How to soft wash in hot weather

Working in hot weather can make soft washing more challenging. High surface temperatures increase evaporation, causing your solution to dry before it has enough contact time to work effectively. Contractors often refer to this as "boil-off".

Knowing how to manage boil-off will help you achieve better cleaning results, use your chemicals more efficiently and produce more consistent results.

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Why boil-off happens

High temperatures make both Lightning Cleanze and Bio Cleanze more reactive while also increasing evaporation.

If your solution dries too quickly, contact time reduces, which can affect cleaning performance and increase chemical consumption.

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Pre-wet hot surfaces

Before treating surfaces exposed to direct sunlight, lightly wet them with clean water.

Pre-wetting helps to:

• Reduce surface temperature.
• Slow evaporation.
• Increase contact time.
• Produce more consistent results.

During extreme heat, it can help to have a second operator pre-wetting the surface immediately before treatment.

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Work in smaller sections

Avoid treating large areas in one pass.

Instead, divide the work into smaller sections so you can maintain the correct dwell time before the solution begins to dry.

This approach is especially important on roofs, dark-coloured render and south-facing elevations.

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Adjust your dilution

Very hot conditions can change how your chemicals behave.

Rather than automatically using stronger mixes, assess the surface conditions and, where appropriate, increase the dilution on the hottest elevations. Cooler, shaded elevations can often be treated using your normal working dilution.

Always adjust your dilution to suit the conditions on site rather than using one ratio for every surface.

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Choose the right time of day

Whenever possible, carry out soft washing during the cooler parts of the day, such as:

• Early morning.
• Late afternoon.
• Overcast conditions.

Avoid treating surfaces that have been exposed to direct sunlight for long periods wherever practical.

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Working with Lightning Cleanze

When conditions are exceptionally hot, start with a slightly weaker working solution and assess the cleaning performance before increasing the concentration if required.

This approach allows you to achieve the desired result while reducing the risk of rapid evaporation.

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Key takeaways

• Pre-wet hot surfaces before application.
• Work in small, manageable sections.
• Adjust dilution to suit the conditions.
• Treat cooler elevations first where possible.
• Work during the cooler parts of the day.
• Monitor dwell time and avoid allowing the solution to dry before it has finished working.

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We wish you the very best in your softwashing business.

Team Benz

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Further help

Looking for more practical advice? Browse our growing collection of Trade Tips or use our website search to find answers to your soft washing questions.

You can also download our Product Documentation Pack, which includes application and dilution guides, SDS, PDS, RAMS, PPE guidance, COSHH information and more.

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