plastic or rubber pads under metal furniture to prevent rust staining
Regular Maintenance: Sweep weekly, rinse monthly, and deep clean annually
Address Drainage Issues: Standing water accelerates efflorescence and promotes organic growth
Park Leaking Vehicles Elsewhere: If a vehicle is leaking fluids, park it on asphalt or concrete until repairs are made

Your Interlock Cleaning Action Plan

Here’s your step-by-step approach to interlock cleaning:

Identify the Stain Type: Determine what you’re dealing with (oil, rust, efflorescence, or organic)
Start Gentle: Try the mildest effective method first
Test First: Always test cleaning products on an inconspicuous area to ensure they don’t cause discoloration
Follow Product Instructions: Respect dwell times, dilution ratios, and safety precautions
Rinse Thoroughly: Remove all cleaning product residue
Assess Results: If DIY methods don’t work after 2-3 attempts, consider professional help
Protect Your Investment: After cleaning, consider sealing to prevent future staining

Professional Interlock Cleaning in Ottawa

Your interlock represents a significant investment in your property’s beauty and value. While many stains can be removed with DIY methods, sometimes you need professional expertise and equipment to restore your pavers to their original glory.

At Interlock Experts, we provide comprehensive interlock cleaning services using professional-grade equipment and specialized cleaning products. We know exactly which products work on which stains, the correct pressure washing techniques to avoid damage, and how to properly prepare your interlock for sealing.

Whether you’re dealing with stubborn oil stains on your driveway, rust marks on your patio, or years of accumulated grime, we can help. Our cleaning services can be combined with sealing to provide maximum protection, or paired with repair services if your pavers need restoration beyond cleaning.

Ready to restore your interlock to like-new condition? Contact Interlock Experts today for a free quote on professional interlock cleaning. We serve Ottawa, Kanata, Barrhaven, and all surrounding areas with expert cleaning, sealing, and maintenance services.

Call us or fill out our online form to schedule your consultation. Let us show you what your pavers can look like when they’re properly cleaned and maintained.

Interlock Cleaning Guide: Stains, Rust, Oil, Efflorescence (What Works)