Instructions / Assembly

RIDGERUNNER
™
Roof Deck: Use only over a well-seasoned, supported wood deck, tightly constructed with
maximum 6" wide lumber, having adequate nail-holding capacity. Plywood decking as
recommended by The Engineered Wood Association is acceptable.
For ridge vent to function properly, it must be the only high or exhaust vent for the vented
attic space. Do not use with gable-end louvers, turbines, roof vents or power vents.
Slope Restrictions: Use only on slopes between 3/12 and 16/12.
STEP 1
Calculations for a Balanced Ventilation System
To achieve a “balanced system” with Cobra
®
Ridge Runner
™
ridge vent, there must be
an air intake system (i.e., soffit or undereave vents). For proper ventilation, the amount
of undereave ventilation must equal the amount of ventilation at the ridge.
NOTE: Consult local building codes for other ventilation requirements.
NOTE: In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.
To determine the minimum square feet of net free ventilating area (NFVA)
needed for a balanced ventilation system, use the following formula:
Cobra
®
Ridge Runner
™
ridge vent has 12.5 square inches of NFVA per lineal
foot. To determine how many feet of Cobra
®
Ridge Runner
™
ridge vent is
needed, use the following formula:
1/2 x (Min. Sq. ft. of NFVA needed) x 144/12.5 = Min. lineal feet of ridge vent needed.
To determine the amount of undereave vent required, use the following formula:
X = NFVA (Sq. in. per. lin. ft.) of the undereave vent or intake vent system selected
1/2 x (Min. Sq. Ft. of NFVA needed) x 144/X = Min. lineal feet of undereave
vent needed.
APPLICATION INSTRUCTIONS
Exhaust Vent For Ridge Roof
STEP 2
Instruction For Slots
After calculating the total length of Cobra
®
Ridge Runner
™
ridge vent needed, determine
the necessary slot opening required.
Note: If installing on an existing roof, remove the cap shingles from the ridge.
Roofs without a ridge board: cut an opening along the ridge
7
/
8
" on each side (Figure A).
Roofs with a ridge board: cut an opening along the ridge 1
5
/
8
" on each side (Figure B).
Note: Maximum slot opening is 3
1
/
4
" wide.
Mark off and cut the slot opening, making sure that the ends of the opening stop at least
6" from any end walls and 12" from chimneys and hip intersections (Figure C).
Where short ridges (dormers, ridge intersections) are used, mark and cut the slot making
sure that the end of the opening stops at least 12" from the ridge intersection (Figure D).
5
/8
”
1
1
/4
”
3
5
/8
”
1
Fig. A
Fig. B
Fig. C
Fig. D
Sq. ft. of attic floor space
Min. Sq. ft. of NFVA needed
300
=
20'x11
1
/2" Roll