Does Tempered glass have to have visible markings identifying it as tempered? I have been asked since a designer doesn’t want to see the marks.
IBC 2018 states:
2406.3 Identification of safety glazing.
Except as indicated in Section 2406.3.1, each pane of safety glazing installed in hazardous locations shall be identified by a manufacturers designation specifying who applied the designation, the manufacturer or installer and the safety glazing standard with which it complies, as well as the information specified in Section 2403.1. The designation shall be acid etched, sand blasted, ceramic fired, laser etched, embossed or of a type that once applied, cannot be removed without being destroyed. A label meeting the requirements of this section shall be permitted in lieu of the manufacturers designation.
Exceptions:
- For other than tempered glass, manufacturers designations are not required, provided that the building official approves the use of a certificate, affidavit or other evidence confirming compliance with this code.
- Tempered spandrel glass is permitted to be identified by the manufacturer with a removable paper designation.
I don’t believe this has changed from IBC 2015.
IBC 2015 and several earlier editions say the same thing. In most cases you should ask that the glazing unit be installed with the marking at the bottom edge, where it is less noticeable.
Dave & Richard: thank you.
Your client may not want to see the marks, but a potential buyer might. Without the marks, a buyer must assume the glass is not rated and may have to replace the glass prior to occupancy.
Without some marking on the glass how does the building official verify that the glass is tempered?
Ellis:
-I know of instances, both residential and commercial, where IGU’s needed to be replaced for occupancy permit. Some do look for the ANSI/CPSC identifiers, especially in Florida (which I recall having very thorough glass makeup labeling requirements for NOA).
-Some glass fabricators also mark “heat strengthened” plies as well.
-laser etched script is cleaner and less conspicuous than silk screened script, IMO.
In the right light, tempered glass can be identified through polarized lenses.
How did we survive before Google and Youtube?
The video shows a neat trick. But does all tempered glass comply with the requirements to meet the glazing standards?
Technically, yes.
Well if the designer does not like tempered glass markings they must have a fit on stickers indicating breakout glass.
Does the designer also raise concerns about fire rating labels on doors and door frames?
Heat Strengthened glass, which is not safety glazing, can also show strain patterns.
Qualitative assessments are not reliable per se.
Here is one way stress is measured non-destructively (if the tin side of glass is available in the IGU) -
https://www.youtube.com/watch?v=fA6TxKXyzFI
I’d trust Brett’s youtube method over mine.