DOFF vs TORC vs soft washing: which facade cleaning method?
Most facade cleaning comes down to three methods, and using the wrong one is what scars masonry or voids a coating. Here is what DOFF, TORC and soft washing actually do, which surfaces and soiling each suits, and how to tell which your building needs before anyone gives you a price.
DOFF: superheated steam, low pressure
DOFF is a system that cleans with water heated up to around 150 degrees, delivered at low pressure. The heat does the work, not the force, so it lifts biological growth, algae, moss and general soiling without blasting the surface. Because the pressure is low and the output is essentially sterilising steam, it suits sound stone, brick and many heritage surfaces, and it kills spores so regrowth is slower.
It is the go to for organic soiling and light to moderate staining on masonry where you want to avoid surface damage. It is slower and more skilled than a pressure wash, which is part of why facade cleaning is priced per job.
TORC: a gentle swirling vortex
TORC cleans with a low pressure swirling vortex of water, air and a fine inert granulate. The swirl spreads the energy so it lifts carbon, paint and heavy atmospheric staining from robust stone and masonry without the harsh cutting of grit blasting. It is the method reached for when soiling has gone beyond what steam alone will shift, particularly decades of carbon on portland stone or paint on a listed frontage.
It is calibrated to the surface, with the media and pressure chosen for the substrate, and a test patch is normal before committing an elevation. Used correctly it is gentle; used wrongly it can still abrade, which is why it belongs in experienced hands.
Soft washing: low pressure and a biocide
Soft washing applies a biocide that kills algae, lichen and moss at the root, then rinses at low pressure. Rather than blasting growth off, it treats it so it dies and washes away, and a residual effect slows it coming back. It suits render, painted surfaces, panel and composite cladding and roofs, anywhere high pressure would force water behind the surface or strip the finish.
It is the right answer for the green and black organic staining that leaseholders complain about on render and cladding. Done to specification, it is gentle enough to protect coatings and warranties.
How to choose by substrate and soiling
The substrate sets the shortlist and the soiling narrows it. Render, cladding and painted surfaces point to soft washing. Sound stone and brick with organic growth point to DOFF. Stone or masonry with carbon, paint or heavy staining points to TORC, often after a steam pass. Many real elevations need a combination across one building, which is why a survey and a test patch matter more than a single favoured method.
The warning sign on any quote is a single aggressive method applied to everything, especially high pressure jetting or sandblasting on masonry or coated cladding. That is what drives water into the wall, strips the fired skin off brick, and voids cladding warranties. The right specialist matches the method to the surface, not the surface to their kit.
Frequently asked
What is the difference between DOFF and TORC?
DOFF cleans with superheated steam at low pressure and suits organic soiling and lighter staining on sound masonry without surface damage. TORC uses a low pressure swirling vortex with a fine inert media to lift carbon, paint and heavy staining from robust stone. DOFF is gentler; TORC handles tougher, baked in soiling.
Is soft washing better than pressure washing?
For render, cladding and painted surfaces, almost always. Soft washing kills algae and growth with a biocide and rinses at low pressure. It does not force water behind the surface or strip the finish the way high pressure jetting can. Pressure washing is rarely the right call on a building envelope.
Which facade cleaning method is safe for listed or heritage masonry?
Usually DOFF superheated steam for organic soiling, stepping up to a carefully calibrated TORC vortex for carbon or paint, always after a test patch. Sandblasting and high pressure are avoided on heritage masonry because they remove the surface and accelerate future soiling.
Will the wrong cleaning method damage my building?
Yes. High pressure and abrasive blasting strip the fired skin off brick, erode the face of stone, and can void cladding coating warranties. Matching the method to the substrate, with a test patch first, is what prevents trading dirt for permanent damage.
How do I know which method my building needs?
A survey of the substrate and the soiling decides it, often a combination across one elevation. Tell us the building and a vetted specialist identifies the surface, tests a small area, and prices the right method as a fixed job.
Not sure which method your facade needs?
Tell us about the building and you get a vetted specialist who covers your area. A surveyor comes back with a fixed price, usually within one working day.