Cleaning the exterior of your commercial or industrial building helps maintain its appearance and gives your business an inviting and professional façade. But it’s also a vital part of building maintenance that will extend its life. So, whatever type of building material you have, regular exterior cleaning is essential.

But which exterior cleaning method is right for your building? The choice between two of the most well-known methods – soft washing and power washing – depends on your building materials, the type of contaminants affecting it, and the overall surface condition – and the answer may surprise you.

Why regular exterior cleaning matters

Many property owners or facility managers can underestimate the value of scheduled professional exterior maintenance and restorative cleaning services. Regular exterior cleaning not only keeps your building looking its best, but it also:

Helps prevent long-term damage from contaminants like mould or algae
Meets building warranty conditions and regulatory standards
Boosts your brand and building’s professional appearance
Supports compliance with health and safety requirements

Soft washing vs. power washing: what’s the difference?

When it’s time to clean your building’s exterior, not all methods give the same results. Soft washing and power washing both remove contaminants, dirt, and grime, but they do it in very different ways. So, choosing the right cleaning service is vital to making sure your material surface remains undamaged.

What is soft washing?

Soft washing uses a low-pressure water spray combined with specialist cleaning fluids to remove dirt, algae, mould, and mildew for long-lasting results. It’s a gentle yet highly effective surface cleaning method that can tackle delicate painted or unpainted surface render where high or ultra-high pressure cleaning could cause irreparable surface damage. Soft washing is ideal for:

Rendered surfaces
Older or weathered cladding
Painted surfaces
Metal and aluminium cladding
Concrete, brick, and stone
Timber and composite cladding
Timber, aggregate, glass, and plastic

What is power washing?

In a complete 180º shift from soft washing, power washing (also known as pressure washing) only uses high or ultra-high pressure water (without chemicals). The process can blast away grime, stains, chewing gum, and other hard-to-remove contaminants on heavily used concrete or industrial surfaces for a super-clean, eco-friendly finish.

While power (pressure) washing certainly has its place, it’s often too powerful for buildings and property care, especially exterior building finishes. This type of heavy-duty cleaning is usually reserved for durable and robust industrial surfaces that can withstand it and where damage isn’t a concern. Even then, this level of power washing should be used with caution as, at its extreme, an ultra-high-pressure jet is capable of cutting through stone.

Power washing can still be used on a wide range of industrial and commercial surfaces and, because of its power, is best suited to:

Older concrete, brick, and stone
Maritime hold cleaning

While both cleaning methods are used and have excellent outcomes for the right surfaces, knowing the right one to choose is crucial to avoiding surface damage or results that don’t give you the finish you want.

What’s the most effective cleaning method for your building?

The South West has a wide range of building types using a diverse array of materials, from modern glass, steel, and concrete business parks and retail centres to ancient, historic, and delicate stone, brick, and masonry buildings, all of which require a custom approach to exterior cleaning. Here’s why either soft washing or DOFF steam cleaning – a chemical-free, high-temperature, low-pressure, and quick-drying process – is the best cleaning method for different materials on your building exterior (or even a mix of the two):

Metal cladding

This cladding is popular and used widely on many commercial and industrial buildings in Devon and beyond. While metal cladding is resilient and durable, it can be prone to moss, algae, and lichens, as well as air pollutants, weathering, and oxidation.

Best method for cleaning: Soft washing / DOFF steam cleaning. Using these exterior cleaning processes works well on newer or coated metal to remove significant build-up for instant results without removing paintwork or coatings.

Plastic (uPVC) cladding

This material is ideal as a low-maintenance cladding option, but over time, it can discolour due to atmospheric pollutants, develop a buildup of algae or fungus, or deteriorate, especially in coastal towns where sea salt can erode plastic.

Best method for cleaning: Soft washing. This cleaning method is ideal as the low pressure protects the material and its seals and joints, while detergents can break down organic growth without abrasion.

Rendered and painted surfaces

Colour renders such as K-rend, Sto-Rend, Mapei, or Lyme, together with renders like spar and pebble dash, are common in modern buildings but are no less resistant to the effects of weather, algae, or general dirt buildup.

Best method for cleaning: Soft washing / DOFF steam cleaning. Paint and renders can be highly sensitive to pressure washing, so soft washing, with the potential for DOFF steam cleaning for delicate areas, is the only option to clean and protect them. High-pressure water can damage, crack, or chip paintwork or render, especially after exposure to harsh or extreme weather.

Brick, stone, and concrete

Prestige Professionals team member power washing bricks

From heritage and conservation sites to contemporary office and retail blocks, properties and buildings across Devon and Cornwall often feature brick or stone façades that can attract moss, carbon deposits, stubborn stains, grime, gum, and even graffiti.

Best method for cleaning: Soft washing / DOFF steam cleaning. For hard, durable surfaces like this, soft washing is the most effective method to get a clean finish and the best results without potentially causing the damage that power washing could.

However, many historic buildings are scattered across the South West, and their delicate stonework and masonry can also attract pollutants, moss, algae, and other organic matter. However, power or soft washing should never be used on older or softer stone, as it can cause major damage. The best results for this are achieved through DOFF cleaning.

When to use each cleaning method

Your choice between soft washing and DOFF steam cleaning depends on the building surface or cladding material, level of dirt, and overall condition of your building. Power washing should only be used in areas with materials that can withstand it. Here’s a quick view guide to help you use the best method for your exterior cleaning needs:

Choose soft washing or DOFF steam cleaning for:

Cleaning delicate, rendered, or painted surfaces • Removing algae, mildew, or biological growth • Preparing surfaces for repainting or sealing
Clearing moss, mould, algae, mud, and dirt • Longer-lasting results (with periodic cleaning)
Choose power washing for:
Cleaning highly durable surface areas like concrete spaces or heavily used industrial walkways
Removing deeply embedded stains, odours, grime, or graffiti
Instant results (with regular cleaning)

Using the right exterior cleaning method not only protects your building’s exterior but also delivers a more effective, longer-lasting clean. And that saves you time, money, and hassle in the long run.

Complete exterior cleaning services from Prestige Professional

People often still refer to all types of facade and surface cleaning as ‘pressure washing’ because it’s a familiar, cover-all term. The reality is that it’s an outdated process (except for certain surfaces), and a wide range of more effective cleaning methods can be used to care for and protect surfaces and building exteriors.

Scott Williams laughing - Prestige Professional staff

But, not sure whether soft washing or power washing is right for your building? We’re here to help. As the leading provider of specialist industrial and commercial cleaning and maintenance services across Devon, Cornwall, and the South West, our expert team offers on-site cleaning assessments. We’ll inspect your surfaces and recommend the most appropriate exterior cleaning strategy for your building.

Choosing experienced professionals is essential to getting the best results for your property. At Prestige Professional, we don’t just clean. We protect your investment and restore your building’s appearance while helping you stay compliant.

For more information on our professional cleaning services, contact the Prestige Professional team today, or call 01752 424873 or email info@prestigeprofessional.co.uk.