COR-A-VENT
®
Installation and Information Guide.
Easy Installation: One person can easily install the handy four-foot COR-A-VENT sections.
All you need is a hammer, circular saw, chalk line, utility knife, tape measure and a caulking gun.
Here’s an installation overview for a standard pitch* gable roof application:
®
Important–close off exposed center openings at
both ridge ends to prevent infiltration.
1. Measure a 3" slot, 11/2" each side of ridge centerline. This allows
for a 2x ridge board or smaller. Snap chalk lines the entire length of
the ridge. Cut slot with a circular saw and clean out debris. Set saw
depth so as not to cut roof rafters. Stop the slot 12" short of any
ridge end, intersecting ridge or obstruction (such as a chimney).
If Architectural Shingles, Shakes or roofing with an irregular
surface is used, apply a bead of caulk to roof deck
before installing vent. This will seal any gaps that
could allow weather penetration under the vent.
2. Nail one shingle cap at each end of the ridge, as with
conventional application. Use End Plug in the exposed end on
first and last sections of vent, caulk in place. Center first piece
on ridge and nail, keeping end of vent 1/2" from end of roof.
Set 4 nails 1/2" from ends and 2" up from edge on each corner
of vent, add 2 nails in center of vent 2" up from edge. Repeat
this step at the other end of the ridge. For V-300, use the
Folded End Cap technique shown on back page.
2"
3. Continue applying COR-A-VENT, working from ends to
middle. This technique helps remove any dips or sag in the
ridge. Align center with previous pieces, making sure vent
matches roof pitch before nailing. Continue nailing until
entire ridge is covered. Use a utility knife to cut last piece to
length. Caulk where bottom edge of end caps rest on roof.
4. Center shingle cap on vent and nail. Nail line for cap
shingles is to be 2" – 21/2" up from edge. Continue nailing
until all vent is covered with ridge caps. Be careful not to
overdrive nail. Nail head should be flush with top of shingle,
without indenting it. Pre-forming caps in cold weather helps
avoid cracking.
Be sure to use fasteners** long enough to penetrate vent and roof deck when nailing the vent and ridge cap on.
Heavyweight, architectural and re-roof installations require a longer nail than the standard installation.
In high wind areas, use a washer headed nail to prevent shingle cap “blow off”. Or, apply a 1/4" to 3/8" bead of
roof cement between the ridge caps, 3/4" up from the bottom edge of shingles parallel to ridge.
COR-A-VENT Ridge Vents are sized for residential and light commercial buildings up to 60 feet wide.
Please call COR-A-VENT before using our ridge vents on buildings wider than 60 feet.
*Standard applications V-300® or V-600® – 3/12 - 16/12 pitch. For steeper pitch/wide ridge beam applications see complete installation sheet or see us on the web at www.cor-a-vent.com.
**Nail requirements for standard vent and ridge cap installation: V-600 - 21/2" roofing nail, V-300 - 11/2" (with 3 tab shingles installed on new construction or after complete roof tear off).
Hip Installation Instructions
End Views
COR-A-VENT RIDGE VENTS W/ENHANCED SNOW SCREEN
END VIEWS TYPICAL
If the ridge length is too short to install the recommended amount of ventilation,
COR-A-VENT® V-300®E, FAV-20E (Fold-A-Vent®), or V-600®E may be installed in
equal lengths on the upper half of the hips. These instructions can be used for most
shingle, shake or slate applications.
If jack rafters are 16" on center, cut the slot per our ridge installation instructions.
If jack rafters are 24" on center, blocking may be needed to prevent the roof sheathing
from sagging. Cut 2" x 4" blocks 8" long, and using 16-penny nails, nail blocks between
jack rafters and flush with bottom of roof sheathing. Cut the slot per our ridge installation
instructions. The blocks will provide support for the roof sheathing. Nail roof sheathing
to blocks with 8-penny nails. See Fig. A below. Note: When using blocking, allow
for a loss of 25% in ventilation due to the blocks.
