Roof Sheathing With No Vent

We removed the metal roof round vent about 8 and laid plywood down.

Roof sheathing with no vent.

Without baffles blinders that prevent outside air from crossing over the vent a ridge vent may create almost no ventilation at all. This board was at an angle not straight plum like the wall just under it. Roofers use a circular saw to cut a long slot along the roof ridge if there isn t one then cover it with a plastic flap as shown or a flexible vinyl matrix. 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.

When water flows off the edge of your roof some of it clings to the underside of the shingles and dribbles toward the fascia. Bill rose of the university of illinois states in an unpublished report that researchers have compared the shingle temperature of both vented and un vented roof systems. The problem was there was no overhang or soffit eave so at the end of the raffters we put a new 10 board. An unvented roof assembly is possible only if you keep the roof sheathing warm enough to prevent conditioned air from condensing against it.

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. 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. Venting prolongs the life of the roof. I have a mobile home and the roof was metal with no sheathing.

Eventually the fascia soffits and even the roof sheathing will rot. Gable vents may circulate air through only a small percentage of your attic. Static roof line vents are effective for ventilation but generally aren t recommended due to issues with leaks. Openings along the sides allow air out of the attic cooling the space and lowering your air conditioning bill.

Patent pending 12 987 832 patent pending 13 016 320 and patent pending 13 539 919. Additionally ventboard now has an international patent pending pct us2011 048786. Ventboard is a proprietary innovative sheathing panel for roofs siding and flooring. If you have gutters but no gutter apron to stop the water it will wick behind the gutter.