Render Cleaning in Cardiff
We use safe soft wash solutions and low-pressure methods to restore tired and stained walls without damage.
Render Cleaning & Surface Soft Wash in Cardiff and South Wales
Cleaning render usually involves applying a low-pressure washer along with a suitable cleaning solution, or using soft washing techniques with specialised detergents. High-pressure washing is generally discouraged, as it can cause damage to the render. Mild bleach mixtures or dedicated render cleaning products are effective in removing dirt and stains, helping restore the building’s clean and refreshed appearance.
Cardiff Window Cleaner Ltd has many different solutions for all surfaces including all kinds of render, stone and brickwork to powder coated surfaces that look drab and faded after weathering.
Why render gets dirty — and how we fix it
Common Render Cleaning Problems in Cardiff Properties
South Wales properties are often exposed to damp weather, traffic pollution, and organic growth — all of which affect render over time.
- Algae and red stains – thrive in damp, shaded areas and spread fast
- Black mould and moss – unsightly and can slowly damage the render
- Pollution and road grime – leaves render looking dull, grey or streaked
- Salt or lime run-off – creates white staining on walls
- General weathering – render fades, darkens or develops patchy spots
These issues affect both appearance and longevity. Cardiff Window Cleaner Ltd uses approved render cleaning solutions to safely remove these stains and restore a clean, uniform finish.
A method that protects your render
Our Render Cleaning Process
Cardiff Window Cleaner Ltd follows a careful, step-by-step soft wash approach:
- Assessment – Type of render, staining level, and accessibility
- Biocide application – Apply approved solutions (e.g. Blackwash or Algoclear Pro)
- Dwell time – Let the product break down algae and organic growth
- Low-pressure rinse – Gently wash away loosened dirt and dead spores
- Follow-up – Some renders continue self-cleaning for days after
- Optional treatment – For difficult staining or re-growth prevention
No harsh jet washing. No render damage. Just lasting results.
Common Reasons for Render Cleaning
- Algae: Algae can leave unsightly green or red stains on your render. It grows in damp conditions and spreads quickly, making your walls look discoloured and dirty.
- Dirt and pollution: Over time, dirt from traffic, factories, and the environment can build up on your render. This doesn’t just make it look dull—if left alone, it can attract even more dirt and grime.
- Moss and mould: Moss, lichen, and mould often grow in shady or humid areas on exterior walls. Not only do they look bad, but they can also damage the render over time if not removed.
Smart solutions, not shortcuts
Render Cleaning Solutions & Equipment
Blackwash is the only sodium hypochlorite-based soft wash biocide that has full government approval from:
- The Irish PCD (Pesticide Control Division)
- The UK HSE (Health & Safety Executive)
- REACH (Registration, Evaluation, Authorisation & restriction of Chemicals)
We use Blackwash as a stand-alone soft wash solution, or in conjunction with power washing and/or Biocidal Wash.
What to expect on your quote
Render Cleaning Cost in Cardiff
Render cleaning costs depend on size, height, condition, and access:
| Type of Property | Unit | Example Price Range |
| Small Terraced House | 1 side | £150 – £250 |
| Medium Semi-Detached House | 2 sides | £250 – £350 |
| Large Detached House | 3 sides | £350 – £500 |
Factors that affect pricing include:
- Type of render (e.g. K-Rend, silicone, lime)
- Stain level (e.g. heavy algae vs. light pollution)
- Height and access (e.g. extensions, rear walls)
- Optional add-ons (e.g. uPVC, gutter, or window cleaning)
Contact us for a free, no-obligation quote tailored to your property.
Commercial Surface & Render Cleaning
Many make the assumption that when external surfaces become tired or weathered then the only way to make them look like new again is to either paint or replace the surface with new material. The two environmentally friendly products we use are ‘Benz Blackwash’ and ‘Algoclear Pro’. This Video highlights their effectiveness.
Specs
Render Cleaning with BENZ Biocidal Wash
UK Health & Safety Executive (HSE) approval certificate number: 9936
Irish Pesticide Control Service (PCS) number: 9807
Specs
Render Cleaning with BENZ Blackwash
UK Health & Safety Executive (HSE) approval certificate number: 10161
Irish Pesticide Control Service (PCS) number: 9841
Render Cleaning FAQ
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What is the best way to clean render?
The best way to clean render is by using specialised soft wash solutions such as Benz Blackwash or Algoclear Pro. These products are designed to break down and remove algae, moss, and dirt without causing damage to the surface. When combined with the right techniques, such as low-pressure washing and biocidal treatments, they can restore the render to its original condition.
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Should old render be removed?
Not necessarily. Most old render can be cleaned effectively with professional cleaning solutions and techniques. This reduces the need for costly replacements or painting. However, if the render is severely damaged or structurally compromised, removal and replacement may be required.
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Why does render get dirty?
Render accumulates dirt due to environmental factors like pollution, algae or moss growth, and exposure to the elements such as rain and wind. Over time, these factors can cause discoloration or streaking, making the surface look weathered and unsightly.
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How often should you clean render?
The frequency of cleaning will depend on the location and exposure of your property. Typically, render should be cleaned every 2–4 years to maintain its appearance. Areas with high humidity or pollution may require more frequent cleaning.
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Should you pressure wash render?
Render is a delicate surface, and high-pressure washing is not recommended as it can cause damage. Instead, low-pressure cleaning methods combined with soft wash solutions are preferred, ensuring the render is effectively cleaned without harm.
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How much does it cost to have a render cleaned?
The cost of render cleaning varies depending on the size of the property, the extent of dirt or staining, and the cleaning method used. Contact us today for a customized quote tailored to your needs.
Additional Services We Offer
Roof Cleaning
Roof areas often contribute to staining on rendered walls due to run-off from moss and dirt. That’s why pairing render washing with roof cleaning makes perfect sense. It ensures your entire property faсade remains clean and stain-free. Our service also helps reduce water damage risks over time.
Moss Removal
Render surfaces are particularly prone to moss and algae growth, especially in shaded or damp areas. Our moss removal service tackles these organic stains at the root to prevent rapid regrowth. By combining it with render cleaning, we ensure your building stays fresher for longer.
Flexible Working
One off jobs or flexible contract terms to suit all businesses for all our cleaning services.
Safe Contractor
For peace of mind we are Safe Contractor Approved, fully insured and carry out all work to highest standards
Cleaner Cardiff
For cleaner windows, shops, factories and buildings in the Cardiff area - contact us with your requirements.