The Metal-Era Blog

Gutters & ANSI/SPRI GT-1 Standard

Published -

Updated: 8/17/2021

What is ANSI/SPRI GT-1?

After two years of development led by SPRI, the Single Ply Roofing Industry group, ANSI/SPRI GT-1 became an official ANSI standard in May 2016. Metal-Era’s own Vice President of Sales, Brad Van Dam, participated in the committee process.

Like ANSI/SPRI/ FM 4435/ES-1 is to fascia and coping, ANSI/SPRI GT-1 provides a standard test method for gutter systems that secure membrane on commercial low slope roof systems for load resistance. SPRI first addressed gutters in 2010 with ANSI/SPRI GD-1, which was the “Structural Design Standard for Gutter Systems Used with Low-Slope Roofs.” With the development of ANSI/SPRI GT-1, the design and testing standards for gutters were separated into two separate documents. Later, all design standards for low slope roof systems (including fascia, coping, and gutters) were combined into one design standard called ANSI/SPRI/ED-1.

In December of 2019 it was approved to include ANSI/SPRI GT-1 as part of the 2021 International Building Code.

When will it be adopted?

ANSI/SPRI GT-1 is vital for architects, who should consider getting ahead of the new changes before their state adapts it into the building code. Each state controls which version of the IBC they follow and when they move to a new code. It’s anticipated that several states will immediately adopt the 2021 IBC, and that additional states will follow gradually over the next few years. Click here to see what version of IBC your state currently follows.

Where will it be located in IBC?

GT-1 will be located in Chapter 15, like ES-1 is currently. You can download a copy of the GT-1 standard here.

“Gutter that are used to secure the perimeter edge of the roof membrane on low-slope (less than 2:12) built-up, modified bitumen, and single ply roofs, shall de designed, constructed, and installed to resist wind loads in accordance with section 1609 and shall be tested in accordance with Test Methods G-1 and G-2 pf SPRI GT-1”

What's at stake?

Five years ago Hurricane Matthew devastated many portions of Florida. In just one example, a 7,000 sq. ft. large box retail building saw substantial damage from 80-90 MPH winds. The cause of the damage was most likely from a loose gutter and/or flashing, which led to the roof covering peeling back. Proper gutter/flashing securement would have resulted in no loss. Instead, the retail store was hit with a $70,000 repair cost claim, $1.7 million Content Cost claim, and $1.75 million Business Interruption claim for a total $3.52 million claim paid per AIG Insurance. (Source: AIG RICOWI Presentation Slides March 2019)

How can Metal-Era help?

Metal-Era can help you understand the new GT-1 Standards and help update your low slope membrane gutter specification. Our Seal-Tite Gold Industrial Gutters are ANSI/SPRI GT-1 approved and backed by a 30-Year, 160 MPH wind warranty.



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