As a Des Moines concrete contractor with over 10 years of experience, I often get calls from frustrated homeowners needing help removing stubborn stains from their cement patios. Over my years in business, I’ve helped eliminate all kinds of eyesores like leaf tannins, oil spills, grease drippings, mold, mildew growth, and rust discoloration.
First, I’ll explain the most common patio stains I encounter in my contracting business. Then I’ll provide various do-it-yourself solutions or professional cleaning options to effectively eliminate them.
Why Concrete Patios So Easily Stain
Concrete is porous – Unlike materials like brick or tile, the cement paste used to bind together the sand and gravel in concrete is permeable, allowing spills from food, drinks, grill smoke and other household items to soak into the slab.
Midwest weather is harsh – The many cycles of sun, rain, snow and ice yearly expose concrete to more extremes, causing cracks and other deterioration where stains can form.
The Most Common Stains Plaguing Des Moines Area Patios
In my experience, here are the 5 patio stains Des Moines homeowners encounter repeatedly:
Leaf Tannins
Autumn brings vibrant fall foliage, but also headaches from fallen leaves littering patios. As leaves decompose, they can leave behind brown tannin splotches on concrete that can be difficult to remove. These ugly stains often blend together forming large discolored areas.
Oil and Grease Stains
Oily vehicle drips from parked cars coupled with heavy grease drippings from grills create dark blotchy stains. These stains often have defined edges around them depending on spill shape. Oil and grease can be among the trickiest stains to eliminate since they penetrate the concrete so deeply in many cases.
Mold and Mildew Stains
Damp, shaded areas of patios frequently fall victim to mold and mildew growth leaving dark patches and greenish black stains. Mildew thrives in areas that don’t dry quickly from rain or irrigation splash, especially under patio overhangs or dense landscaping.
Food and Drink Stains
It’s not uncommon for food and drink spills to permanently stain exterior concrete surfaces. Wine, greasy food drips, coffee spills, or sugary sodas can all embed into patio concrete resulting in lingering ghost stains.
Rust Stains
Metal furniture, tools like shovels or rakes, or decorative items left out exposed to moisture results in unsightly rust stains on patios. especially if the metal rests directly on the concrete over long periods. Rust leaches iron oxide residues into concrete creating reddish brown discoloration.
Prevent Future Patio Staining
An ounce of prevention is worth a pound of cure when it comes to concrete stains. It’s much easier to stop stains from developing in the first place compared to removing them after the fact. Here are 3 key tips to minimize stains:
Apply Concrete Sealer
Concrete sealers provide a protective barrier making spills bead up rather than soak in. However, sealers slowly wear away over 1-2 years. So you must reapply sealer regularly to maintain effectiveness. Solvent acrylics work well for patios. Topical film-forming sealers last the longest.
Promptly Wipe Any Spills
Don’t give spills a chance to soak in! Immediately soak up wine drips, blot sauce splatters, or scrape up food fallen through the grill grates. The quicker you act, the less likely spills can permanently stain.
Use Outdoor Floor Mats
Placing machine washable floor mats underneath patio tables and grills catches incidental spills and greasy messes before the patio sustains damage. Or consider interlocking outdoor patio tile – its surface resists staining compared to porous concrete.
Removing Stubborn Leaf Tannin Stains
Cause: Tannins from fallen foliage breakdown on concrete creating unsightly brownish and blackish splotches. Leaves sitting damp on patios worsen staining. The marks spread out the longer leaves remain on the slab.
Solutions:
The best prevention is blowing or sweeping frequently during fall to prevent leaves from piling up. But once stains set in, treatments include:
DIY Stain Cleaner
This oxygen bleach mixture can lift leaf tannins without dangerously high pH levels:
- Supplies – 1 cup powdered oxygen bleach cleaner, bucket, hot water, stiff deck scrub brush
- Mix 2 tbsp oxygen bleach powder with 1 gallon hot water
- Wet down nearby plants and grass to protect from splash exposure
- Apply bleach solution over stain area 1-2 sq ft at a time
- Let solution sit briefly before scrubbing vigorously with a stiff deck scrub brush
- Rinse thoroughly, repeat if needed for tougher sections
Professional Concrete Cleaning Service
For widespread tannin staining or sets-in tannins, I recommend hiring a full-service concrete cleaning company. Professionals have commercial walk-behind buffer machines to clean patios thoroughly. Rotary surface cleaners deeply clean while containing splash. And they can apply tannin neutralizers.
