Poultice, soft-brush, and low-pressure hand cleaning — the methods that predate DOFF and TORC, and still the right choice for localised staining, the most fragile surfaces, and anywhere mechanical or thermal intervention isn't appropriate.
This is the gentlest tier of cleaning we offer, and the one with the longest history. Poultice cleaning applies an absorbent or mildly chemical paste directly to a stained area, left to draw the stain out of the stone or brick as it dries, then removed and repeated if needed. Soft-brush and low-pressure hand cleaning uses nothing but water, natural bristle brushes, and patience — no steam, no aggregate, no mechanical action beyond a hand-held brush.
Where DOFF and TORC are our default methods for general atmospheric soiling across most London stone and brick, traditional cleaning is what we specify when the situation calls for something gentler still: a small area of localised staining, a surface too fragile or friable for any thermal or mechanical method, or a listed building context where the conservation officer has specified the least interventive method available.
Poultice is our first choice for localised staining that general cleaning won't address — iron rust bleeding from fixings, oil or grease contamination, mineral salts migrating to the surface, and organic staining from plant growth or bird activity. Because the poultice works by drawing the staining agent out through absorption rather than by any abrasive or thermal action, it's inherently low-risk on delicate surfaces. We use it regularly on Bath stone and other porous, softer materials where TORC's aggregate or DOFF's dwell time carries more risk than the soiling justifies.
A poultice application typically needs to remain in place for several hours to a few days depending on the stain and the poultice type, and more than one application is often needed for established staining. This is slower work than steam or vortex cleaning, and we account for that in the programme.
Soft-brush hand cleaning with water is appropriate where even DOFF's low-pressure steam carries more risk than the soiling justifies — the most friable and decayed stone surfaces, delicate carved detail in poor condition, or anywhere a conservation officer has specified the minimum-intervention method as a condition of consent. It is slow, labour-intensive work, and it removes less soiling than DOFF or TORC in the same time. We specify it when the priority is preserving what remains of the surface, not achieving the cleanest possible result.
DOFF and TORC are both, in different ways, better suited to removing general atmospheric soiling across a full facade. Traditional methods are not a faster or cheaper alternative to either — they're the right choice for a specific, narrower set of problems: staining rather than general soiling, and fragility rather than robustness. We recommend traditional methods when they're genuinely the correct specification, not as a default.
Yes — it's frequently the specified method precisely because it is safe. Poultice cleaning involves no mechanical abrasion and no thermal stress, which makes it a common conservation officer requirement for the most sensitive listed fabric. Consent may still be required depending on the building and the extent of works; we advise on this at the site visit.
Longer than DOFF or TORC for the equivalent area. A single poultice application needs to remain in place for several hours to a few days, and established staining often needs more than one application. We provide a realistic programme as part of the written specification rather than quoting steam-cleaning timescales for a poultice job.
No method removes every stain, and we say so plainly rather than overpromising. Poultice cleaning is very effective on iron staining, oil and grease contamination, and many mineral and organic stains, but some deeply bound or historic staining may only partially reduce. We assess this honestly during the survey and test area before committing to a full specification.
Only where the stone or brick genuinely can't tolerate even DOFF's low-pressure steam — usually because the surface is already friable, decayed, or specifically protected by a conservation condition. For most facades in reasonable condition, DOFF remains the more thorough method, and we'd recommend it over hand cleaning unless there's a specific reason not to.