Pressure Washing · Service

Concrete cleaning, matched to the slab you actually have

Garage floors, shop pads, steps and plain poured slabs — where oil, tyre scrub and years of dust live in the pores. Method and chemistry first; pressure second.

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In short

What is concrete cleaning?

Concrete cleaning is mechanical and chemical work on poured slabs — exterior pads, garage floors and utility areas — using a surface cleaner for even results and targeted pre-treatment for oil and rubber. Sound, unsealed concrete can take higher pressure than walls; sealed, stained, polished or already-spalling concrete cannot be treated the same way. The job succeeds when the crew names the finish and the stain chemistry before the machine starts.

Triggers

Signs you need concrete cleaning

The garage floor is black at the tyre paths and sticky at the drip line under the engine bay
A previous "clean" left zebra stripes that show every time the light hits the slab
You are about to seal, epoxy or coat the floor and contamination will ruin adhesion
White powdery bloom keeps returning after ordinary washing
Tyre marks and plasticizer staining from hot summer parking will not mop away
Outdoor plain concrete steps or a pad are green and dusty but not decorative stone
You can see wand stripes from a previous clean that look worse in raking light
A coating contractor has refused to start until the slab is properly prepped

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The job

How concrete cleaning actually works

Name the finish — bare, sealed, coated or polished

Bare grey concrete, acrylic sealer, epoxy, stain and polish all set different pressure and chemistry limits. A coat that is failing will lift in sheets if you clean it like raw slab. Naming the finish and stain class up front prevents the classic bright-halo-dark-centre oil failure.

Watch for: One price for "the concrete" with no finish identified. That is a guess, not a method. Ask for that risk to be named on the walkthrough, not after damage shows.
Separate dirt from chemistry stains

General soiling lifts with even mechanical cleaning. Oil, rust, tyre plasticizers and efflorescence need pre-treatment or a different product class before any rinse. Naming the finish and stain class up front prevents the classic bright-halo-dark-centre oil failure.

Watch for: More pressure sold as the answer to oil. Pressure removes paste around the stain and leaves a bright halo with a dark centre. Ask for that risk to be named on the walkthrough, not after damage shows.
Hot water and degreasers where grease lives

Garage and shop slabs often need heat and alkaline degreasers with dwell time. Cold water at high pressure is a poor substitute for dissolved grease. Naming the finish and stain class up front prevents the classic bright-halo-dark-centre oil failure.

Watch for: A residential wall-wash crew without hot water quoting a machine-shop floor as if it were a patio. Ask for that risk to be named on the walkthrough, not after damage shows.
Surface-clean in controlled passes

An enclosed spinning surface cleaner keeps distance and dwell consistent so the slab lightens uniformly. Edges and corners are detailed afterward. Naming the finish and stain class up front prevents the classic bright-halo-dark-centre oil failure.

Watch for: Open-wand work across the main field. Permanent striping is the signature failure of concrete cleaning done cheap. Ask for that risk to be named on the walkthrough, not after damage shows.
Rinse, dry path and coating readiness

Residue is rinsed out of pores and joints. If a coating follows, moisture and pH readiness are separate from "looks clean when wet." Naming the finish and stain class up front prevents the classic bright-halo-dark-centre oil failure.

Watch for: Same-day epoxy over a damp, high-pH slab. Bond failure shows up months later as peeling islands. Ask for that risk to be named on the walkthrough, not after damage shows.

Money

What does concrete cleaning cost?

Concrete cleaning is typically priced by area and condition, with garage oil work, hot water and heavy degreasing as adders. Coating prep is a different scope than a cosmetic wash. The Cost Guide covers how exterior and hard-surface cleaning quotes stack.

See the full concrete cleaning cost guide — by material, size and region →

Straight answer

When concrete cleaning is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

The slab is spalling, scaling or losing aggregate. Cleaning highlights failure; it does not reverse freeze damage or de-icer burn. Repair or resurfacing first.
You want polished or stained concrete restored to showroom. That is a flooring or concrete-finishing trade with grinders and densifiers — not a pressure-wash visit.
A failing sealer or epoxy is peeling. Blasting the rest off without a removal plan creates a patchwork. Plan strip-and-recoating as a system.
The "concrete" is actually asphalt. Bituminous surfaces softens and ravel under the wrong pressure, especially in heat.
Historic or soft masonry is in the same bid. Do not let garage-floor settings migrate onto brick or soft stone steps.
You only need outdoor driveway aesthetics. If the whole problem is the approach apron, the driveway-cleaning page is the tighter fit.
You want oil stains gone with a consumer electric washer in an afternoon. Deep oil is multi-step chemistry; miracles sold at tool-rental pressure settings usually etch the slab.

