Enzymatic facade cleaner: how it works and when you see results

A facade cleaner based on enzymes is often sold as biological, gentle or biodegradable. What such a product actually does is more precise, and also more limited. Below you can read how enzymes break down dirt, why the result is not always visible straight away, what they cannot handle and how to judge a product for your own facade.

What is an enzymatic facade cleaner?

In an enzymatic facade cleaner, the enzymes in the product do the work: they break down organic dirt so that it comes loose and can be rinsed off. What is sold as a biological facade cleaner is usually a product of this kind.

Enzymes are proteins that act as catalysts: they speed up biochemical reactions that would otherwise run too slowly or not at all. Amfep, the European association of enzyme producers, describes them as biological substances that catalyse very specific reactions, with each enzyme's action depending on its three-dimensional structure and its active site (Amfep). That specificity is the heart of the matter: an enzyme acts on one kind of substance and leaves the rest alone.

Which enzymes break down which dirt?

Each group of enzymes has its own kind of dirt. Proteases break down proteins, lipases fats, amylases starch and cellulases cellulose, the building material of plant fibres.

This classification comes from laundry detergents, where enzymes have long been used. Science in School, the education journal of the European research organisations in EIROforum, puts it this way: proteases remove protein stains, lipases break down fatty materials, amylases remove stains from starch-based food and cellulases break down small cotton fibres (Science in School). The enzymes in a product therefore determine which dirt it works on.

Why is the result not always visible straight away?

Because enzymes keep acting on the organic dirt after application. Part of the result therefore only shows after the cleaning.

With an enzymatic product, the process continues as long as the dirt and the enzyme are in contact. What comes loose later can be washed further away by rain. There is no fixed timeframe: it depends on the product, the type and thickness of the dirt, the surface and the weather.

That is why an enzymatic clean is best judged on a test patch. The National Park Service, which publishes guidance in the United States on cleaning historic masonry, advises letting a test patch weather before the final evaluation: ideally a full year, so that it goes through every season, and if that is not possible at least a month or two (NPS).

What can an enzymatic facade cleaner not do?

An enzymatic cleaner does not dissolve mineral deposits such as limescale, cement film or rust. Graffiti and heavy crusts also need a different approach.

This follows from how enzymes work: they break down organic substances, while limescale, cement and rust are mineral. According to the National Park Service, graffiti and paint are usually removed with a paint remover or a poultice, and heavy crusts on limestone sometimes by controlled soaking with water (NPS). Where green growth comes from and how to deal with it is covered in green growth on facades.

Is an enzymatic cleaner a biocide?

Not automatically. A product becomes a biocide through what it is meant to do: promising that it kills algae or moss is a biocidal claim, and the rules of the Biocidal Products Regulation (EU) 528/2012 then apply.

The Swedish Chemicals Agency describes a biocidal product as a product intended to destroy, control or prevent the effects of harmful organisms, other than by physical or mechanical means (Kemikalieinspektionen). If the label or the contractor promises that the product kills algae or moss, it has to be authorised as a biocide. According to the European Commission, a biocidal product cannot be placed on the market or used unless it contains approved active substances and has been authorised (European Commission). Why bleach is a poor choice is covered in bleach on facades.

What does 'biodegradable' mean on a facade cleaner?

Under the EU detergent rules, biodegradability concerns the surfactants, the soap-like ingredients that help lift dirt. That requirement applies to every detergent on the EU market.

Since 2005, Regulation (EC) No 648/2004 has required surfactants in detergents to achieve ultimate aerobic biodegradation, meaning they are fully broken down in the presence of oxygen (CESIO). That regulation is being replaced by Regulation (EU) 2026/405, which entered into force on 22 March 2026 and applies from 23 September 2029. Surfactants must still meet biodegradability requirements under it, a requirement extended from 2034 to certain other organic substances added in high concentrations (EUR-Lex).

'Biodegradable' on the label therefore reflects a basic legal requirement for the surfactants. It says little about the other ingredients, and nothing about how well the product works on your dirt or how safe it is for your surface.

How do you judge an enzymatic product for your facade?

With three documents and one test: the label, the safety data sheet, the technical data sheet and a test patch on the facade itself.

• The label. Check which use and which surfaces the product is intended for. If it promises to kill algae or moss, look for its biocide authorisation number.
• The safety data sheet. Ask the supplier or contractor for it. Among other things it sets out the hazards and how to handle the product safely, so your health and safety adviser can review it in advance.
• The technical data sheet. It should state which dirt the product works on, how to dilute and apply it, and what the manufacturer says about dwell time. A timeframe given there is the manufacturer's claim.
• A test patch. The National Park Service advises testing any cleaning method first in an inconspicuous spot, starting small, and keeping the successful test patch as the standard for the rest of the facade (NPS).

How a product and a low-pressure rinse clean a facade together is explained in what is softwash.

Frequently asked questions