Brick Cleaning: DOFF vs. Pressure Washing for Heritage and Modern Sites

When brickwork starts to look tired, darkened by carbon staining, green with algae, or patchy from pollution, most facilities teams consider two routes: a DOFF cleaning system or pressure washing services. Both have their place, but choosing the wrong method can etch brick faces, drive water into the fabric, or strip protective coatings. For heritage façades and modern commercial sites alike, understanding the difference is critical.

At Exterius, our DOFF cleaning specialists deliver sensitive restoration on listed buildings and contemporary developments across the UK – from DOFF cleaning Birmingham and the West Midlands to DOFF steam cleaning London and major cities nationwide. This guide explains when to specify DOFF and when a controlled form of pressure washing (often called building pressure washing or commercial pressure washing services) is the better fit.

What Is DOFF Steam Cleaning?

The DOFF cleaning system is a specialist tool that cleans using superheated steam (up to ~150°C) at very low pressure and low flow. That combination lifts soiling, algae and certain paints without driving water into the substrate or abrading delicate surfaces.

Why specifiers choose DOFF for brick:

Low pressure, high temperature: Dislodges pollutants and organic growth while protecting the brick face and mortar arrises.
Minimal water: Surfaces dry quickly, reducing the risk of trapped moisture, efflorescence, or freeze–thaw damage.
Less chemical reliance: Many tasks can be completed with water only, supporting sustainability goals.
Heritage safe: Favoured by conservators for sensitive substrates and historic sites.

If you’re searching for a DOFF cleaner, DOFF steam cleaner, DOFF machine, or DOFF cleaning UK generally, you’re looking for approved operatives who can tune temperature, nozzle and flow precisely for your brick and soil type.

What Is Building Pressure Washing?

“Pressure washing” covers a spectrum – from gentle, fan-spray rinses to aggressive jetting. On robust, modern brickwork (and ancillary surfaces like hardstandings), commercial pressure washing services can be efficient and cost-effective when delivered by trained teams with strict pressure, angle, and standoff controls, plus runoff management.

When controlled pressure washing may suit brick:

Modern, hard-fired bricks and robust mortars without heritage constraints.
Heavier inorganic soiling on plinths or lower courses, where abrasion risk is lower and controlled pressure can be safe.
Pre-paint prep on non-heritage substrates where a mechanical key is acceptable (often combined with other methods).

Caution: Uncontrolled jetting can erode faces, open mortar joints, and force water behind the skin, especially on older clay bricks or weathered façades. If in doubt, specify DOFF or test first.

DOFF vs. Pressure Washing: Quick Comparison

DOFF steam cleaning

Best for: Heritage façades, soft/porous brick, lime mortars, carbon staining, algae/moss, delicate details.
Pros: Low pressure, low water, gentle on fabric, rapid drying, minimal chemicals.
Considerations: Slightly slower lineal progress on heavy grime; requires DOFF cleaning specialists.

Controlled pressure washing

Best for: Modern brickwork, robust mortars, external hard surfaces, preparatory cleans before coatings in non-heritage contexts.
Pros: Faster on certain soils, cost-effective over large robust areas.
Considerations: Risk of damage if misused; needs strict pressure/flow/nozzle control and runoff capture.

Heritage Sites: Why DOFF Leads

Historic brick varies widely in porosity and strength. Lime mortars and hand-made bricks are particularly vulnerable to high-pressure jetting. DOFF’s low-pressure steam loosens contaminants and bio-growth without shocking the surface or flooding cavities.

Typical heritage applications:

Carbon staining on urban elevations
Algae and moss in shaded courses and copings
Graffiti removal on brick without harsh chemicals or scour
Fire and smoke residues, lifting soot without smearing

For conservation officers, the case is clear: specify DOFF first, pressure washing only by exception following trials and method statements.

Modern Commercial Brickwork: Which Way to Go?

