Ventilated Roof Sheathing

The standard 1 vent space layout leaves over 92 open vent area for maximum airflow.

Ventilated roof sheathing. Zip system roof assembly combines our revolutionary integrated sheathing and flashing tape or liquid flashing to provide a sealed roof for protection against moisture intrusion during construction or if high winds strip the roof covering away. The amount of cooling provided by a well ventilated roof exposed to the sun is very small. For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. It shall consist of 7 16 optional 5 8 or 3 4 oriented strand board sheathing with 1 deep wood spacers secured to the underside of each 4 x 8 panel.

When the attic becomes part of the home to be heated and cooled open wall gable vents and roof vents are no longer feasible but the underside of the roof the sheathing and rafters can still. A strong resilient roof is a home s first line of defense when the roof deck is exposed to weather. The roof sheathing shall be cornell ventilated roof sheathing manufactured by cornell corporation p o. Thermacal 1 and 2 ventilated roof insulation panels are composite ventilated roof insulation panels combining standard osb sheathing an air space made by solid wood spacers and polyisocynurate.

The wood spacers shall. An unvented roof assembly is possible only if you keep the roof sheathing warm enough to prevent conditioned air from condensing against it. 7 16 osb is standard and 5 8 or 3 4 osb or plywood and. Save an average of 2 500 in construction costs.

This above sheathing ventilation or asv inherent to tile roof installations can be enhanced using counter battens shims or manufactured systems to raise the horizontal battens above the roof deck. 30 times stronger than equivalent plywood or osb. Box 33s cornell wl 54732 tele. Up to 1 50 ventilation ratios possible with new matrix members.

R vent is a 40 recycled ventilation mat used in cedar metal tile roof construction. The 90 open mesh creates an airspace cavity that is perfect for promoting air flow in all directions between the metal panels and sheathing. If you see dampness or frost you need better roof ventilation and some attic vents. The map at right which is based on table r806 4 of the irc lists the minimum r values required to prevent condensation in unvented assemblies in various climate zones.

Integral ventilation provides energy savings and extends the life of roofing and siding. Field monitoring of numerous attics has confirmed that the temperature of the roof sheathing of a unvented roof will rise by a few to no more than 10 f more than a well ventilated attic. Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.