R-Panel Roof Curb

R-Panel Roof Curb (High Rib Roof Curb) fits any R-Panel metal roof system. Custom curb dimensions and configuration are built to meet any skylight or rooftop equipment requirements. Pitch correction to match roof slope as specified. Rib-to-rib (R&S Layover) side flanges come standard for a complete weather tight seal. Economical flat flange models are also available. Roof curb may include a custom finish that matches the roof color. Roof Curbs install under the roof panel on the up-slope and over the roof panel on the down-slope, which results in a shingled watershed condition for complete weather-tight condition. In addition, a 20-Year Warranty comes standard on all aluminum curbs.

Roof Curbs For: HVAC | Exhaust Fans | Skylights | Gravity Vents | Pipe Penetrations

Aluminum Roof Curb with Layover Side Flanges and Damper Shelf
Upblast Roof Exhaust Fan on Custom Roof Curb

Features

Custom-fabricated to match any metal roof profile
Integral upslope cricket for water diversion
Aluminum (preferred) or aluminized steel construction
Full-penetration/continuous welds
Mill or custom color finish
Partitioned top for HVAC as specified
Backer-channel, sealants and fasteners for install
CAD drawings supplied with every order
Structural calculations available upon request (fee)
Aluminum curbs carry a 20-Year Warranty

Specifications

Material	0.80 aluminum 18 GA, 14 GA or 16 GA Aluminized steel 1″ Rigid Insulation R6.5 (higher R-Values available)
Construction	Full penetration welds, thoroughly tested Mitered corners for true square top
Curb Up-slope	Flange installs under panel Panel closures welded or shipped loose Integrated 4″ high water cricket Min 9″ between up-slope curb wall and closures
Curb Down-slope	Flange installs over panel Caps (straps) welded or shipped loose Minimum 3″ down-slope flange
Curb Side Flanges	Rib-to-Rib, layover to next natural high rib Minimum 3″ between curb sidewall and high ribs
Curb Top	Level top when specified Skylight curbs slope with roof
Dimensions	6″ – 8″ curb height on up-slope (custom heights available)
Finish	Aluminum mill finish Powder coat (standard colors) Kynar (exact match)
Accessories	14 GA backer-channel Sealants, fasteners
Certifications	Engineering calcs (additional costs apply)
Warranty	20 Years (aluminum) 1 Year (steel)

TYPE IF CURB (Internally Flanged)

Same design / construction as above with the following exceptions:

Curb Up-slope	Up-slope base flange breaks inward 1-1/2″ Includes 2-peice water diverter assembly and backer channel
Curb Down-slope	Down-slope base flange breaks inward 1-1/2″ Integrated caps in curb wall accept panel highs
Curb Side Flanges	Side base flanges break inward 1-1/2″
Backer Channel	Integral backer channel Included with all IF curb kits

Options

Curb Liner	Conceals insulation, mill or white finish, complete kit for install
Ridge Mount	Installs on ridge condition, double pitched
Collar Top	Square-to-round transition
Over / Over	Up-slope and Down-slope over roof panel
Non-Insulated	Cost savings when insulation not required
High R-Value	2″ thick insulation for R14 value
Damper Shelf	Damper support for exhaust fan
Duct Supports	Blank-offs, duct supports for HVAC equipment

Curb Model Guide

Provide roof panel make, model, seam spacing and pitch when requesting quote

Model

L
x
W
x
H

Side Flanges

Closures/
Caps

Upslope/
Downslope

Curb Top

Insulation

Material

Finish

Options (add all that apply)

MBR

R-Panel / High Rib

L: Layover
R: Flat Flange
F: Internally Flanged

1: Fixed / Welded

2: Loose / Field Located

3. None

4. Up-slope Flat, Down-slope Offset

U: Under / Over
O: Over / Over

L: Level
S: Slope w/ Roof

Y: Insulated
X: Not Insulated

A: Aluminum
G14: 14 Gauge Galvanized Steel
G16: 16 Gauge Galvanized Steel
G18: 18 Gauge Galvanized Steel

M: Mill
P: Powder Coat
K: Kynar

CL: Curb Liner
RM: Ridge Mount
CT: Collar Top
DS: Duct Supports

Example

MBR-48x96x8-L1SY-18AM-CL: Metal building roof curb with outer dimension of 48″x96″ and 8″ high at the upslope curb wall. Features layover type side flanges with fixed / welded closures and caps and a non-pitched-corrected top flange. Fabricated of aluminum, mill finish and a curb liner (double wall).

R-Panel Roof Curb Terminology

Closure: seals trapezoidal panel at up-slope curb opening (under panel)
Cap: seals trapezoidal panel at down-slope curb opening (over panel)
Seam Clip Side Flanges (C): side flanges integrate with roof panel seams (includes seam clip)
Layover Side Flanges (L): side flanges extend and layover next natural high rib
Flat Side Flanges (R): flat side flanges 3″ typical
Internally Flanged (F): perimeter base flange breaks / seals inside curb wall
Under / Over: up-slope installs under, down-slope installs over roof panel
Over / Over (OO): up-slope and down-slope flanges install over roof panel
Floating 2-Curb System (FC): Inner weight-bearing curb and outer flashing curb (heavy equipment)
Ridge Mount (RM): Inner weight-bearing curb and outer flashing curb (heavy equipment)
Curb Liner (CL): white or mill finish liner on inside of curb wall; conceals insulationFloating
Collar-Top (CT): square-to-round transition for pipe penetrations

All curbs custom-sized to meet project specifications. CAD drawings are provided with each curb order (submittal package) including HVAC partitions, damper shelves and panel rib/seam contour placements.

Documents

Additional curb configurations available, call for details

Product Description	Model	Submittal	Specifications	Installation	Warranty
Layover Side Flanges	MBR-L	PDF	WORD	PDF	PDF
Flat Side Flanges	MBR-R	PDF	WORD	PDF	PDF
Internally Flanged	MBR-F	PDF	WORD	PDF	PDF
Ridge Mount	MBR-R-RM	PDF	WORD	PDF	PDF
Collar Top Adapter Square-to-Round Transition	MBR-CT	PDF	WORD	PDF	PDF

Accessories	Model	Submittal	Specifications	Installation	Warranty
Backer Channel Layover Side Flanges	SUB-MBR-L	PDF
Backer Channel Flat Side Flanges	SUB-MBR-R	PDF
Backer Channel Internally Flanged Curbs	SUB-MBR-F	PDF

Additional Support Documents

Description	Curb Type	Roof Type	Installation Guide
Downslope Loose Contour	Internal Flange	High Rib / R-Panel	PDF
Curb Wall Section View	Relevant to All Curb Types	Relevant to All Roof Types	PDF

Optional engineering calcs by Structural P.E. to ensure local codes and load tolerances are met.

What is the primary purpose of a standing seam roof curb?

Designed to fit trapezoidal or vertical standing seam roof panels, these curbs connect rooftop equipment to the roof.

What materials are commonly used for these curbs?

Common materials include aluminum or galvanized steel.

What are the insulation options with roof curbs?

These curbs come standard with 1″ rigid insulation, with options for higher R-Values available.

How does the roof curb’s construction ensure water doesn’t seep in?

The curbs are manufactured with full penetration welds and features like integrated 4″ high water crickets for effective water diversion.

Is there a warranty on these roof curbs?

Aluminum curbs come with a 20-Year Warranty, while Steel Curbs have a 1-Year Warranty.

R&S Insights Blog

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