The slot normally does not need to be cut more than half way down the hips
for open attic roofs. The vent may be run all the way down to the end of the roof
for appearance reasons, BUT DO NOT CUT A SLOT UNDER IT! This will insure
that the air is drawn in from the soffit inlet vents and exhausted out through the
ridge and/or hip vents.
If it is an ALL cathedral ceiling roof then the slot must not be cut any closer
than 3 feet up from the outside wall of the building. This will prevent any ice
build up from leaking back into the building. In areas that receive heavy snowfall,
the slot should stop 6 feet up from the outside wall of the house. The vent may
be run all the way down to the end of the roof for appearance reasons, BUT DO NOT
CUT A SLOT UNDER IT! See Fig. B below for details on how to cut the vent
where the hips and ridge come together. The vent can be cut with a utility
knife. Caulk all joints with black silicon caulking. Also, caulk end joints on the
vent coming up the hip. Using the 20-foot FAV-20E (Fold-A-Vent) will eliminate
most joints on the hip itself. (See main drawing below.)
If 3 in 1 shingles are used, run a 3/8" bead of silicon caulking down each side of
the slot, centered on the nailing surface of the vent. This will insure that the vent is sealed
down across the shingle courses and prevent water from weeping in under the vent.
If Heavy Weight Shingles, Shakes, Slate or Tiles are used: see Fig. C
below for a detail on how to install a batten strip to provide a level surface for the
vent to sit on. Batten strips need to be as thick as the thickest point of the roofing.
There MUST NOT BE ANY GAPS UNDER THE VENT or water may leak in.
11"
5 1/2"
5 1/2"
1"
ABA
V-600E 11"
2"
2"
20 sq. in. NFVA/Lineal Foot
8 1/2"
4 1/4"
4 1/4"
1"
ABA
V-600E 8 1/2"
1 5/8"
1 5/8"
20 sq. in. NFVA/Lineal Foot
11"
5 1/2"
5 1/2"
5/8"
ABA
2 1/2"
2 1/2"
V-300E 11" & FAV-20E 11"
13.5 sq. in. NFVA/Lineal Foot
8 1/2"
4 1/4"
4 1/4"
5/8"
ABA
1 7/8"
1 7/8"
V-300E 8 1/2" & FAV-20E 8 1/2"
13.5 sq. in. NFVA/Lineal Foot
3 1/4"
5 1/8"
3/4"
1"
2 1/4"
2"
ROOF-2-WALL VENT
8.5 sq. in. NFVA/Lineal Foot
V-600TE
10 sq. in. NFVA/Lineal Foot
7"
3 1/2"
3 1/2"
5/8"
ABA
2"
2"
V-300E 7"
13.5 sq. in. NFVA/Lineal Foot
COR-A-VENT RIDGE VENTS NON-ENHANCED
END VIEWS TYPICAL
11"
5 1/2"
5 1/2"
1"
ABA
V-600 11"
2"
2"
20 sq. in. NFVA/Lineal Foot
8 1/2"
4 1/4"
4 1/4"
1"
ABA
V-600 8 1/2"
1 5/8"
1 5/8"
20 sq. in. NFVA/Lineal Foot
11"
5 1/2"
5 1/2"
5/8"
ABA
2 1/2"
2 1/2"
V-300 11" & FAV-20 11"
13.5 sq. in. NFVA/Lineal Foot
8 1/2"
4 1/4"
4 1/4"
5/8"
ABA
1 7/8"
1 7/8"
V-300 8 1/2" & FAV-20 8 1/2"
13.5 sq. in. NFVA/Lineal Foot
7"
3 1/2"
3 1/4"
3 1/2"
5/8"
1"
ABA
2"
2"
2"
V-300 7" & FAV-20 7"
V-600T
13.5 sq. in. NFVA/Lineal Foot
10 sq. in. NFVA/Lineal Foot
COR-A-VENT SPECIALTY APPLICATIONS
1"
1 1/2"
1"
1 1/2"
1"
3/4"
S-400 STRIP VENT
EAVE/SOFFIT
PS-400
SOFFIT VENT
RS-400 RAFT-A-VENT
OPEN RAFTER VENT
10 sq. in. NFVA/Lineal Foot
10 sq. in. NFVA/Lineal Foot
18.7 sq. in. NFVA/22 1/2" Piece
7/16"
13/16"
3"
Insect Screen
1"
SV-3
SIDING VENT
3"
5 sq. in.
