If you live in an old home, it will likely have insulation but lack ventilation in its attic. Placing insulation in your attic is important; it helps to regulate the temperature by making your home warmer in winter and cooler in summer. But your attic also needs proper ventilation.
A+ Insulation explains why ventilation for your attic is necessary, and how you can install it.
If your attic doesn’t have proper ventilation, the insulation will be useless. There are a couple of things that could happen to your insulation, and the effects depend on the seasons.
The Effects of an Unventilated Attic in Winter
During winter, warm, moist air rises from the rooms. This air gets trapped in the attic, warming the roof. When cooler air enters the attic, condensation occurs, which then creates mold or wood rot, and cause serious damage to the roof and ceiling supports. The insulation could then become soiled, rendering it useless in helping keep the house warm.
Another problem arises when snow accumulates on your roof, and the warmer air in the attic melts the snow. Snowmelt then flows down to your roof’s gutters and re-freezes at the bottom of your roof. Over the course of the day, more and more snow melts, trickles down to the edges and re-freezes. When this happens enough times, the ice can eventually crack open the bottom shingles of your roof, channeling snowmelt to your attic, and also affecting the insulation.
The Effects of an Unventilated Attic in Summer
In summer, heat may build up in the roof’s base over the course of a day, making the temperature in the attic and the home as high as the outside temp, or higher. This phenomenon is called solar gain. What this does is create a musty smell, caused by overheated felt undersarking or other insulating material. The stored heat likewise renders the insulation useless, and the heat is radiated back into the lower rooms and spaces in the house.
High Heating/Cooling Costs – With an unventilated attic in winter, room temperatures could drop considerably and you will have to turn up the heat. In summer, room temperatures could rise and you will have to turn up the A/C, or you may be forced to move to cooler environs, especially in hot, humid evenings. Either way, an unventilated attic can mean significantly higher heating or cooling bills.
Destroys Energy Efficiency – Another consequence is that the resulting inefficiency will undermine any efforts to increase your home’s value. You can invest as much as you want in a new HVAC system, energy-efficient windows (which cost anywhere from $8,000 to $24,000), or better insulation, but if the attic remains unventilated, the money you invest in energy-efficient measures will simply go to waste. Note that it will only cost you about $369 to $879 to ventilate your attic.
Allergic Reactions – You may not be aware, but a poorly ventilated attic can indirectly trigger allergies, and in some cases even get into yours or your kids’ lungs, causing an asthma attack. This happens when the air becomes humid during the warmer months, causing condensation in your attic. Since there’s no ventilation, the water droplets don’t dry up, creating the perfect environment in your attic for mold and mildew. As humid air continues to be trapped in your unventilated attic, mold and mildew continue to grow. Mold is present everywhere, and that’s what usually triggers allergies apart from dust or pollen.
The next time you venture into your poorly or unventilated attic, you may accidentally release mold spores and cause them to spread throughout your home, triggering yours or your family members’ allergies or asthma attacks. Should your attic remain insufficiently ventilated and mold is left to grow, you could face steep hospital bills for allergy tests, or pay as much as $3,266 yearly for a family member’s asthma medicine. These costs might have to come out of your pocket, as they aren’t always covered by medical insurance.
Expensive Roof Damage
Apart from letting mold and mildew grow and trigger health issues, an insufficiently-ventilated attic can damage your roof. Without a proper exhaust for hot air and intake for cooler air during summer, the warm air can accumulate in your attic. Roof shingles may become warped or deteriorate from the extreme heat, making your roof unsightly or causing expensive repairs. If your roof becomes warped due to the heat, expect to pay $150 to $400 for minor damage, and $1,000 to $3,000 for major repairs.
During winter, an attic with insufficient ventilation can form ice dams at the bottom edge of the roof shingles. A freeze-thaw cycle ensues, caused by the differences in indoor and outdoor temperatures, which then bend and break the shingles. Ice dams can also put huge stress on the roofing structure. Without proper attic ventilation, minor damage can range from $100 to $300. If the damage becomes serious and requires the entire roof to be replaced, this can cost $4,000 to $20,000 for an entirely new roof.
So how do you fix the situation? First, don’t jump the gun and immediately assume you need a drastic overhaul to your attic, and cram it with ventilation. Check first if your attic is in serious need of ventilation.
How to Know If Your Attic Needs Better Ventilation
While considerable differences between the temperatures inside and outside your home don’t always point to needing a better-ventilated attic, there are other ways to determine this. Here are four ways to determine if your attic is unventilated or if it needs better ventilation:
- Inspect your roof and the eaves. If there aren’t any attic vents on either of them, then you definitely should have some installed. Your roof may already have a ridge vent, which is a continuous air vent that runs along the roof’s peak. If no ridge vent is visible, look for a gable vent. These are louvered openings on the top of roof gables.
- Feel the ceilings. If on a warm, sunny day, your ceilings feel hot to the touch, this means your attic is acting like a solar oven. Without ventilation or with insufficient ventilation, the attic will likely build up heat and cook your roof’s shingles. This will surely raise your cooling bills.
- Inspect the eaves for thick ridges of ice. When winter comes, check your eaves for a buildup of thick ice known as ice dams. They are a sure sign that the ventilation in your attic is either insufficient or nonexistent.
- Check for dampness or frost. In winter, go up to your attic and inspect the beams and supports for dampness or ice formation. The warm air that rises from the lower rooms contains moisture, and it’s bound to condense when it comes in contact with the cooler attic. If the condensation or frost is severe, your attic might not be allowing any air to flow back outside.
How to Determine the Number of Vents You Need
Now that you know your attic lacks the necessary ventilation, how do you determine the number of roof vents your attic needs? First, compute for the square footage of your attic by multiplying its length by its width. For example, if your attic is 40 ft. by 50 ft., its area is 2,000 square feet.
Aim for the ideal of 1 square foot (144 square inches) of ventilation opening for every 150 square feet of the attic. Most building codes only require half that many vents, but the more attic vents you install, the better. If your attic has an area of 2,000 square feet, then 2,000 divided by 150 is 13.3, so you’ll need 6-7 vents (13.33 divided by 2= 6.7) installed onto your roof to ventilate the attic.
To ventilate your attic, it’s best to hire professional insulation contractors in Kansas City. They can better assess the number and size of vents you need to have installed in your attic to maximize the cooling and heating efficiency of your home’s insulation. What’s more, you avoid doing any hard labor or get into any accidents when you hire pros to do the job. They already have the experience, expertise, and equipment to install your attic vents safely and efficiently. All you need to do is sit back and wait for your new vents to be installed.
Did you find this article useful? If your attic needs ventilation or you want to learn more about our other services, contact us today. We look forward to working on your problem and providing you A+ service!