Should windows and window/door frames be masked when soft washing?

November 02, 2019

Should windows and window frames be masked when soft washing?
Benz Lightning Cleanze softwash biocide based on sodium hypochlorite (SH)

A customer asked us: "A surveyor has specified the soft washing of render with Benz Lightning Cleanze and to mask the windows. What is your experience of masking windows and window frames when applying Lightning Cleanze at 5:1 on render, with some overspray and run-off inevitably going onto the windows and frames?"

We replied: We've never masked windows and have never experienced any long-term issues with window frames or glass.

In hot weather the glass can look unsightly for a very short time until you rinse off with de-ionised water but our softwash products have never caused any damage.


Quick tip: A temporary colour change can occur on white uPVC – for example on certain window and door frames, facia, and soffit – in hot weather and strong sunlight.

This is caused by the increased reactivity of Lightning Cleanze when exposed to heat and direct sunlight. The uPVC will return to normal after 2 to 48 hours, depending on the strength of your mix.

To stop this happening we have a hosepipe or pressure washer with rinsing nozzle on hand ready to immediately rinse off any product that gets on the frames..

Our advice is to treat a small, out of the way, test area of a window and window frame. Then show the surveyor and explain that this is all that will result from overspray onto the frame.


Quick tip: If the surveyor insists on using masking tape, then check the windows and frames will not react to it. Also, in my experience of painting houses, it is best practice to get the tape off as soon as possible because the adhesive can bake onto the frames in hot weather and it can be extremely difficult to remove.

We hope this information is helpful and sincerely wish you great success in your soft washing business,

Ben, Leo, Fiona, Stevie & Anthony

PS: After completing the first softwash treatment of a property, put your customer on a "Clean & Maintain" ongoing maintence programme.

Your customers will enjoy a permanently clean property and you, the contractor, will enjoy a steady stream of repeat business. A win-win arrangement for everyone.

Click here to explore the full range of Benz softwash cleaning products

Benz Softwash Bio Cleanze DDAC biocide & Benz Softwash Lightning Cleanze SH sodium hypochlorite biocide

Leave a comment

Comments will be approved before showing up. Please revisit to read our response.


Also in Benz Trade Tips

How to clean sh stains from lead flashing with Oxy Cleanze
How to clean sh stains from lead flashing with Oxy Cleanze

June 25, 2022

Sodium hypochlorite can react with lead flashing and discolour it. Benz Oxy Cleanze can fix this.

Click the link on this page to find out how ...

View full article →

When to pressure wash – and when not to pressure wash?
When to pressure wash – and when not to pressure wash?

June 17, 2022 4 Comments

After pressure washing (power, jet) algae spores rapidly recolonise, and properties return to square one in a very short time. So what's the alternative?

Click the link on this page to find out ...

View full article →

How long can I store diluted Benz Bio Cleanze (softwash ddac biocide)?
How long can I store diluted Bio Cleanze (softwash biocide)?

June 15, 2022 2 Comments

How long can diluted Benz Bio Cleanze can be stored for, and still be ok to use on another job?

Click the link on this page to find out ...

View full article →