Not all contemporary brick is equal. Many modern façades layer brick slips, insulation, membranes, sealants and movement joints – each with moisture pathways to respect. In retail parks, logistics hubs and campuses, we often mix methods:

Primary façade cleaning: DOFF for elevations, returns, signage interfaces and soffits.
Robust zones: Controlled pressure washing on plinths, boundary walls and ramps.
Detailing: Soft rinses around sealants, vents, cameras and interfaces to prevent ingress.

This hybrid approach protects the building envelope while delivering pace on suitable areas.

Method Selection: How We Decide

Every Exterius brick clean starts with a site survey and small-area test panels. We assess:

Brick type & condition: Hand-made vs. machine-made; spalling; salt activity.
Mortar & joints: Lime vs. cement; pointing soundness; joint recession.
Soiling profile: Carbon, bio-growth, traffic film, salts, paint, smoke.
Exposure & moisture: Shaded elevations, parapet defects, prior water ingress.
Constraints: Public footfall, adjacent glazing, sensitive landscaping, drainage.

We then specify a DOFF-first approach for risk-bearing zones, with controlled pressure washing only where fabric and risk profile allow.

Environmental & Compliance Considerations

Whether DOFF or pressure, compliant delivery matters:

Runoff control: Capture, filtration and disposal to suit local regs.
Water & chemical minimisation: DOFF often allows water-only cleans; when detergents are necessary, we use approved, biodegradable products.
Noise & scheduling: Early-start or out-of-hours programmes for retail, education and healthcare sites.
Documentation: Full RAMS, access plans (MEWPs/rope), and after-care guidance for FM teams.

Risks to Avoid (and How We Prevent Them)

Face loss & etching: Caused by aggressive jetting. We avoid with DOFF or controlled settings and test panels.
Water ingress & efflorescence: Low-flow DOFF and correct sequencing limit moisture loading.
Streaking/patchiness: Section planning, consistent passes, and controlled drying reduce differential appearance.
Residues & re-soiling: Where detergents are used, we neutralise and rinse; DOFF’s high temperature often negates detergent entirely.

When to Call DOFF Cleaning Specialists

Heritage or listed façades, lime mortars, hand-made bricks
Mixed substrates (brick/stone/terra cotta) on one elevation
Evidence of previous jet-wash damage or spalling
Persistent carbon staining, smoke residues or layered bio-growth
Sensitive city-centre sites with strict runoff rules

If you’re scoping DOFF cleaning UK-wide or comparing options in the Midlands or the capital, our survey will confirm the safest, most effective route.

Book Your Brick Cleaning Survey

Protect your brickwork, whether it’s a listed elevation or a modern commercial façade. Speak to Exterius about DOFF steam cleaning vs commercial pressure washing services, and we’ll design a method that restores appearance without risking the fabric.

FAQs

Is DOFF steam cleaning always better than pressure washing for brick?
Not always. For heritage brick or fragile substrates, the DOFF system is generally safer. On robust, modern brickwork, commercial pressure washing services can be suitable – provided pressures, nozzles and standoff distances are tightly controlled. We often combine both.

Will DOFF remove paint or heavy carbon from brick?
DOFF can lift many paints and carbon films on brick without abrasion. Very stubborn coatings may require a targeted poultice or combined methodology. That’s why engaging DOFF cleaning specialists for testing is key.

How often should brick façades be cleaned?
Urban sites (e.g., DOFF cleaning Birmingham arterial routes or DOFF steam cleaning London zones) often benefit from an annual or biennial programme. Lower-pollution sites may extend intervals to 24–36 months. Your exposure, brick type and brand standards will guide the schedule.

Is DOFF cleaning environmentally friendly?
Yes, DOFF uses minimal water and often no chemicals. Where detergents are necessary (e.g., heavy traffic film), we specify biodegradable products and manage runoff responsibly.

Can pressure washing damage brick?
Yes, if misapplied. High pressure can erode faces and drive water through joints. Our building pressure washing is tightly controlled and frequently paired with DOFF to protect the envelope.

Do you operate nationwide?
We provide DOFF cleaning UK-wide, including Birmingham, the West Midlands, London, and major cities. We also deliver integrated pressure washing services for robust applications.