The (GANA) Glass Association of North America published the following:
Glass Informational Bulletin on the cleaning architectural glass products:
Glass Informational Bulletin GANA 01-0300
Proper Procedures for Cleaning Architectural Glass Products
Architectural glass products have an impact on the comfort of today’s homes as well as the atmosphere and work environment of commercial work places. They offer views of the surroundings and provide natural light. Deciding where we work and live is often affected by glass usage and condition as well as design and thermal comfort.
The visual and aesthetic clarity of architectural glass needs to be maintained. Cleaning during the construction process as well as routine maintenance is required to keep up the visual and aesthetic clarity. Glass products can be permanently damaged during cleaning if proper procedures are not followed. Glass fabricators and producers suggest the following methods for the proper cleaning of glass surfaces.
Interior and exterior glass surfaces should be cleaned as soon as dirt and residue appear. Concrete residue or mortar that has run down or maybe splashed on can especially be damaging. It should be washed off right away. Before you start to clean, you need to know if the glass is tinted, reflective or clear. Reflective glass means that surface damage will be more noticeable compared to other types of glass. Special care must be taken if the reflective surface is on the interior or exterior surface. The coating can be removed by scratches and the light transmittance can be changed. Tinted and reflective surfaces don’t clean well in warm temperatures, and therefore should not be cleaned it direct sunlight. Residue and cleaning solutions can fall on windows below you, so start at the top of the building and work your way down. Also be careful that windy conditions don’t blow residue and cleaning solutions on nearby windows that have already been cleaned.
During construction the windows can acquire an excessive amount of dirt and grime. Soak the windows first with clean water and soap. this should loosen the dirt and debris. Use a commercial window washing solution that is non abrasive. Apply the solution to the window with a strip washer, brush or a non abrasive applicator. Apply the solution uniformly over the entire window. Us a squeegee to remove all of the solution from the surface of the glass. Take care not to trap any abrasive particles between the cleaning materials and the glass. The metal parts of the cleaning tools should also no touch the glass surface. Window sealants, frames and gaskets have the potential for deterioration, so the cleaning solution and water dried in these areas.
It is strongly suggested that you test the window surface. Clean only a small area on one window first. Then inspect it for damage or scratches. Be sure to test a window that is in direct sunlight. It is harder to detect scratches on a window that is in the shade.
During manufacturing and shipping, the glass industry is careful to protect all glass surfaces to avoid scratches. Most of the glass damage that occurs is from non glass trades people that are working near the glass. Such as iron workers, carpenters, landscapers and painters who are also part of the construction process. They could splash something on the glass or lean tools against it. Then if they try to clean the glass and do it incorrectly, they may damage the glass as well.
A common mistake made is the use of razor blades as well as other types of scrapers. Even the larger or wider blades will probably scratch or permanently damage the glass. The entire glass industry does not either recommend or condone using metal blades or knives on glass surfaces. The only exception is when paint or other material cannot be removed by any other cleaning process. Only then a new 1 inch razor blade may be a solution, and it should ONLY be used on clear class with no coating. Scrape in one direction, never back and forth. Scraping back and forth can cause hairline scratches that are not immediately visible, but can be seen under certain light conditions.
If you have a situation where you are unable to clean the glass, contact the glass manufacturer for instructions on proper stain removal.
Members of the Glass Association of North America (GANA) publish guidelines for jobsite cleaning and protection of architectural glass products. The GANA encourages general contractors, building management and glazing contractors to follow the gleaning guiltiness and handling provided by the glass fabricator an producer so that glass is not damaged.
The GANA web site (www.glasswebsite.com) has more information on glazing and glass applications and links to other members that provide more technical resources.
The Glass Association of North America (GANA) has created these Glass Handling Guidelines to provide basic information on general proper procedures for taking care of architectural glass products. They are not trying to say that one particular way of glass cleaning should be used in all cases or even in any one application. Those who use this Bulletin have to be responsible and be sure the cleaning instructions of the glass manufacturer are followed. GANA does not claim any responsibility for any results relating to the using of the information provided, for any errors or omissions contained in the Bulletin, and for any damage or liability or for loss of any kind as a result of using this Bulletin.
Quick-Reference Guide to Cleaning Architectural Glass Products
The following Do’s and Don’ts are an addition to the Glass Association of North America (GANA) Glass Informational Bulletin – Proper Procedures for Cleaning Architectural Glass Products:
The following are things to DO:
- DO clean glass when residue and dirt are on the surface
- DO check if glass surfaces have an exposed coating
- DO take special care when coated glass surfaces are involved
- DO try to avoid cleaning coated and tinted glass surfaces when in direct sunlight
- DO start cleaning from the top of the building and then proceed to lower levels
- DO pre soak the glass surface with clean water and a soap solution to loosen debris and dirt
- DO use a non abrasive, mild commercial cleaning solution for windows
- DO remove all of the cleaning solution with a squeegee
- DO dry all cleaning solution from frames. window gaskets and sealants
- DO clean one small area of a window first and check to see if it has caused any damage
- DO follow the glass manufacturers specified cleaning recommendations
- DO ask other trades people not to allow other materials to make contact with the glass
- DO watch conditions that may damage the glass and try to prevent them
- DO read the GANA bulletin on glass cleaning before you begin to clean glass