How Strong are GlasMaster Boxes?

GlasMaster Boxes are designed and formulated specifically for their intended application. These applications are derived from ANSI standards that are accepted industry-wide for underground enclosures. As shown in the following table, the specific load rating for an enclosure that receives non-deliberate vehicular traffic is much higher that an enclosure that only receives pedestrian loading. We highly recommend selecting the load ratings that are specified for the application as stated the ANSI/SCTE 77 2002 specification.

ANSI TIER Rating Structure


Loading Requirements
Light Duty
Pedestrian traffic only
Vertical Test Load 13.3 3000 lbs.
Sidewalk applications with a safety factor for
occasional non-deliberate vehicular traffic. 
Vertical DesignLoad
Test Load
22.2 kN
33.3 kN
5000 lbs.
7500 lbs.
Lateral Design Load
Test Load
28.7 kN
43.1 kN
600 lbs./sq. ft.
900 lbs./sq. ft.
Sidewalk applications with a safety factor for
non-deliberate vehicular traffic. 
Vertical Design Load
Test Load
35.6 kN
53.4 kN
8000 lbs.
12000 lbs.
Lateral Design Load
Test Load
28.7 kPa
43.1 kPa
600 lbs./sq. ft.
900 lbs./sq. ft.
Driveway, parking lot, and off-roadway applications
subject to occasional non-deliberate heavy vehicular traffic. 
Vertical Design Load
Test Load
66.7 kN
100.1 kN
15000 lbs
22500 lbs
Lateral Design Load
Test Load
38.3 kPa
57.5 kPa
800 lbs/sq ft.
1200 lbs/sq ft.
Deliberate vehicular traffic applications
Certified precast concrete, cast iron, or AASHTO recognized material



The ANSI/SCTE 77 2002 “Specification for Underground Enclosure Integrity” was published in 2002 and relates specifically to underground enclosures that are commonly used as meter boxes, valve boxes, junction boxes, and splice boxes. Many other standards have been used in the past, but are not specific to these types of enclosures, which can lead to ambiguity and cause confusion. For this purpose, all GlasMasters Boxes are built and conform to the ANSI/SCTE 77 2002 specification. To ensure our customers that they are installing the proper enclosures, each product is identified with the corresponding Tier rating that the product was built for.

4x Stronger / 3x Lighter

All GlasMasters Boxes are manufactured out of lightweight/high-strength materials, and are typically three times lighter than traditional precast concrete enclosures. All products listed as a small enclosures conform to the OSHA standards for one man or two man lift. Large enclosures, such as vaults, may require the use of a lifting device. However, many of the large enclosures can be shipped as individual components and assembled in the field without the use of equipment.


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