Cor-A-Vent Product Guide

For the best appearance, install V-300 products continuously the entire length of the ridge. Figuring Your Ventilation Needs: V-300 has 13.5 square inches NFVA/lineal foot V-300 : Square footage of building footprint x .48 = Lineal Feet 13.5 V-300 needed Example: 24' x 70' = 1,680 Square Feet 1,680 x .48 = 806 806 ÷ 13.5 = 60 Lineal Feet V-300 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. Cor-A-Vent ® has promoted and taught balanced ventilation from the day we started. It’s a concept all vent manufacturers readily endorse. Unfortunately, that information doesn’t always end up in the hands of the person designing the building or installing the vents. Balanced venting helps ensure the performance you expect from ridge venting – uniform, increased airflow through the roof cavity without weather infiltration. Balanced Venting: An equal or greater amount of vent opening (square inches net free vent area/NFVA) in the soffit (intake) than at the ridge. For example, our V-300 products have 13.5 square inches NFVA per lineal foot. To balance this, you need 2 soffit/ eave/intake vents of at least 6.75 square inches per lineal foot. Balanced Venting: Continuous soffit vents are recommended, especially for venting cathedral ceilings. Wherever there is ridge vent above, there should be soffit/eave/intake vents on the structure below. Also, COR-A-VENT strongly recommends using one of our V-300 products (available in 11", 8 ½ " or 7" widths) on cathedral ceiling and hip roof applications. V-300 delivers 13.5 square inches NFVA. Because the volume of space to be vented in cathedrals is smaller, a lower profile ( ⅝ ) vent is needed to further reduce the chance for infiltration. When installing a ridge vent system, all other vent openings (except soffits) must be closed off. USE BALANCED AMOUNTS OF SOFFIT VENT TO RIDGE VENT Balanced ventilation–The right proportion of venting COR-A-VENT ® products meet or exceed all nationally recognized building codes for ventilation. COR-A-VENT products are covered under the following patents: 5,054,254; 5,339,582; 5,439,417 5,542,882; 5,603,657; 5,704,834; 5,921,863; 6,039,646; 6,213,868; 6,558,251B2; 6,589,113; D465,839 — additional patents pending. © 2017 COR-A-VENT, Inc. 01/17 V-300Flier Made in the USA. Note: Should you need any assistance in designing your ventilation system, fax or mail a sketch and information to our technical services department. COR-A-VENT will respond with recommendations for your particular building design. 1. Measure a 3" slot, 1 ½ " 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). 4. Continue to tack nail both sides of entire length of vent. Use nail pattern shown in step 3. Center shingle cap on vent and nail. 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. 2. Use a utility knife to cut out a “V” shaped notch from the centerline approximately 1 ¾ " in from edge and remove loose material (A). Cut through the bottom 3 layers of the vent as pictured (B) (located approx. 1 ¾ " from & parallel to the end). Remove loose pieces. Be careful not to cut into top layer. 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. Our website contains a complete listing of application details in .PDF and .DWG formats for viewing or downloading, or call our technical staff at 800-837-8368 . COR-A-VENT, Inc. • P.O. Box 428 • Mishawaka, IN 46546-0428 Phone: (800) 837-8368 • Fax: (800) 645-6162 info@cor-a-vent.com • www . cor - a - vent . com 3. Fold flap under and secure with a 2" roofing nail. This allows the nail to penetrate an extra layer of vent material (inset). Align starter end ½ " in from edge of roof, and centered on ridge. Be sure to caulk between bottom edge of vent and roof. Nail the starter section at points A, B & C, 2” up from edge. A B A B C