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.
Roof ventilation without soffit.
Soffit vents and eaves are placed at the lower extremes of the roof and provide the intake ventilation.
This occurs through the rising of warm air and the falling of cooler air.
For proper ventilation it isn t enough for air to simply get into your attic.
Be certain that the hole is between the rafters.
They call this a venting drip edge.
Draw it on the roof deck.
Intake vents such as soffits are placed lower on the roof usually under the eaves.
But if you don t have eaves or if you have shallow soffits like me ventilation can be a challenge.
Install special roof intake venting products that work at the lower edge of the roof decking underneath the first course of shingles.
Roof ridge vents are placed along the ridge line of the roof.
Here are examples of inadequate intake ventilation.
For an attic without soffit vents you may have the option to use gable vents instead.
Problems when roof has no overhang.
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.
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.
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.
Weird attic layouts may be a part of it.
However without soffit vents that makeup air comes from indoors a situation that is not desirable in any season.
With old homes it can be very difficult to properly ventilate the attic for a variety of reasons.
Venting solutions for roofs with no overhang or soffit.
One great alternative to a soffit ventilation system is to install an intake vent right at the lower edge of the roof.
The design of many older houses omits eaves which maximizes the amount of sunlight.
I m presuming that the roof has good eave detailing so that rain does not enter at the beam.
If you live in an older home your roof might not be constructed for roof ridge or soffit vents.
Typically you would have a gable vent on each end of the attic.
The two roof ventilation options intake vents and exhaust vents should be placed to take advantage of the natural increased speed of air circulation.
Determine the shape of the hole needed for the vent.
Place the roof vent over the hole.
Ridge vents are used for exhaust or outflow of moisture heat and stale air.
How to vent an attic with no eaves the function of soffit vents.
The venting drip edge seems to be the easiest and most common way to go.
Smart vent a special roof eaves vent product that provides a 3 4 opening about 6 above the top of the roof drip edge.