Expect costs around $200-300 for a basic single patio deep clean. Price varies based on staining severity, patio size, special chemical treatments needed, and more. But investing in professional cleaning now restores patio appearance for years before restaining recurs.
Eliminating Oil and Grease Stains
Cause: Parked car leaks create oily stains. Grills splatter grease on nearby concrete. Engine repairs or tune-ups also often stain driveways. Vehicle fluids and cooking grease share a stubborn nature when it comes to concrete staining.
Solutions:
DIY Cleaning Options for Oil & Grease
Dish soap makes a surprisingly handy concrete degreaser. For oil stains, try scrubbing with warm, soapy water using a firm push broom to provide abrasion. Rinse thoroughly afterward, let fully dry, checking if stains dissipate overnight before reapplying.
Baking soda mixed with just enough water to form a paste also absorbs some oil and grease when scrubbed into stains. Cover the paste completely with plastic wrap secured by tape. Let sit for 24 hours before scrubbing away the dried paste.
For tough or older oil and grease stains, use a commercial concrete degreaser from the hardware store following label directions. Apply using a deck brush and be patient – deep set grease stains may require repeat applications and scrubbing over weeks. If this was helpful, find solutions for other driveways stain here.
Professional Concrete Cleaner Solution
In tricky instances of concrete pores clogged with thick grease or leaks saturating a slab, I recommend hiring a professional concrete cleaning service. Commercial cleaners at certain higher hazardous pH concentrations combined with professional equipment can remove the toughest oil and grease stains regular DIY efforts cannot conquer.
Professionals also have access to advanced techniques like concrete grinding. This abrades stains away from the topmost concrete layer. Grinding does gradually thin the slab over successive cleanings. So weigh grinding’s stain removal power against slowly thinning concrete.
Typical pricing is around $400+ for intensive professional degreasing and concrete grinding. Price varies based on severity, size of affected areas, extra necessary treatments, and more.
Taking Out Mold and Mildew Stains
Cause: Microscopic mold and mildew organisms thrive on damp shaded patios, reproducing via spores. Common patio environments especially prone to heavy mold/mildew growth include:
- Under foliage canopy drip lines where irrigation rain or dew lingers
- Beneath patio covers trapping humidity with poor airflow
- Near downspouts dumping excessive roof runoff onto patios
- Low areas where water pools due to improper drainage
Left untreated over years, mold and mildew blooms destroy the integrity of cement surfaces through organic acids, expanding cracks and deterioration.
Solutions:
Bleach Solution
This stronger oxidizing DIY cleaner tackles both mold and mildew stains:
- Mix 3⁄4 cups bleach + 1 gallon water
- Wet/protect nearby plants
- Apply solution wearing gloves
- Let sit briefly before scrubbing then rinse thoroughly
However, higher concentrations of chlorine bleach corrode concrete and nearby metals over recurring applications.
Vinegar Remedy
For a non-toxic alternative, undiluted white vinegar kills mold and also helps concrete resist future growth. Spray generously, let penetrate 10+ minutes before scrubbing vigorously with a stiff deck brush. Vinegar’s acidity avoids concrete pitting risks bleach presents but requires more muscle power scrubbing.
Professional Mold Treatment
For severe infestations, hire a professional certified mold remediation specialist. Commercial mold and mildew chemicals more thoroughly and permanently eradicate growths. Trained pros also ensure complete fungal root removal. And they take safety precautions managing harsh chemicals.
Expect to invest $500+ for pro mold cleaning. Service pricing depends on affected area size, growth density, necessary containment construction, the number of chemical applications involved, plus protective gear and disposal fees.
Removing Food and Drink Stains
Cause: Sugary drinks, wine, condiments, greasy sauces, grill messes embed into exterior concrete dining and patio surfaces over time, leaving behind “ghost stains“.
Solutions:
DIY Cleaners
Dish soap mixed with warm water makes a handy first line of attack scrubbing many food/drink stains out of textured concrete.
