The idea is that wind goes into one gable vent and then pushes the air out of the attic and through the secondary gable vent on the other side of the attic.
How to vent an attic without soffit.
Place the roof vent over the hole.
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.
Venting solutions for roofs with no overhang or soffit install special roof intake venting products that work at the lower edge of the roof decking underneath the first course of shingles.
For proper ventilation it isn t enough for air to simply get into your attic.
Remove the shingles in the area where the vent is to be installed.
For an attic without soffit vents you may have the option to use gable vents instead.
Once they are in place you can then place the batts or blankets or blow insulation right out to the very edge of the attic floor.
Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.
If you don t currently have gable vents then it would be a good idea to install this vent.
Insert the jigsaw and cut the hole.
The venting drip edge seems to be the easiest and most common way to go.
Rafter vents should be placed in your attic ceiling in between the rafters at the point where your attic ceiling meets your attic floor.
Drill a hole inside the shape for the jigsaw blade.
Typically you would have a gable vent on each end of the attic.
Draw it on the roof deck.
The design of many older houses omits eaves which maximizes the amount of sunlight.
They call this a venting drip edge.
Problems when roof has no overhang.
Smart vent a special roof eaves vent product that provides a 3 4 opening about 6 above the top of the roof drip edge.
The molded polystyrene baffles available at home centers and lumberyards for about 1 each form channels that hold insulation at bay and direct incoming air upward.
How to vent an attic with no eaves the function of soffit vents.
Determine the shape of the hole needed for the vent.
Finally to ensure that the airway to the vent remains open staple a ventilation baffle to the plywood sheathing in each rafter bay.
One great alternative to a soffit ventilation system is to install an intake vent right at the lower edge of the roof.
If there is plenty of soffit venting and if you have a relatively tight ceiling then the makeup air will come from outside which is desirable summer and winter.