NFVA/Lineal Foot
3"
SV-5
SIDING VENT
9 sq. in.
NFVA/Lineal Foot
PURLIN VENT
METAL ROOFING/SIDING
10 sq. in. NFVA/Lineal Foot
11"
1"
IN-VENT
6.75" sq. in. NFVA/Lineal Foot
1 3/4"
MINIMUM ROOF PITCH FOR INSTALLATION – 5/12
* A=5/16" * B=3/16"
AWF=Active Weather Foil
1 /3
2"
WITH ALL 7/8" OPENINGS AS NOTED
3" .
MIN
A 7/8" MIN. OP‘G
V-600T
Alternate Installation Examples:
®
COR-A-VENT continually develops and improves applications to
meet the growing demands of architecture and new roofing materials.
The specialized details on this page have been proven in thousands
of real world installations. We don’t experiment on your job.
Roof-2-Wall Vent™
Roof to Wall Application
Shingle Roof
V-600T Metal Roof To Wall Application
SIDING
FLASHING
V-600 11" – Architectural Metal Roof Application
AIR DAM
V-600
METAL SIDING
FLASHING
HALFB PIECE 1/2"
HIGH DOME
WIND CAP
EXHAUST
3"
AIR
AIR DAM FLASHING B
SHINGLES
A
V-600T
RIDGE
FELT
IR
BOARD
TA
EXHAUST
PAPER
AUS
H
AIR
X
E
“Z”
RAFTER
RAFTER
CL
STANDING
A
OS
SEAM
UR
ROOF
E
V-600
HALF PIECE
SHINGLES
FELT
PAPER
RIDGE
BOARD
RAFTER
SHEATHING
RAFTER
TRUSS OR RAFTER
V-600 RIDGE VENT
WALL
WALL
W
FLO
AIR
CEDAR
SHAKES A
SHEATHING
FELT
PAPER
BEAD OF
CAULKING
A
V-600 Half Piece Wide Ridge Application
HIP RAFTER
1" AIR
OPENING
TYP.
BLOCKING
FASCIA
S-400
STRIP
VENT
BLOCKING
OW
FL
AIR
TIO
LA
SU
IN
EXHAUST
AIR
N
SHEATHING
RAFTER
2x4
WALL
WIDE RIDGE CAP
P
TRIM
SHEATHING
W
FLO
AIR
JACK RAFTER
1"
SLOT
ALUM.
DRIP EDGE
CAP
SHINGLES
ROOF
UNDERLAYMENT
FELT
PAPER
11
/4
BAMAX "
T
DIMTEN
.
7/8"
FLASHING
SIDING
V-600
HALF PIECE
V-300
FLAT TILE
W
AIR FLO
ROOF
STARTER STRIP
5/8" - 7/8" GAP
EXHAUST AIR TRUSS
SHINGLESOR
RAFTER
SHEATHING
EXHAUST
AIR
FELT
PAPER
TRUSS INS
UL
OR
AT
RAFTER
IO
N
VINYL
SIDING
RAFTER
OR TRUSS
12
15
2x6
RAFTER
2x4
WALL
F
AIR
EXHAUST
AIR
ENHANCED
SNOW
SCREEN™
V-300 81/2" Flat Tile Application
ENING REQUIRED
ER VENTILATION
V-300 81/2"
FELT PAPER
TILE CAP
AIR
AIR FLOW
TRUSS
AIR
FLOW
FOAM
CLOSURE METAL
FLASHING
S-400
STRIP VENT
V-600T RIDGE VENT
AIR
TRUSS
OR
RAFTER
V-600T – W/Standing Seam
Metal Roofing & High Wind Dome Cap
HIGH WIND DOMECAP TYP. APPLICATION
MINIMUM WIDTH SHOWN, CAN BE WIDER
R
V-600 11" – Architectural Metal Roof Application
A 7/8" MIN. OP‘G
V-600T
A
A
1 3/4"
MIN.
