I have had a few jobs recently with Low E glass windows.
On one job, the client approached me with manufacturers guidelines warning that use of a Squeegee one E glass is not recommended.
It seems to me that the big issue for window cleaners when going against manufacturers recommendations is liability. Even for pre-existing damage, it would be hard to avoid blame if you could be accused of using a method not approved by the manufacturer.
I recently wrote to a manufacturer here in Australia and raised the question of approved cleaning methods.
This was their response:
“Hi Michael, Thanks for your enquiry regarding the cleaning of Viridian Low E glass.
Viridian do not offer specific advice on the use of squeegees however our concern in cleaning with this would be the aluminium stiffening rods that form part of the squeegee having contact with the Low E coating.”
So it seems that manufacturers are mainly concerned with any metal contacting the glass… which makes perfect sense.
Nevertheless, when manufacturers clearly state that squeegees must not be used on E glass, it does put the window cleaner in an awkward position in terms of liability and blame.
I have spoken to a few other window cleaners in Australia who told me that they use pure water on the coated surface… but of course, getting a good rinse is always going to be an issue with using pure water on the interior windows. Others tell me they just use the traditional squeegee method with a lot of extra care, making sure that the scrubber is 100% free of grit, a new rubber is used each time, and the least amount of pressure is applied.
In my mind, unless a manufacturer specifically states not to use a particular cleaning method, the window cleaner has the freedom to choose. But going completely against specific warnings from a manufacturer is playing with fire.
Nevertheless, it seems inevitable that these specialized coatings do increase the liability of anyone who has to deal with them.
One manufacturer states that: “Professional glass cleaners have significant experience and access to equipment, materials and methods which the general public may not. As professional glass cleaners are acknowledged experts in the cleaning of glass, [we] offer the information on this page as general advice only for the professional glass cleaner to consider as part of the development of their own cleaning processes.”
On the one hand the above statement boosts the window cleaners status as a glass cleaning ‘expert’, but also their liability should their expertise fail.