This document provides installation instructions for installing a horizontal standing seam roof curb. The instructions are as follows: 1. Attach sub-frames to support the roof curb opening. 2. Mark and cut the roof panel to size for the curb opening. 3. Slide backup channels under the roof panel. 4. Apply sealants around the curb perimeter and set the curb in place over the opening. 5. Fasten the curb to the roof panel using self-tapping screws.

1. R O O F C U R B I N S TA L L AT I O N I N S T R U C T I O N S :
H O R I ZO N TA L S TA N D I N G S E A M PA N E L
p: (800) 284-1412 f: (903) 759-3598 www.lmcurbs.com 827 fisher rd longview, tx 75604

2. ROOF CURB
INSTALLATION INSTRUCTIONS
HORIZONTAL STANDING SEAM PANEL
Installation Check List:
_____Attach Sub-Frames Step 1
_____Layout Curb on Roof Panel Step 2
_____Back-up Channels Step 3
_____Apply Sealants & Set Curb in Place Step 4
_____Fasten Curb to Roof Panel Step 5
PARTS LIST
Flat Washer Polyurethane Sealant Caulk
Triple Bead Sealant Tape
Nut
14 Gauge Galvanized Steel Subframe
Bolt 5-1/2” tall
Length is equal to the purlin spacing minus
1-3/8”
Mounting Clip
Back-up Channels( eld notch)
#14 - 1 1/8” Neoprene
Self-Tap Screw
BEGIN INSTALLATION
1 ATTACH SUB-FRAMES (framed opening is already installed)
Attach mounting clips to sub-frame and align the top of the sub-frame under Roof Purlin
Sub-frame
vertical box of roof curb and ush to the bottom side of roof sheets. Use the
mounting clip as a template, mark on purlin where 7/16” holes are to be drilled.
Once holes are drilled, attach mounting clips to purlins using at washers, nuts,
and bolts (see drawing 1.1). Finger tighten all hardware, then upset threads to
secure nuts. Attach sub-frames to mounting clips using at washers, nuts, and Drawing 1.2
bolts (see drawing 1.2). Flat washer
Nut
3/8” x 1” Bolts
Mounting clip
Drawing 1.1
Roof Purlin
*NOTICE* Sub-frame max. loading 500 lbs.
WARNING! Page 1
ALWAYS USE FALL PROTECTION WHILE
WORKING AROUND ROOF OPENINGS.

3. ROOF CURB
INSTALLATION INSTRUCTIONS
HORIZONTAL STANDING SEAM PANEL
2 LAYOUT CURB ON ROOF PANEL
Mark cut lines by setting roof curb(s) in place on roof panel (see
Cut Line
drawing 2.1) (DO NOT USE LEAD PENCIL). Upslope cut line will be s7
”
inu
bm
3” less than outer edge of curb base ange (see drawing 2.2). o f cu
r
gth
Downslope cut line will be 4” less than outer edge of base ange Len
(see drawing 2.2). Remove exterior panel leaving the insulation
face showing (see drawing 2.3) and cleanup all metal shavings and
debris.
Drawing 2.1
Top View Roof Panel
Layout throat opening on the insulation Throat Opening
Roof Opening
and cut opening (see drawing 2.2).
Insulation
Cu
rb
Ba
se
Fla n ge
ng Fla
e se
Ba
rb
Drawing 2.3 Cu
Drawing 2.2
*Notice* Sub-frames and purlins not shown in the above picture.
3 BACK-UP CHANNELS
Notch back-up channels (see drawing). Slide back-up channels
under roof panel on top of sub-frames. Do not screw back-up Edge of roof opening
channels to subframes. They will be secured when curb is
fastened down.
Cut leg of channel and fold under to form
notch for sub-frame (typically 4 places).
Back-up Channel
Ce
nte
Ou rL
ine
Drawing 3.1
tsid
eD of
im Su
b-F Back-up channels in place
en ram
sio
no e
fB
ack
-up
Ch
a nn
el
WARNING! Page 2
ALWAYS USE FALL PROTECTION WHILE
WORKING AROUND ROOF OPENINGS.

4. ROOF CURB
INSTALLATION INSTRUCTIONS
HORIZONTAL STANDING SEAM PANEL
4 APPLY SEALANTS & SET CURB IN PLACE
Apply a strip of sealant tape and generous bead of caulk on the upslope side of the roof curb and on downslope side of the roof
panel , apply a generous bead of caulk where the panel overlaps the side of roof curb and where side of roof curb overlaps panel
(full perimeter) before setting roof curb in place (see drawing 4.1). Position roof curb over roof opening and lower into place,
shift curb to align with sub-frames and roof panel.
Prepare Upslope Panel Seams
/2” Mark rib for cutting Fold over rib and
11 Remove marked
section of rib crimp tight.
Apply caulk
Must ll end of standing
A B
before folding
C seam with caulk.
The downslope of curb is to be The upslope of curb is to be
installed OVER the roof panel. installed UNDER the roof panel.
Roof Curb
Caulk
(full length of curb)
Roof Panel
Caulk Caulk
(apply as shown) (apply as shown)
Caulk
(full length of curb)
Sealant Tape
Drawing 4.1
*Notice* Sub-frames and purlins not shown in the above picture.
WARNING!
ALWAYS USE FALL PROTECTION WHILE Page 3
WORKING AROUND ROOF OPENINGS.

5. ROOF CURB
INSTALLATION INSTRUCTIONS
HORIZONTAL STANDING SEAM PANEL
5 FASTEN CURB TO ROOF PANEL
Fasten curb to roof panel using #14 - 1 1/8” neoprene self-tap screw Roof Panel
on 4” centers (see drawing 5.1). DO NOT FASTEN CURB OR ROOF
PANEL TO SUB-FRAMES. Please ensure all self-tap screws are
properly tightened before moving to the next step.
Must ll end of
closure with caulk.
Self-Tap Screws
Drawing 5.1
*Notice* Sub-frames and purlins not shown in the above picture.
COMPLETED INSTALLATION
**Clean up installation debris before leaving area.
WARNING! Page 4
ALWAYS USE FALL PROTECTION WHILE
WORKING AROUND ROOF OPENINGS.