OP'G
RE
METAL ROOF WITH
STANDING SEAM
1 3/4"
MIN. OP'G.
STANDING SEAM METAL ROOF
1"
SLOT
OW
AIR FL
H
1 3/4"
A OT
MIN. OP'G IR
WALL
CAULKING
AIR DAM
FLASHING
DETAIL
B
2 5/8"
51˚
S-400 Strip Vent – Wide Overhang Application
ROOFING
VE
NT
ILA
TIO
N
ROOF
SHEATHING
CH
U
INSULATION TE
EXHAUST AIR
V-600TE
RA
FT
ER
ENHANCED
SNOW SCREEN
EXHAUST AIR
HOT
AIR
RAFTER
OR TRUSS
FELT PAPER
OW
FL
CL
OS
U
90˚
R
AI
“Z”
FLASHINGA
CL
VARIABLE TO
COMPLY WITH
A
FASTENERS, TYP.
METAL
SIDING
INSULATION B
IR
TA
AUS
EXH
Application
4"
3/
FASTENERS TYP.
V-600TE
Seam
FINAL DOME DESIGN
MUSTStanding
COMPLY
WITH ALL 7/8" OPENINGS AS NOTED
Roof to Wall
1
LOW PROFILE CAP
NOTE: IF CAP NEEDS TO BE WIDER,
V-600 CAN BE SPLIT INTO
HALF PIECES
V-600 RIDGE VENT
WALL
SIDING
TRUSS
OR
RAFTER
7/8"
MIN.
OP'G
DRIP EDGE
FASCIA
BOARD
"
TILE
ROOF
E
UT
CH
OW N
FL TIO
AIR TILA
N
VE
INSULATION
ER
FT
RA
EXHAUST AIR
SHEATHING
FELT PAPER
1 3/4" MIN. OP'G FLOW
HAUST AIR
NOTE: NO VENT ON LOW
SLOPE SIDE OF ROOF.
WHEN ROOF PITCH IS
LESS THAN 3/12.
2x6
RAFTER
ROOF
SHEATHING
PROFILE PANEL
METAL ROOFING
BASE
FLASHING
OPENING REQUIRED
A 7/8" MIN.
FOR PROPER VENTILATION
STANDING
SEAM
ROOF SHEATHING
METAL ROOF
A
EXHAUST
(1/2" TYP.)
AIR
METAL
A CAP.
FELTROOFING
PAPER & WIDE RIDGE
USE WHEN CAP IS OVER 12"
FLAT TILE
2"
ROOF
7/8" MIN. OP'G
2x6
RAFTER
ROOFING
1/
2
n
V-600TE
INSULA
TION
METAL ROOF CAP
LOW
V-600TE
ROOF
COVERING
S-400 Strip Vent – Narrow Overhang Application
V-600T – Profile Metal Roof Application
HEAVY FELT PAPER
OR WATERPROOF MEMBRANE
2
AIR FLO
W
EXHAUST
AIR
ENHANCED
SNOW
SCREEN™
SHEATHING
12
7
FL
OW
AIR
12
Roof-2-Wall
ROOF COVERING
EXHAUST
AIR
A
FRIEZE
A
BOARD
2"
2 1/2"x1/2"
SHIM
FL
OW
V-600T
CAP
FLASHING
IN
SU
L
V-300
1" AIR
REQUIRED
OPENING
A 7/8" MIN. OPENING
FOR PROPER
TYP.VENTILATION
81/2"
COUNTER
ROOF SHEATHING
FLASHING
(1/2" TYP.)
