If you want to keep your home comfortable, extend the lifespan of your roof, and keep your energy costs down, it’s important to have enough attic ventilation because it will keep temperature and moisture levels regulated. Proper attic and roof ventilation will keep heat from building up, which will take the pressure off your air conditioning. It can also prevent other issues (such as mold growth and roof deterioration) from developing.
How Attic Ventilation Works
Good ventilation in an unfinished attic will include intake vents that run down low along the soffits and the exhaust vents, which are placed up high at the peak or roof ridge. This allows air to flow continuously through the space. Cooler outdoor air gets drawn in through the soffit vents as humid air migrates to the highest point and exits through the vents along the roof ridge.
Why It’s Important to Have Good Roof Ventilation
Good attic and roof ventilation can eliminate any excess heat and moisture, which can cause severe damage to your home. Heat and moisture buildup can cause different but predictable problems in hot and cold climates, so any area with hot summers and cold winters can deal with the effects of both.
When it’s hot outside, the sun will beat down on the roof and raise the temperature in your attic. If it’s exposed to too much heat, the roof sheathing can warp and distort. It will also cause your roof shingles to age more quickly. If the attic floor isn’t properly or evenly insulated, the heat can radiate into the living areas (which will make it harder and more expensive to keep them comfortable).
If you live in an area that gets below freezing during the winter months, warm air that escapes into the attic from the heated living space will rise to the underside of the roof deck. As it warms, any ice will run off the roof until it reaches the outer edge (where it will turn back into ice). If this keeps happening, an ice dam will form along the eaves (which will keep any water runoff from escaping). And once it has nowhere to go, it can back up under the shingles.
The Signs of Improper Roof Ventilation
Having an inadequate ventilation system for your roof and attic can lead to a number of problems that can show up in a variety of ways. Here are some of the signs of poor roof ventilation that you should look out for:
- An unexplained increase in your heating and cooling bills (which can happen if your attic insulation gets wet or becomes less effective).
- More frequent HVAC repairs because it has to operate under a heavy load.
- A noticeable buildup of ice along your roof edge during the winter months.
- A wavy or rippled appearance to your home’s roofline and shingles (caused by the warping of a moisture-damaged roof deck).
- Rust and corrosion on the metallic parts of your attic (such as nail heads, electrical boxes, light fixtures, and parts of your HVAC system).
- Dampness, water stains, or frost on the attic side of your roof sheathing.
- Any evidence of deterioration and decay of the roof’s structural supports.
You may also experience an increase in allergy symptoms or respiratory diseases, which can be related to the spread of fungal spores throughout your indoor air supply. It can also be caused by mold growth in your attic. If you decide to check for these signs yourself, you should keep your safety in mind. Instead of climbing on your roof, walk around the outside of your home and look up from the ground with a pair of binoculars. If you go into your attic, make sure the space has enough lighting. You also want to make sure you have a solid walking path and are wearing the proper protective gear.
What You Can Do About a Poorly Ventilated Attic
If you see any signs of improper attic ventilation, you should have it inspected by a roofing contractor who can give you options on how it can be improved. A roofing contractor will also consider any of the following factors:
- The climate in your area.
- The architecture of your roof.
- The age of your shingles.
- The condition of your deck and other roofing components.
- Whether your attic floor is sealed and well-insulated.
If your roof is getting close to the end of its lifespan or if parts of it have gotten damaged, it may be necessary to do a repair or replacement (along with taking steps to install the proper ventilation in your attic).
Attic Ventilation FAQ
It may seem odd to add insulation for warmth while purposely allowing cold air to enter the attic through a ventilation system, but it’s necessary for any energy-efficient home. During the winter months, allowing outdoor air to ventilate the attic can prevent ice damming. In the summertime, natural airflow in a well-ventilated attic will remove any superheated air. It will not only protect your roof from damage but will also remove moisture. This ventilation system works with the insulation, which will resist heat transfer into the house.
Here are some common questions people ask about attic ventilation.
Why do I need to ventilate my attic?
An attic space would get very hot and humid if it’s not properly ventilated. Poor ventilation can cause your roof to have issues related to rotting and mold. The hot attic can also damage the roofing materials. Not to mention, the effect it would have on the living space below. Allowing outdoor air to come into the attic (even if it’s hot air) can be helpful in controlling your home’s temperature throughout the year.
How much attic ventilation do I need?
There’s a standard calculation that experts use to meet minimum requirements. Building codes require at least one square foot of ventilation for every 150 square feet of attic floor. But if your attic has ridge and intake vents, you’ll need to up that amount to 300 square feet of attic space for every foot of ventilation.
Which ventilation system will work best for my attic?
For many homeowners, the best system will provide a balanced supply of intake vents at the roof’s lower edge while achieving exhaust ventilation at the roof’s peak or ridge. This will allow air to enter through the bottom of the attic, which will cause air to move to the top of the attic. This process will allow warm air to be pushed out through the top vents.
How will my attic stay dry?
Most attic ventilation systems are built in a way that will keep severe weather from affecting this space. Attic vents will usually have a baffle on their exterior to keep rain from passing through them.
How does insulation work with ventilation?
You should insulate your attic according to the recommended guidelines by making sure the insulation doesn’t block the attic vents. You can’t have proper airflow if you have insulation lining the vents.
Is my roof pitch too steep or too low for the attic vents to work?
The pitch of your roof shouldn’t have any effect on the function of the venting system. Air will hit your home at the vents on the lower part of your roof, enter the attic, and move upward through the ridge vent (regardless of your roof’s pitch).
What is the purpose of attic fan ventilation?
Attic fans pull outside air from the attic vents while pushing hot air outside. But if your attic has blocked vents and isn’t sealed from the rest of your home, they will send conditioned air out of your home and into the attic. Your air conditioner will have to work harder, which will increase your electric bill.
What are rafter vents, and how are they installed?
To completely cover your attic floor with insulation out to the eaves, rafter vents will need to be installed (which are also referred to as “insulation baffles”). By completely covering the attic floor and sealing air leaks, you can get the best performance out of your insulation. Rafter vents will make sure the soffit vents are clear. It will also make sure there’s a channel for outside air to move into the attic at the soffits and out through the gable or ridge vent.
Can I vent my attic without soffits?
If your home has narrow eaves, it may not have enough room for soffit vents. But it’s not the only way to ventilate an attic. You can also install gable or shingle venting to increase airflow inside the attic and improve attic ventilation. Gable vents are installed high on the side of a gable roof and are usually painted to match the siding or trim. Depending on where they’re placed and which direction the wind is coming from, gable vents can act as both intake and exhaust vents.
If you’re looking for one of the best roofers in Corpus Christi, be sure to get in touch with Bayfront Roofing. We have a team of experts who would be happy to speak with you!
