Glass Standards Frequently Asked Questions
The most common blemishes observed are:
- Fingerprints inside the IGU
- Dirt or debris inside the IGU
- Water spots or mineral deposits
Glass is a material made primarily from sand and as such may have perceivable blemishes; however, they may not be immediate cause for rejection. The window, door and skylight industry has developed an in-depth and detailed set of standards that address most blemishes. However, to assist homeowners in determining if a blemish merits replacement, this simplified glass inspection procedure has also been developed.
In general, industry standards call for glass inspection to be made with 20/20 vision (naked eye or corrected). Samples are to be viewed in the vertical position at the distance as specified in the standard. Visual inspection distances can vary from one industry standard to another and can also vary by the type of blemish found and by the glass product type.
To assist homeowners in determining if a blemish merits replacement, a simplified glass inspection procedure has been developed for homeowners.
Yes, there are several consensus-developed industry standards for glass. Applicable standards depending on the glass type may include: ASTM C1036, ASTM C1048, ASTM C1172, ASTM C1376, as well as ASTM E2190 and IGMA TM-3100 for insulating glass units (IGUs). Definitions for these standards are provided within the Glass Standards and Guidelines page.
These are minimum standards for the industry. Contact the manufacturer of your window for their specification.