FLASHING
FELT PAPER
1" AIR
OPENING CAULKING
TYP.
SHEATHING
CAP
ALUM.
TILE
CAP
DRIP
EDGE
AIR FLOW
1"
AIR
VINYL
SIDING
W
FLO
AIR
EXHAUST
A 7/8" MIN. OPENING REQUIRED
CAP TILE
AIR
B METAL AIR
FOR PROPER VENTILATION
DAM FLASHING
DETAIL
SHINGLES
A
SHEATHING
RIDGE
FELT
SHEATHING
BOARD
V-600T
PAPER
A
ROOF SHEATHING
EXHAUST
AIR
RAFTER
RAFTER
1/2" TYP.
TILE
FELT PAPER
1" MIN
A
ROOF
OPG.
TILE ROOF
CEMENT
MORTAR
OPTIONAL
1"
TRUSS
40˚
OR
1"
1/2"/FAV-E
V-300E
8
Application – End View
4" 81/2" Hip RAFTER
SLOT
B METAL AIR DAM
ication
FLASHING DETAIL1
CEDAR RIDGE CAP
V-300E
8 /2"
PAT. NO.
5-339-582
WALL
0 81/2"
BATTEN STRIP, TO BE
2" CAULKING
DOUBLE THICKNESS
3" .
1/3
ENHANCED
OF SHAKES AT HIP A
MIN
ST
SNOW SCREEN™
U
A
XH
CEDAR
EXHAUST
ROOF
A
SHAKES
SHEATHING
A
FELT
(1/2" TYPICAL) SHEATHING
FELT
PAPER
11
/4
7/8"
PAPER
BAMAX "
TT
DIM EN
.
V-600TE
Standing
JACK
RAFTER Seam Application
HEAVY FELT PAPER
OR WATERPROOF MEMBRANE
LOW PROFILE CAP
FASTENERS, TYP.
HIP RAFTER
SHINGLES
FELT
PAPER
Roof-2-Wall Unequal Pitch Application
V-300 Clerestory Application
V-600T Modern Shed Application
V-300 81/2" Flat Tile Application
(W/Air Dam Flashing Detail)
AUST AIR
AI
R
V-600T
– "S" Tile Application
HALF
PIECE
AT
IO
N
V-600
0 11"
DRIP EDGE
FASCIA
BOARD
7/8" MIN. OP'G
STANDING
SEAM
METAL
ROOFING
WALL
META
COU
FLA
FLAS
V-6
STAND
METAL
WALL
S-400 Shed Roof Application
AIR PATH
BATTEN STRIP, TO BE
DOUBLE THICKNESS
OF SHAKES AT HIP A
EXHAUST
CAULKING
ENHANCED
SNOW SCREEN™
T
AUS
EXH ROOF
SHEATHING
(1/2" TYPICAL)
TRUSS
ation
1"
SLOT
CEDAR RIDGE CAP
V-300E 81/2"
V-300 81/2"
FELT PAPER
INSULATION
S-400 Strip Vent – Wide Overhang Application
S-400 Strip Vent – Narrow Overhang Application
RECOMMENDED
V-300E 81/2"/FAV-E 81/2" Hip Application – End View
2" MIN.
V-300 81/2"/FAV 81/2" Ridge Application
CEDAR RIDGE CAP
EXHAUST AIR
ENHANCED
1" MIN
SNOW SCREEN™ OPG.
SHINGLES
FELT
PAPER
CAULKING
SHEATHING
RAFTER
OR TRUSS
W
FLO
AIR
H
1 3/4"
A OT
MIN. OP'G IR
Roof to Wall
ROOF-2-WALL VENT
MAXIMUM 1/2'' CAP SHINGLE
OVERHANG FOR AWF
TO CLOSE PROPERLY INSULATION
OW
AIR FL
7/8"
MIN.