Straight answer

Can I do this myself?

Garage degreasing products and hot rinse water create slick floors and chemical splash risk. Wear eye protection and non-slip footwear, ventilate the space, and never use a zero-degree tip near bare skin or soft metal thresholds.

Reasonable to DIY

Sweeping and dry-absorbing fresh oil before it soaks deeper
Using a dedicated concrete degreaser on a small test patch per label instructions
Renting a surface cleaner attachment rather than freehanding a wand on the open slab

Call a licensed pro

Whole-garage black tyre lanes and years of drip staining
Any job that feeds a coating or epoxy system
Large exterior slabs where wand striping would be permanent
Interior spaces where wash water has nowhere compliant to go

Before you sign

What to check when hiring for concrete cleaning

Is this slab bare, sealed or coated — and how does that change your method?

Finish type is half the job definition. Get the answer in writing on the quote where it affects price or risk.
What is your plan for oil and tyre marks specifically?

If the answer is only "we turn up the pressure," keep shopping. Get the answer in writing on the quote where it affects price or risk.
Do you have hot water available for this garage?

Grease and cold water are a mismatch on most shop floors. Get the answer in writing on the quote where it affects price or risk.
Surface cleaner on the open field — yes or no?

Predicts striping better than any price comparison. Get the answer in writing on the quote where it affects price or risk.
If I am coating afterward, is this quoted as prep or as cosmetic clean?

Prep standards are stricter; scope should say so. Get the answer in writing on the quote where it affects price or risk.
Where does wastewater go from an interior garage?

Floor drains, yard and street each have different rules and neighbour impacts. Get the answer in writing on the quote where it affects price or risk.
What moisture or readiness standard applies if this is coating prep?

Cosmetic clean and coating prep are different deliverables with different failure modes. Get the answer in writing on the quote where it affects price or risk.

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Local pros

Concrete Cleaning near you

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Related work

Often done at the same time

Driveway Cleaning

Outdoor approach flatwork

Patio Cleaning

Entertaining slabs and pavers

Pool Deck Cleaning

Wet-area concrete and coping

Pressure Washing

When force is and is not appropriate

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FAQ

Concrete Cleaning — questions people ask

Still have a question? Talk to our team →

Will pressure washing remove oil from a garage floor?

Not by pressure alone. Oil sits in the pore structure. Degreasers, dwell time, agitation and often heat pull it out; rinsing then removes the suspended soil. Old, deep stains may lighten without disappearing — honest crews say that before they start. A good contractor will explain the trade-offs in plain language before you book the date.

How is concrete cleaning different from driveway cleaning?

Overlap is real on outdoor plain slabs. This page focuses on material behaviour — sealed and coated floors, interior garages, oil chemistry and coating prep — whereas driveway cleaning centres outdoor approach aesthetics, pavers and curb runoff. Many crews do both; the questions you ask should match the slab. A good contractor will explain the trade-offs in plain language before you book the date.

Can sealed concrete be pressure washed?

Sometimes gently, sometimes not. Fresh or sound sealer can water-spot or haze under aggressive settings; failing sealer can peel. The crew should test a corner and may switch to lower pressure and different chemistry rather than a driveway recipe. A good contractor will explain the trade-offs in plain language before you book the date.

Why did my last clean leave stripes?

Open-wand work at inconsistent distance and speed removes cement paste unevenly. Those lines are surface erosion, not dirt. A surface cleaner is the prevention; resurfacing is often the only cure once stripes exist. A good contractor will explain the trade-offs in plain language before you book the date.

Should I clean before epoxy?

Yes, and to a higher standard than "looks lighter." Contaminants and laitance kill adhesion. Ask the coating installer what prep they require and whether the cleaner and the coater are coordinating — two trades, one failure mode if they do not. A good contractor will explain the trade-offs in plain language before you book the date.

Does hot water always matter on garage floors?

Not always, but for years of oil and rubber it often does more than cold water at high pressure. Heat helps dissolve grease so chemistry and agitation can lift it from the pores. A residential wall-wash crew without hot water may still lighten dust and light film; they will struggle on black tyre lanes and drip lines. Match the toolkit to the stain class. A good contractor will explain the trade-offs in plain language before you book the date.