But if you don t have eaves or if you have shallow soffits like me ventilation can be a challenge.
Roof ventilation without soffit.
Drill a hole inside the shape for the jigsaw blade.
Normal vented air likes to enter the attic lower down near the bottom third of the attic and as it passes through it will exit higher up near the top third of the attic space.
I m presuming that the roof has good eave detailing so that rain does not enter at the beam.
Soffit vents and eaves are placed at the lower extremes of the roof and provide the intake ventilation.
The venting drip edge seems to be the easiest and most common way to go.
Install special roof intake venting products that work at the lower edge of the roof decking underneath the first course of shingles.
Remove the shingles in the area where the vent is to be installed.
They call this a venting drip edge.
The design of many older houses omits eaves which maximizes the amount of sunlight.
However without soffit vents that makeup air comes from indoors a situation that is not desirable in any season.
It makes sense that the wettest spots are near the beam because that s the most likely site for humid air leakage from the indoors.
Typically you would have a gable vent on each end of the attic.
Venting solutions for roofs with no overhang or soffit.
This occurs through the rising of warm air and the falling of cooler air.
Weird attic layouts may be a part of it.
Don t install intermittent or occasional or faux soffit intake venting or vents with too little opening area such as we show in the photo at left.
Intake vents such as soffits are placed lower on the roof usually under the eaves.
How to vent an attic with no eaves the function of soffit vents.
The two roof ventilation options intake vents and exhaust vents should be placed to take advantage of the natural increased speed of air circulation.
Be certain that the hole is between the rafters.
For an attic without soffit vents you may have the option to use gable vents instead.
Insert the jigsaw and cut the hole.
Vents at the soffits are intermittent or spot vents or are simply too small.
If you live in an older home your roof might not be constructed for roof ridge or soffit vents.
Roof ridge vents are placed along the ridge line of the roof.
One great alternative to a soffit ventilation system is to install an intake vent right at the lower edge of the roof.
Smart vent a special roof eaves vent product that provides a 3 4 opening about 6 above the top of the roof drip edge.
Place the roof vent over the hole.
For proper ventilation it isn t enough for air to simply get into your attic.
Problems when roof has no overhang.
Determine the shape of the hole needed for the vent.
If i had an older home without soffits i would strongly consider just completely air sealing the attic and adding foam insulation totally removing the need for ventilation.
Draw it on the roof deck.