Protecting Glass Surfaces During Construction - Why and How?
It is a familiar scene to window cleaners everywhere. After receiving a request for a post construction window cleaning job and visiting the job site, it becomes quickly apparent that the glass surfaces were never protected by neither the window installer, the general contractor or the various trades working adjacent to glass surfaces. Subsequently the glass has been subjected to every type of post construction debris such as concrete sealant runoff, paint, wood stain, concrete, stucco residue, silicone smears, etc. The expectation of the general contractor is that this construction debris can be easily removed from the glass surface by window cleaners with no possibility of damage.
We should pause for a moment and ask - Why are glass surfaces so often left completely unprotected by the general contractor/builder? Especially since the glass industry has published clear and specific guidelines for protecting glass during all phases of construction?
To quote the second joint GANA/IWCA technical bulletin "Proper Procedures for Cleaning Architectural Glass Products" (01-0116) page 2 clearly states "During all stages of construction the glass must be properly protected from construction debris such as cement, paint, varnish, adhesives and other construction material commonly found on job sites." Why is there an urgent need to protect the glass surface during construction activities? This bulletin goes on to state; "Glass that is improperly stored or left unprotected during construction may result in glass that cannot be successfully cleaned using routine cleaning procedures. In such situations, more aggressive cleaning and restoration techniques may become necessary, such as the use of razor blades, chemical cleaning and/or mechanical polishing. Glass surface conditions that may require more aggressive cleaning techniques would include, but not be limited to, the accumulation of paint, stain or varnish overspray; mortar, concrete or cement splashing on glass; silicone sealants and/or lubricants being smeared or sprayed onto glass and frames; and sealer overspray or run-off from adjacent masonry or stone waterproofing operations. In the process of removing tenacious contaminates from unprotected glass, particles may be trapped between the razor blade and the glass, resulting in fine scratches."
An additional technical bulletin cowritten by GANA/IWCA is titled "Construction Site Protection and Maintenance of Architectural Glass" (TD 03-1003). This publication clearly states; "After installation, special attention by all trades should be given to construction activities in order to prevent exposure of glass in windows, doors and skylights to weld splatter, paint, plaster, sealants, fireproofing, and alkali and chemical attack. The subcontractor, general contractor, or builder should inspect and document the condition of the glazed materials on a daily basis. At this stage of construction, the glazing subcontractor should request, in writing, that the general contractor or builder remind other construction trades of the potential for irreparable damage to the glazed materials and to implement systems and procedures for protection." (Page 3) Another guideline is "Proper protection of glass in windows, doors, and skylights throughout the construction process and the life of a building are essential." (Page 4) Hence, it is obvious that more forethought needs to be put into proper glass protection during all phases of construction.
An emerging technology to protect glass from accumulating tenacious debris on the surface are specialty coatings that can be applied once the glass is installed and then easily peeled off once the construction is complete. Any concrete, silicone caulk, paint, wood stain, particulate silica based dirt (which can cause scratches), mineral deposits from stucco or any other source, concrete/brick sealant runoff or anything else will come right off with the film.
One such product is WindOCoat produced by General Chemical. They specialize in many different products used for protecting different surfaces during construction. This one is specifically for glass. It can be applied with a brush, a roller or an air spray gun. Even the window frames can be protected. This is truly an innovative product.
Some glass surfaces are more prone to scratching if aggressive cleaning techniques are necessary to remove debris from unprotected glass. Thus the specific guidelines;... Protect The Glass! I remember once consulting on a building that was completely covered with a silane based concrete sealant. It couldn't be scraped off or removed with 0000 steel wool. There was an alternative method but this would have required so much time it became a restoration job. If WindOCoat had been used prior to sealing the concrete all that would have been needed would have been to peal the film off and throw it away. There would have been no need to even clean the window after. This product dramatically reduces the need to use razor blades, steel or bronze wool, and or powerful organic solvents. General Chem has developed a cold weather WindOCoat (4930 white) and a warm weather WindOCoat (4880 blue). They also have a WindOCoat 1013 manufactured for Low E glass. Many of these products have been successfully tested and used by IWCA Glass Committee members.