Residential Window Inspections

It is absolutely impossible to correctly inspect windows before they have been professionally cleaned. The reason involves what is called insulating unit seal failure. When this happens the unit (which consists of two plates of glass separated with a small space and an inert gas in between) sucks in some of the air and with it water vapor. This condenses on the inside of the unit causing a slight cloudiness. The more vapor, the greater the condensation, the more intense the cloudiness. This effect is usually very difficult to detect when it first happens. It requires a trained eye, and of course a proffesionally cleaned window. Many windows in home might have already lost their seal. But no one would know. If you are purchasing a home, especially one with a lot of insulating glass windows, it would be in your best interest to request a professional that is familiar with this condition, to clean them. There are other problems that will show up under the trained eye. Such as gasing inside of the unit (not from seal failure). It looks very much the same however. Also I have personally seen rag marks, fingerprints, and much dust, inbetween the two plates of an IG (insulating glass) unit. Of course these are all sealed in permanently. Problems can result from the misplacement of the tin side of float glass. The low e coating might have been put on the wrong side when the IG unit was manufactured. Such coatings could also be damaged. If the low e coat is soft, it must always be located in between the two plates where it is protected. Because when it is touched, the mark left cannot be removed. This is why I have seen many thumbprints of different colors permanently left in between the two plates of an IG unit. Other problems include fabrication debris on tempered glass. This is a defective surface. Damage from scratches or hard water deposits. Various types of etched surfaces can also be a problem. Tempered glass can be extremely wavy from the tempering oven. All of these potential problems and more , can be detected by the professional window cleaner who has been trained by experience. Not your local home inspector.

Henry Grover Jr.
Glass Tech Consulting
gtcnews@hotmail.com