Ridge vents are wonderful additions to any attic, but do they work without soffit vents? The answer is yes, but there are some drawbacks to do so. This article will look at using ridge vents without soffit vents and explain the benefits and drawbacks of doing so.
Ridge vents can work without soffit vents, however, this won’t be very energy efficient. Without soffit vents, the ridge vents will draw air from some other inlet on the roof like a gable, but this will limit the extent of air circulation in the attic. This can cause an increase in heat loss from the house due to natural convection.
Ridge vents are working at their best, with soffit vents installed as intake to ensure adequate ventilation that will keep your attic within ten degrees of the ambient temperature in whatever season. Furthermore, this combination will ensure the longevity of insulation, woodwork of the roof in general and will attribute to the optimum temperature in your attic.
Let’s see how the ridge-soffit ventilation system work.
Working of Ridge-Soffit attic ventilation
For soffit-ridge attic ventilation, the soffit vents act as the fresh air inlet and the ridge vents as the exhaust vents. Soffit vents, if you already don’t know, are installed at the soffits of the house which is the lower portion of the attic. Due to wind and natural convection ambient air enter at the bottom and are exhausted at the top.
Under normal circumstances, a ridge vent works in a similar way to a chimney. The ridge vent creates a draft, and the air is sucked in through the soffits and exhausted through the ridge vent. This air movement takes place along the way of least resistance, and air entering the soffits will move between the shingles/water barrier/plywood and the ceiling insulation of the attic ceiling until they are exhausted by the ridge vent. The system works marvelously to keep the air temperature below the roof as close as possible to the ambient temperature, and thereby, the attic is kept cooler.
There must be no blockages that prevent the flow of air along the path of least resistance from the soffit vents to the ridge vents, as blockages will have a negative effect during any season.
Soffit vents are neglected and sometimes covered with a layer or more of paint that blocks the airflow. The holes above the soffit vent should be big enough and unobstructed to allow free air passage. Blockages will lead to a hot attic and mildew and mold forming on the rafters and insulation of the attic. Any obstruction of the airflow through that cavity will have an influence on the airflow through the cavity, and the exhaust effect of the ridge vent. The blockage will therefore cause a hot attic and a shorter lifespan of your roof in general.
In winter, the ridge vent needs to exhaust, and it will draw warm, humid air from the attic through any opening that will accommodate airflow. This will lead to heat loss through the attic ceiling and an increased energy demand due to the loss of warm air through the attic, resulting in a higher energy bill. Insulating the attic ceiling with closed cell spray foam to ensure that it is air and watertight is the way to go if you want to ensure that air is not drawn from the attic if there is a problem with your ridge vent-soffit vent system. That way, your attic will stay cool in summer and warm in winter.
What if you have no soffits vents?
But what if your roof doesn’t have an overhang with soffits and thus space for installing soffit vents?
In such a case, you must remember that you are going with the second best and not the best solution. For example, ridge vents work one hundred percent with soffit vents, whereas anything less is substandard.
1. Gable Vents
Unobstructed Gable vents installed on either side of the roof between the level of the shingles/ water barrier and the ceiling insulation of the attic might work. However, normal vented air likes to enter the attic lower down on the first third of the roof.
Your attic temperature should be within 10 degrees of the ambient temperature if your ventilation is adequate. You might be required to staple a radiant barrier on top of the rafters to get the ideal temperature.
2. Eyebrow Vents
Small eyebrow vents installed as close as possible to the perimeter of the roof might work well. Keep a balance between your intake (Eyebrow vents) and your exhaust (Ridge vents).
3. Drip Edge Vent
If you are installing a new roof, you might install drip edge vents. Drip edge vents are small cavities between the shingles/water barrier and the attic ceiling insulation that will intake air for your (exhaust) ridge vent.
The best intake vent is a soffit vent for air to circulate under your roof and be exhausted by a ridge vent. If you need to adapt the system, it is possible, as discussed but do not expect the same results as you would have had with soffit vents in combination with a ridge vent. Some or a combination of alternatives might give you results that are close to ideal.