Roof Sheathing With No Vent

Static roof line vents are effective for ventilation but generally aren t recommended due to issues with leaks.

Roof sheathing with no vent.

There are three extensive patents filed. Openings along the sides allow air out of the attic cooling the space and lowering your air conditioning bill. Gable vents may circulate air through only a small percentage of your attic. Additionally ventboard now has an international patent pending pct us2011 048786.

When water flows off the edge of your roof some of it clings to the underside of the shingles and dribbles toward the fascia. The roof as you have it with soffit vents and air chutes but no high vent is a suitable design except for homes in the coldest climates with high indoor humidities. This board was at an angle not straight plum like the wall just under it. I have a mobile home and the roof was metal with no sheathing.

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. An unvented roof assembly is possible only if you keep the roof sheathing warm enough to prevent conditioned air from condensing against it. The problem was there was no overhang or soffit eave so at the end of the raffters we put a new 10 board. If you have gutters but no gutter apron to stop the water it will wick behind the gutter.

Without baffles blinders that prevent outside air from crossing over the vent a ridge vent may create almost no ventilation at all. We removed the metal roof round vent about 8 and laid plywood down. Ventboard is a proprietary innovative sheathing panel for roofs siding and flooring. Patent pending 12 987 832 patent pending 13 016 320 and patent pending 13 539 919.

Venting prolongs the life of the roof. 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 get. Eventually the fascia soffits and even the roof sheathing will rot. In northern climates the ceiling below an icehouse roof should be airtight and have a vapor retarder because the underside of the sheathing can get cold.