Atlas CrossVent should be installed directly over the vapor retarder that has been applied over the deck. CrossVent should be installed with the 8 ft. dimension parallel to the eave and with the vent strips running up the slope of the roof. CrossVent shall be fastened directly through the venting strips in accordance with fastening patterns contained in the Atlas publication, Guide Details (Current Edition) for Nail Base, CrossVent, and CrossVent RB Insulation. Leave 1/8" spacing between OSB panels to allow for expansion and contraction and stagger end joints in successive panel rows.

Atlas requires the use of Atlas Nail Base Fasteners. Refer to Atlas Design Guide for Nail Base, CrossVent, and CrossVent RB Insulation for fastening patterns and other application recommendations. Additional installation recommendations for Atlas Nail Base Fasteners are as follows:

• The fasteners should be installed using an 1800-2500 RPM (max) screw gun with a hardened #3 square drive bit. Standard electric drill guns are not recommended for installation of the Atlas Nail Base Fastener.
• Metal Decks are acceptable deck types provided they are 22 ga (min.) and 18 ga (max.).  Be sure to determine the gauge of the deck. If it is 16 ga, consult the Atlas Technical Department.

Heavy snow and ice loads, very steep pitches, high interior humidity conditions, or very high wind areas may necessitate custom fastening patterns and design. For design conditions beyond those contained in the above referenced Design Guide, a professional engineer or architect should be consulted.

Cover CrossVent with Atlas No.15 or No. 30 roofing felt. Use only enough nails as required to keep felt in place. Insulation that has become wet must be replaced with dry product prior to applying the roof coverings. Atlas also offers a wide variety of roof shingle products including three-tab and laminated shingles, as well as felts and accessories.

Ridge and soffit vents are necessary to create an effective ventilating roof system, and should be matched in ventilating capability (NFA/LF) to the CrossVent.

Vapor Retarder

Moisture vapor tends to migrate from warmer to cooler areas. In building construction, vapor retarders are used to inhibit or block the passage of moisture into walls or roofing assemblies.Sealed vapor retarders also serve as air barriers to limit the movement of moisture-laden air from the interior to the exterior. To determine whether a vapor retarder is necessary, calculations based on interior relative humidity, interior temperature, and the outside design temperature must be performed. Consult the NRCA Roofing and Waterproofing Manual (Fifth Edition) for more information regarding vapor retarders and dew point calculations.

The designer must be aware of the actual conditions of the specific installation. The designer has the responsibility to determine whether a vapor retarder is required and what type should be used; however, Atlas strongly recommends the use of a vapor retarder with a perm rating of 0.5 or less on all projects except those in extreme cooling climates. The vapor retarder should be placed over the structural deck. This recommendation is made to prevent excessive moisture (from construction materials or design conditions) from migrating through the roof assembly and causing ridging of asphalt shingles. For more information on vapor retarders, refer to Atlas Design Guide for Nail Base, CrossVent, and CrossVent RB Insulation.

Limitation of Liability

The Seller shall not be liable for any incidental or consequential damages including the cost of installation, removal, repair or replacement of this product. The Buyer’s remedies shall be limited exclusively to, at Seller’s option, the repayment of the purchase price or resupply of product manufactured by Atlas in a quantity equal to that of the nonconforming product. Atlas distributors, agents, salespersons or other independent representatives have no authority to waive or alter the above limitation of liability and remedies.