This option might be the updated system which most newer homes use but if you have an older home then you might need the soffit vents too.
Intake versus ridge roof vents.
The reason you do not mix them is that the ridge vent can turn the box vents into intake vents.
Roof box vents and continuous ridge vents are separated by a few differences and deciding which one to put on your roof depends on which better fits the type and situational roof you have.
Intake vents such as soffits are placed lower on the roof usually under the eaves.
Roof outlet venting with no intake venting won t work because the absence of sufficient intake of outside air to satisfy the negative pressure from air leaving at the ridge will cause draw warm air up from the building interior increasing heating costs and possibly mold or allergen movement through the building.
The homeowner has seen a drastic improvement in the air temperature in the upper level of his home.
In this back by popular demand article see the difference between roof box vents and continuous ridge vents.
That means roof ridge vents.
Even without soffit vents a ridge vent is much more effective than gable vents paulcp thinks hammer is right.
If the amount of intake ventilation cannot match the entire 40 feet of ridge vent consider reducing the width of the ridge vent slot thereby reducing the vent s nfa per linear foot to accommodate the amount of intake nfa available.
Which ultimately will increase the longevity of the roof and the life of his home.
Multiple types of vents can work together to create an equal inflow of cool air and outflow of hot air in your house.
For every square inch of ridge exhaust vent you must balance it with at least one square inch or more of soffit intake vent.
The whole point to a ridge vent is that it takes air from all along the bottom of the roof line and exits it out the top kind of like a toilet.
We added the edge vent for proper intake and replaced the roof louvers with continuous shinglevent ii ridge vents said jason vogen ceo of elite.
The problem with gables is they short circuit the air flow paulcp writes.
The soffit vents act like the air intake for the home.
It is ok to install all 40 feet of ridge vent as long as it can be balanced with intake ventilation.
If you have altering roof heights only the highest ridges should have ridge vents installed on them for the exact reason you mentioned in your comment you do not want the lower ridge vents to unintentionally become intake vents instead of exhaust vents.
This can cause a leak.
You do not want a box vent acting as in intake vent b c it will suck air in and can also suck in rain or snow with it.
Most building codes define a balanced ventilation system as one square foot of ventilation for every 300 square feet of attic floor space with half the ventilation represented by intake vents and half by by exhaust vents.
