Attic Ventilation Pitfalls to Avoid & Roof Vent Tips

Roofing is an integral part of the home that we should pay close attention to. It shields us from harmful outdoor elements such as rainfall, hot sun, and dangerous rodents.

When the roof is poorly installed and doesn’t allow moisture inside the house, it breeds mold and mildew. These are harmful elements that can cause bacteria and create long term ailment to your household. Therefore, you need to ensure that your attic ventilation is working correctly. Below are the attic ventilation pitfalls to avoid.

How Many Vents Do I Need?

The benchmark of the total number of vents needed is approximately one vent for every 300 square feet of the attic space if there is a vapor barrier in the attic. Meaning, if your attic area is 600 square feet, you will need roof vents totaling to two square feet.

Both the intake and exhaust vents should be equally divided. You can use it with any roof design combination. The vent rating depends on the net free space, which is the vent air inflow space and vent air outflow. However, if the slope of the roof is higher than 6:12, it means that the attic space’s volume will be more than the real square footage.

Can I Have Too Much Attic Ventilation?

Too much ventilation in the attic can easily damage the roof and increases utility bills. The roof accumulates a lot of moisture during air circulation and disrupts airflow through the attic, which damages and weakens the spots, resulting in leakages.

Your air conditioner will need to use more strength during the warm months to keep up with outdoor air. You will notice a considerable difference in utility bills when you have appropriately fixed ventilation.

Using More Than One Type of Exhaust Vent

Using more than one exhaust vent on the roof is misguided, making homeowners think that more than one is better. The truth is that it does more harm to your roof. Exhaust vents such as gable-mount power, ridge vents, roof-mount power fans, and roof louvers are better installed single.

Mixing them is dangerous as it will short-circuit the attic ventilation system. A short-circuited system becomes ineffective, causing weather infiltration through the attic. It becomes easy for air to flow in because the roof can no longer resist it.

Using not more than one exhaust vent and ensuring it is appropriately installed allows airflow from the intake to the exhaust vents. It then flushes out warm and moist air under the surface of the roof deck.

On the other hand, if you use two or more types of exhaust vents, the lower exhaust vent blocks airflow from reaching the primary exhaust vent and causing the space to lack ventilation.

Tip: Unlike exhaust vents, you can use two or more intake vents. There will be no short circuit occurrences since the intake vents are usually in the same wind pressure stretch.

Take Control of the Intake Vents

Ensure that the intake vents are in place during the roofing process. A roofing contractor may not be careful to check this since they are less concerned about it after installing the exhaust vents. If you don’t keep a keen eye on it, your roof may end up without intake vents, creating an imbalance.

If a contractor does not consider installing intake vents, they need to hear from you whether there are enough vents in place to pair up with the attic ventilation system. You may need to hire another roofing contractor to take charge of the additional intake vents.

The contractor needs to check the existing intake vents, find out if they are correctly fixed, have proper air circulation, and no interruption. In the case of elements like debris, dirt, and paint blocking airflow, you may need to ask the contractor to recommend another professional to take up the work.

Tip: Get a smoke candle from an HVAC store and use it to check if there are debris and dirt in the intake vents and find out if there is smoke puff reaching out to the exhaust vents from the intake vents.

Improper Installation

An imbalanced combination of the intake and exhaust vents will cause an inefficient and ineffective attic ventilation system. The system gets powerful, effective, and efficient when the two vents get balanced. The intake net free space should transcend over the exhaust net free space.

Tip: In case of an imbalance of the attic ventilation system, the roofing contractor should ensure that there are more intake vents than exhaust vents. The extra intake vents transfigure to the exhaust vents on the sheltered section of your house.

Giving Attention Only on the Hot Season

The attic should be given an all-season consideration and not only the hot weather. Many people only think of how hot it gets during the summer and forget the cold during winter. Attics become too hot in summer when they get to the extreme, causing indoor discomfort and high power consumption.

However, during winter, you will experience a drop in the outdoor temperatures, and the attic moisture becomes an issue due to the water vapor produced during summer. When the intake and exhaust vents get correctly balanced, it removes moisture before condensation, which prevents the building materials from getting damaged.

It would be best if you considered attic in all seasons to keep you comfortable by fighting heat in the hotter seasons and building up moisture in the winter. Attic ventilation is also a crucial element that offers defense against ice dams during snow seasons.

Tip: There is a high accumulation of water vapor from household activities such as breathing, cooking, cleaning, and showering. The water vapor gets safely removed by a balanced attic ventilation system.

Omitting Attic Spaces

The attic ice dams cause most winter condensation challenges due to the bypassing of the attic. Any open spaces or gaps on the attics allow air to escape due to poor sealing, causing the attic to get condensed.

The bypasses also cause snowmelt due to the uneven roof deck temperatures, which results in ice dams. There needs to be a thorough roof inspection to identify any possible attic bypasses and ice dams and get them back in order.

Tip: The possible affected attic areas to inspect are electrical and false plumbing walls, drywall joints that separate the rectangular timber plate, ceiling, recessed can light, and attic access entryway.


Getting proper ventilation in the house should be a priority for every homeowner. Taking into account the attic ventilation pitfall above will give you a reliable roof above your head. Some roof ventilation issues could be beyond your reach, and you may need to get roofing professionals to fix up the complicated areas to avoid more roof damages.

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