OP'G
A 7/8" MIN. OP'G
AIR
AIR
1"
1"
EXHAUST AIR
V-600 Standing Seam A
FLASHING
SHEATHING
11
/2"
V-300 11"
BEAD OF
CAULKING
CL
WIDE RIDGE CAP
RIDGE CAP
1"
B
Call our technical dept. for advice on your special application. Or, send
OP'G.
us a print and we’ll “mark up” where and how to vent it. Our Enhanced MIN.1 3/4"
HOT
AIR
STANDING
SEAM METAL
products can be substituted whenever an extra
measure
ofROOF
protection is needed.
(Standard)
CEDAR
SHAKES
FELT
PAPER
FA
1 3/4"
MIN.
OP'G
V-600 Half Piece Wide Ridge Application
V-300/V-600 Steep Pitch Application
SHEATHING
A
A
SOFFIT
AIR
SIDING
S-400
STRIP VENT
AIR CAULKIN
FLOW
RAFTER
COR-A-VENT Folded End Cap Instructions:
2"
V-600
13/4"
V-300
1. Turn vent piece (V-300 shown) over so routed slot is facing up.
Use utility knife to cut out a "V" shaped notch in one end of vent.
3. Fold end flap under and secure with a roofing nail – 2" for V-300
or 21/2" for V-600. This allows for the nail to penetrate an extra
layer of vent material.
2. Measure 13/4" from end of vent and make a parallel cut through bottom
4. Nail vent pieces to roof per instructions above. Be sure to caulk
between bottom edge of vent and roof at both ends of the ridge.
3 layers. For V-600, measure 2" from end and cut through bottom 5 layers.
Remove loose pieces. Be careful not to cut off top layer!!
Be careful not to touch knife blade. Always cut in a direction away from yourself. Wear proper hand and eye protection.
For the best appearance, install COR-A-VENT continuously the entire length of the ridge.
Figuring Your Ventilation Needs:
V-600 = 20 Sq. inches NFVA/lineal foot. V-300 = 13.5 Sq. inches NFVA/lineal foot.
USE BALANCED AMOUNTS
OF SOFFIT VENT
TO RIDGE VENT
V-600: Square footage of building footprint X .48 = Lineal Feet V-600 needed
20
V-300: Square footage of building footprint X .48 = Lineal Feet V-300 needed
13.5
Example: 25' x 50' = 1250 Sq.F.
1250 x .48 = 600
600 ÷ 20 = 30 L.F. V-600 needed
The above formulas will give the amount of COR-A-VENT ridge vent needed for
a 1/150 vent ratio, provided an equal or greater amount of soffit venting is used.
For a 1/300 ratio, (building code minimum) use half the amount of ridge vent.
Note: Code interpretation may vary. Consult your local building dept.
Balanced Ventilation is not only having an equal amount of ridge and soffit vents in net free inches, but
having the soffit and ridge vents balance each other on the structure. Wherever there is ridge vent above,
there should be soffit/eave/intake vents on the structure below.
Important notes: COR-A-VENT ridge vents should always be installed with soffit/eave/intake vents of equal or greater area.
All other vent openings (except soffits) should be closed off. The air passage way or “Ventilation Chute” between the inlet
(soffit/eave/intake) and the outlet (ridge) vent must not be blocked or restricted.
Call our technical service dept. for help with any
standard or specialty ridge or soffit applications.
Our website contains a complete listing of application details in
.PDF and .DWG formats for viewing or downloading.
“This material may be duplicated only for the purposes of specifying COR-A-VENT® products.
No permission is given to duplicate or otherwise copy this material for any other purpose
without the express written permission of COR-A-VENT, Inc.”
©2006 COR-A-VENT, Inc.
04/14 4-Page Installation Instructions