Indianapolis experiences extreme weather—from sweltering summers to icy winters—that can strain your comfort and energy use. Without proper insulation, your home may struggle to stay at a consistent temperature, and this will lead to higher utility bills and discomfort. Some sources claim that if you must choose only one, roof insulation is more important than wall insulation. While both are vital, roof insulation plays a more direct role in temperature regulation, as it has the most impact on the energy efficiency of your home.
About Heat Transfer
First, it helps to understand heat transfer, which is the process by which thermal energy moves from warmer areas to cooler ones. What we often refer to as “heat loss” is really just heat shifting to a colder space, as energy naturally flows from high to low temperatures to reach equilibrium.
Heat transfer is what makes your home seem too cold in winter and too hot in summer. The thermal energy is just moving in different directions. Heat transfer can occur in a number of ways, but the relevant methods here are conduction and convection. Conduction is when the energy transfers via touch or connection. The hot air outside touches the exterior of your house, transferring some energy and thus heat to the structure. That warms the surrounding air inside your home.
Convection is when the energy transfers via the movement of gas or liquid. The air that was next to the heated wall picks up that energy and flows into the room, displacing cooler air. That cooler air can even end up next to a hotter wall and pick up thermal energy, perpetuating the cycle and warming up the room. (The third method is radiation, in case you were curious.)
The Role Roofs Play in Heat Transfer
Warm air naturally rises while cooler air settles below, which can be helpful in summer—especially when ceiling fans or air vents push cool air downward. However, if your roof isn’t well insulated, the rising warm air collects near the ceiling and remains trapped, since the roof and outside air are already hot.
In winter, the problem intensifies: warm air rises and meets the cold roof, which will transfer heat through the ceiling and out of the home. This loss of thermal energy leads to a colder interior and will place a greater demand on your heating system.
According to the U.S. Department of Energy, up to 25% of heat loss occurs through the roof when it is not properly insulated. In colder regions, this percentage can be even higher. Homes without adequate attic or roof insulation may spend 15% to 20% more on heating during the winter months. But the good news is that investing in proper insulation can significantly reduce this loss and improve overall energy efficiency.
How Insulation Stops Heat Transfer
Insulation acts as a barrier that stops much of the thermal energy from flowing out. Insulating materials aren’t good at conducting energy, which means that when hot air hits the roof in summer, for example, much of the thermal energy that transfers to the surface of the roof doesn’t make it through the layer of insulation. That protects the air inside the home because the ceiling material stays cooler, and any air molecules touching it don’t pick up all that thermal energy. The better the insulation, the more it blocks heat transfer.
When choosing insulation for your roof, choose materials that have a high R-value, or resistance to heat flow. Spray foam insulation is very useful since it can expand to plug up holes and create an air-tight barrier. Fiberglass is a cheaper option and still offers good thermal protection when properly installed. Blown-in cellulose is great for a home that has an attic, as it will fill all of the nooks and crannies. You may feel confused about which one to choose, so you’ll want to consult a professional to figure out what is right for your circumstances.
Why Insulating the Roof Is More Critical Than Insulating the Walls
Clearly, insulating the roof is important. But you may ask the question: “Why isn’t insulating the walls as important, especially if I live in a multistory home with a lot of wall surface area?”
While the walls can also be subject to thermal transfer, the effect isn’t as pronounced because that warm air is rising instead of spreading out sideways. So, the majority of the thermal energy heads to the roof rather than the walls that are lower down. However, if you can insulate both the roof and the walls, do so. You’ll only make your home more energy-efficient.
What Happens to Your Household’s Energy Use When the Roof Is Properly Insulated
Installing home insulation can prevent thermal transfer and help your heating and cooling systems to regulate your indoor temperature easily. And if less energy is lost through the roof, your heater or air conditioner has less work to do, which can result in less energy used overall. This means you’ll probably start seeing lower utility bills. Savings aren’t guaranteed (since energy use depends on the weather), but the more insulation you add, the better the chances are that you will save significantly on energy bills.
Signs You Need Roof Insulation
If you notice the internal temperature of your home changing drastically or maybe not cooling or heating as well as it should, that’s a sign that heat transfer is letting hot air go where it shouldn’t. Another sign is that you’ve noticed drafts, which indicate that air is getting into the home via small gaps somewhere. In winter, if you see ice dams forming on the roof along with icicles, you need to have roof insulation installed as soon as possible.
Once you do have the insulation installed, if you still have issues with inconsistent temperatures or drafts, that’s when you want to start considering wall insulation.
Signs Something Is Wrong With Your Current Roof Insulation
If you thought you already had roof insulation but have noticed that the temperature is less consistent, that could be a sign that the insulation has broken down. You may also see your monthly energy bills go up even when you haven’t consciously been using more energy and rates have stayed the same. Ice dams can indicate that the insulation is in need of replacement, too; when warm air from your home leaks out, it can melt snow that’s on your roof. The melted snow refreezes in the cold air, forming ice. Snow that melts after it stays pooled behind the ice will eventually lead to a roof leak. So if you see signs of that, it’s time to have the roof insulation replaced.
By the way, if you see evidence of a pest infestation in your attic or upper crawlspace, have the insulation inspected. The pests, be they bugs or animals, may have torn up the existing insulation to make nests or tunnels. Age can also make the insulation break down, as can exposure to moisture from a roof leak.
Call the Experts for Help
If adding or replacing roof insulation is something that you want to do, the team at Red Bird Roofing can help. We have been serving clients in the Indianapolis region for a considerable amount of time now with our roofing services, and we are known for our outstanding work ethic. Give us a call today for help with your insulation.
