This specification recognizes NRCA Gutter Systems for Use with Low Slope Roofs.
The table below provides general system configurations and ultimate strength values acquired in accordance with the referenced test standard. Ultimate strength values are based on a single test for each reported design, contain no factors of safety, and are not presented as design values. Table footnotes provide additional system fastening requirements.
The table's referenced drawing numbers (Example: "G1") may be found in NRCA Construction Details. These are made available to authorized manufacturers.
The Intertek Certification Mark applied to each gutter product shows the product has been fabricated by a qualified manufacturer who is authorized to apply the Intertek Certification Mark and who is subject to Intertek periodic follow-up inspections of the manufacturing facility.
NRCA Gutter Systems
“D-Style” Two-Piece |
GT-1 Test Method and
Tested Ultimate Strength Values |
| G-1 |
G-2 |
G-3 |
| Reference Drawing No. and Description* |
Horizontal |
Vertical
Upward |
Vertical Downward |
| G1 |
6-inch Face, 6-inch bottom, 24 ga. Steel
Internal Channel Brackets 30 in. on center |
295 lb/ft
(590 psf) |
240 lb/ft
(480 psf) |
100 lb/ft. |
| G5 |
8-inch Face, 8-inch bottom, 24 ga. Steel
Internal Channel Brackets 30 in. on center |
300 lb/ft
(450 psf) |
215 lb/ft
(322.5 psf) |
50 lb/ft |
| G6 |
8-in. Face, 8-inch bottom, 0.050 in. Aluminum
Internal Channel Brackets 30 in. on center |
295 lb/ft
(442.5 psf) |
85 lb/ft
(127.5 psf) |
100 lb/ft |
| G7** |
8-in. Face, 8-inch bottom, 24 ga. Steel
Wrap Around Brackets 30 in. on center |
200 lb/ft
(300 psf) |
95 lb/ft
(142.5 psf) |
75 lb/ft |
| G8** |
8-in. Face, 8-inch bottom, 0.050 in. Aluminum
Wrap Around Brackets 30 in. on center |
155 lb/ft
(232.5 psf) |
115 lb/ft
(172.5 psf) |
115 lb/ft |
* Brackets and gutter straps attached to dimensional wood substrate with 3/8" x 3-1/2" lag bolts at 30 inches on center.
** Wrap around brackets anchored with lag bolts at gutter strap location plus a 1/4" - 10 x 1-1/2" pan head screw into dimensional wood substrate located 30 inches on center at the bottom of the bracket.
