Cladding & render cleaning

Cladding and render cleaning: the full guide

Render and cladding are the first things a building shows the street, and the first to show their age. Green algae on the north face, dark streaks under sills, run marks along render bands and a grey film of traffic dust across composite panels all make a well-run building look tired. None of it needs repainting or replacing. It needs the right wash, applied from the right access, by people who know what will and will not shift.

This guide covers the surfaces we clean, the methods we use and why we avoid pressure washing, how often façades need attention, what affects the price, and the questions property and facilities managers in London, Essex, Hertfordshire and Cambridge ask us most.

Surfaces we clean

• Through-coloured render. Acrylic, silicone and mineral renders that carry their colour in the coat rather than a paint film. These are the most common on student blocks and newer residential buildings.
• Painted render and masonry. Cleaned gently so the paint film is not lifted, and reported on where it has already failed.
• Cladding panels. Composite, high-pressure laminate, fibre cement, powder-coated aluminium and glazed spandrel panels on offices, schools and accommodation blocks.
• Brick and stone. Atmospheric soiling and organic growth, cleaned without abrasive methods that open the face of the material.
• Canopies, soffits, fascias and signage on the same visit, so the whole elevation reads as one finish.

How we clean render

Render is soft-washed. A render cleaning solution is applied at low pressure, left to work on the algae, lichen and atmospheric soiling, and then rinsed. The chemistry does the work rather than the water. A soft wash lifts organic growth without opening the surface of an acrylic or silicone render, which is what a pressure washer does, and once the surface is open it holds water and grows green again faster.

At a student accommodation site in Colchester we soft-washed every rendered elevation of a tower and a long curved block, working by rope access from the roof and from a tracked spider lift where the ground allowed. The render now has an even finish across its bands and curves and the tower reads as one colour again. Read the Colchester render cleaning case study.

Where render and window cleaning are done together, we wash the render first and clean the glass last, elevation by elevation. Render dust settles on glass that has already been cleaned, so the order matters.

How we clean cladding

Cladding panels are cleaned with purified water through carbon-fibre poles, the reach and wash method, with soft brushes and no detergent. Purified water dries without spotting and leaves nothing on the panel to attract the next layer of dirt. Panels above pole height are reached by rope access or from a MEWP.

Not everything responds to water. On a five-court student campus in Hatfield we cleaned every cladding panel that could be reached from the ground and removed bird fouling from the named elevations. Some panels carried construction residue that had bonded to the face while the panels were off the wall. We cleaned the worst of them a second time, filmed the result, and reported which panels had not responded and why, with a recommendation for a builder's clean by hand from a MEWP. Read the Hatfield cladding cleaning case study.

That is the standard we work to on every façade job. You get the panels that clean, and a clear, photographed record of anything that needs a different treatment.

What the service involves

1. Survey and test patch. We look at the substrate, the soiling and the access, and test-clean a small area so we know what the finish will be before we quote.
2. RAMS and access plan. A site-specific risk assessment and method statement, with the access method for each elevation: rope access from tested anchors, a MEWP or spider lift, or poles from the ground.
3. Protection. Windows, planting and paving below the wash are protected, and run-off is managed so it does not stain the ground or reach drains untreated.
4. The clean. Soft wash for render and masonry, reach and wash for cladding, and hand cleaning from a platform for anything stubborn. Windows and frames are cleaned last.
5. Report. Before and after photographs of every elevation, video where it helps, a certificate of completion, and a note of any damaged or displaced panels, cracked render or failed sealant we found while we were up there.

How often façades need cleaning

• Render: a soft wash every two to three years keeps the finish even. That was our recommendation at Colchester. North-facing and sheltered elevations, and anything under trees, green faster than the rest.
• Cladding: once a year on most buildings, often on the same visit as the window clean. Panels near main roads, railways or building sites collect dust faster.
• After building work: a builder's clean before handover, because construction dust bonds to panel faces if it is left through a summer.
• Before a sale, letting or inspection: a façade clean is the quickest way to change first impressions of a building.

Standards and safety

• Work at Height Regulations 2005. Every job is planned under the regulations, using rope access from tested anchors, MEWPs or ground-based poles rather than ladders.
• Manufacturer's guidance. Render systems and cladding panels come with cleaning instructions, and most warranties exclude damage from high-pressure jets and abrasive tools. Our methods stay inside those conditions.
• COSHH. Cleaning solutions are handled to their data sheets, run-off is contained, and operatives wear the protection the product calls for.
• Occupied buildings. Residents and staff are told each morning which elevations are in use and asked to keep windows closed while we wash.

What affects the price

• Area and height. Priced by the square metre of façade, with the access method set by height and ground conditions.
• Soiling. Light atmospheric dirt is a single pass. Heavy algae, lichen or bonded construction residue takes longer and may need a second treatment.
• Substrate. Delicate renders and coated panels need gentler methods and more dwell time than brick or fibre cement.
• Access. Ground-based poles are the cheapest. Rope access and MEWPs cost more but avoid scaffolding, which on a façade clean often costs more than the clean itself.
• Combining work. Cleaning the windows, gutters and canopies on the same visit saves a separate call-out.

Where we work

We clean render and cladding on student accommodation, residential blocks, offices, schools and retail buildings across Greater London, Essex, Hertfordshire and Cambridge. Recent façade work includes the render tower and curved block in Colchester and the five-court campus in Hatfield, both cleaned while fully occupied.

Cladding and render cleaning questions

Can you pressure wash render?

We do not. High pressure opens the surface of an acrylic or silicone render, drives water into it and makes it green faster. A soft wash at low pressure, with the right cleaning solution and a proper rinse, gives a better finish and does not damage the coat.

How often should render be cleaned?

A soft-wash maintenance clean every two to three years suits most buildings. Elevations that face north, sit under trees or are sheltered from drying wind may need it sooner.

Will a soft wash remove the green algae for good?

It removes the growth and leaves the surface clean. Algae will return over time on any exposed render, which is why we recommend a maintenance cycle rather than a one-off clean.

Can you clean cladding while the building is occupied?

Yes. Both of our recent façade projects were fully occupied. We tell residents each morning which elevations are in use, keep windows closed on those elevations and manage the run-off at ground level.

What if a panel will not come clean?

We clean it a second time, film the result and tell you why it has not responded. At Hatfield the cause was construction residue bonded to the panel face, and we recommended a builder's clean by hand from a MEWP. You get evidence to take to the contractor responsible rather than a bill for a clean that did not work.

Do you clean the windows at the same time?

Yes, and we recommend it. Render dust settles on glass, so we wash the render first and clean the windows last, elevation by elevation.

Do you need scaffolding?

Very rarely. Rope access from tested anchors, MEWPs, spider lifts and ground-based poles reach almost every façade without it, which keeps the cost and the disruption down.

What do I receive at the end?

Before and after photographs of every elevation, video where it helps, a certificate of completion and a note of any damaged panels, cracked render or failed sealant we found.