Baking soda and hydrogen peroxide pastes also work well. Mix 4 tbsp baking soda + just enough 3% household hydrogen peroxide to form a thick peanut butter-like paste. Apply paste 1⁄4-1⁄2 inch thick over stain. Allow to bubble 5+ minutes before scrubbing vigorously with a stiff deck brush to lift stains. Rinse clean.
Oxygen bleach-based cleaners also target organic food stains. Follow label mixing directions based on surface area, applying with a deck brush and scrubbing repeatedly as needed.
Professional Stain Removal
Extensive ghost staining or single large stains sometimes necessitate concrete cleaning pros. Commercial-grade alkaline stain removers coupled with professional walk-behind floor buffers provide extra stain lifting power. Multiple applications may still be needed against stubborn staining.
In worst cases, stained upper concrete may need resurfacing. This involves grinding away thin stained layers followed by installing a fresh concrete topping coat. Resurfacing costs $6-8 per square foot but leaves a like-new concrete surface.
Eliminating Rust Marks
Cause: Metal rust formation requires moisture and oxygen. Outdoor furniture, tools, or decor exposed to regular rain, dew, or ground contact moisture corrode. Rust then leaches iron particles into porous concrete leaving reddish brown discoloration even after removing metal items.
Solutions:
Vinegar application
Spraying undiluted white vinegar on new rust stains delays further corrosion. Vinegar creates a thin protective layer, buying time for traditional rust removal. Re-apply every few days as needed. Vinegar suits light stains covering small areas.
Commercial Rust Removers
Seeking serious rust stain removal strength? Turn to commercial cleaners like Whink Rust Stain Remover or Reilly’s Rust Stain Remover instead containing powerful oxalic or phosphoric acids.
Follow manufacturer label safety precautions wearing long sleeves, gloves and eye protection against dangerous acid contact during application and scrubbing. Thoroughly rinse treated areas avoiding any runoff contacting lawn or plants. Harsh acids kill vegetation.
Professional Rust Neutralizing
Extensive rust staining sometimes necessitates concrete professionals. Contractors have access to advanced rust neutralizers converting staining iron oxides into clear compounds not visible to the eye. This avoids the gradual concrete thinning risks of repeated acid washes. And neutralizing prevents future recurrence in the same spot.
Pricing averages around $300+ for a single average size patio rust removal job. Contractors assess unique variables like density, coloring consistency and precise chemical reaction requirements on each unique job.
Signs Calling a Concrete Professional Makes Sense
DIY cleaner trials aim to avoid concrete cleaning service costs when tackling patio stains. But realizing limitations on chemical strengths, buffering equipment, and technique experience makes identifying when professional intervention clearly is the wise path forward important.
Signs a concrete cleaning pro probably is needed include:
Repeated DIY Attempts Failed
Frustration mounts trying homemade mixture after mixture without success. Don’t hesitate calling in the pros before completely destroying patio slab integrity from over-scrubbing or toxic chemical burns!
Staining Too Extensive
Cleaning products diluted for safety treating limited areas often can’t match commercial-grade strength fighting widespread staining.
Restoring Patio Quickly is Necessary
DIY cleaning methods rely on applications over hours or days. Professionals economically remove stains rapidly using concentrated chemicals, industrial machines and experienced techniques.
Handling Harsh Chemicals Raises Concerns
Worries about managing caustic rust removers or noxious mildew chemicals makes hiring concrete cleaning experts is the smartest solution. They safely apply solutions wearing proper protective equipment.
Don’t let past difficulties removing patio concrete stains deter summoning staining removal authorities before hosting summer parties or selling your home. Contractors economically restore stained cement to impress guests and boost home resale appeal.
Final Takeaways
I hope this stain removal guidance provides clarity on elegantly restoring the natural gray luster cherished in backyard concrete without breaking budgets.
The key is attempting immediate DIY cleaning when stains recently develop, steadily trying more intensive options before extensive staining accumulates forcing professional intervention. Caught early, many stains dissolve following fundamental cleaning steps using common household ingredients.
Yet when stains persist despite diligent scrubbing and rinsing using DIY methods, don’t hesitate calling concrete professionals. Their commercial-grade chemicals, walk-behind equipment, and application experience restore hopeless appearing staining cases other patio owners abandoned to eyesores.