How to Cool an Attic Properly

Every summer, homeowners face the same dilemma of keeping their homes cool without breaking the bank on their energy bills, with the average energy bill totaling about $137 a month.

Many homeowners don’t know that their attics can be a big culprit in wasting energy.

Heat often collects in the attic from the roof and radiates into the lower living spaces. This forces homeowners to crank up the AC, raising energy bills. So, what can you do?

Luckily, there are several ways homeowners can cool their attics and make their homes more energy-efficient. You can finally cool your attic the right way through air sealing, insulation, or ventilation.

Air Seal

One of the easiest and best ways to help cool down a hot attic is with proper air sealing. This is particularly effective when used in tandem with insulation and other strategies.

What is Air Sealing?

Air sealing is finding and closing air leakage points in and around your home. This is usually your attic walls, floors, entrances, and spots in between ventilation units. These pockets of air leakage can be big or small, accounting for over 40% of all energy lost in your home.

For more information on attic air sealing, including cost savings, check out our guide: Is Air Sealing the Attic Worth It?

How Air Sealing Cools Your Attic

By properly air sealing your attic, you’ll prevent cool air generated by your AC units from escaping to your attic. It’ll also prevent heat and warm air in the attic from radiating down into the lower levels.

It also prevents the formation of ice dams on your roofs in the winter. This is relevant in the summer because ice dams can cause moisture buildup, damaging your attic insulation. If your insulation is weak or insufficient, your attic will allow more heat to transfer into your home in the hot summer months.

How to Air Seal Your Attic

Before You Start

If you can, obtain or create a sketch of your attic. This will help you pinpoint areas of air leakage. Pay close attention to areas like dropped soffits over kitchen cabinets, slanted ceilings over stairways, areas where the walls and ceilings meet, and other dropped-ceiling areas.

See where your attic is leaking air. Schedule a free attic inspection.

Wiring holes, gaps near plumbing and pipes, and recessed lights are also common areas for attic air leakage. Write down these spots and ensure you have the right equipment to seal them.

Alternatively, we recommend getting a professional attic inspection completed by a licensed contractor. This will provide you with detailed insights, including thermal images of your attic. Use an attic inspector’s experience and professional equipment to pinpoint the exact spots where unwanted heat transfer is taking place.

Air Sealing the Attic

Start by filling in the big holes. You can do this by wrapping insulation in plastic bags and plugging areas like open stud cavities, ensuring it fits tightly.

For dropped soffits, remove the insulation and add a piece of reflective foil or rigid foam board a few inches longer than the opening. Seal it in place using caulk or other adhesives.

For pipes that have small air pockets, use caulk or foam to fill the space around them. Make sure you seal the attic hatch with new wood stops and adhesive foam weather strips.

Add Insulation

Insulation is usually the most common method of cooling your attic and preventing the heat from transferring downstairs. It prevents heat from radiating downwards while keeping cool air from escaping to the attic.

What is Attic Insulation?

Attic insulation creates barriers between the roof and your attic and the attic floor to the rest of the home. It comes in various materials, including fiberglass, cellulose, and even reflective surfaces similar to foil.

How Insulation Cools Your Attic

Insulation keeps the sun’s heat from radiating into the lower floors, meaning your home will be noticeably cooler. This means your AC won’t have to work quite as hard to maintain a cool internal temperature.

Insulation also prevents cool air from downstairs from escaping into the stuffy attic since it reduces the movement of air. The EPA estimates that you can save over 15% on your annual energy bills by adding insulation to your attics and other areas.

How to Apply Attic Insulation

Before You Start

Always check your local building code’s recommended R-values or your insulation’s ability to reduce conductive heat flow. It’s also recommended that you seal any air holes prior to installing insulation.

Take note of areas in your attic with plumbing, ductwork, and wiring. For your own safety, make sure there aren’t any cracks in your attic’s foundation.

If you’re applying rolled-up batts or reflective insulation, make all the necessary measurements, so your insulation fits properly. Purchase safety goggles and masks since materials like fiberglass can be dangerous to your lungs and eyes.

Insulating an Attic

If you’re using batt or roll insulation, target areas like your skylights and cut out the necessary amount of insulation. You can secure it between the framings with staples and house wrap.

Get an attic insulation estimate. Schedule a free attic inspection.

Make sure not to compress the insulation, or it’ll become less effective. Whether it’s the stud walls or the joists, make sure you gently fit the insulation without leaving any gaps.

If you’re using blown-in insulation, plug in the machine and feed half a bag of insulation into it. Turn the machine on and fill any areas that need insulation. Be careful not to spray the loose fill in the rafter vents.

Reflective insulation requires you to measure the surface area of the places you’re covering and staple the material to the wood.

Add Ventilation

Ventilation allows your home to breathe. In the attic, it pulls fresh air through it and lets the heat escape regularly. Let’s explore how attic ventilation works to cool down your home.

What is Attic Ventilation?

A balanced ventilation system occurs when the amount of air entering the attic equals the amount leaving it. The cooler air from the intake vents pushes the warm air up and out through the exhaust vents near the ridge.

Without proper intake ventilation, the exhaust vents don’t work, and the heat doesn’t have a way to escape. This can cause permanent damage to your roof, which, as we discussed, can damage your attic insulation and affect your home temperature.

How Attic Ventilation Cools Your Home

In the summer, an improperly vented attic can cause many problems. Without proper ventilation, the heat in your attic has nowhere to go. This means your upstairs rooms will be uncomfortably hot until the sun goes down.

As such, poor ventilation causes hotter attics. This means hotter upstairs rooms and more stress on your AC units. By installing proper ventilation and letting the air circulate in and out of your attic, less heat will be trapped.

How to Ventilate Your Attic

Before You Start

First, look for signs of poor ventilation by either looking at your home yourself or calling a contractor. These signs include:

• Curling shingles
• Roof damage
• Excessive attic heat
• High summer energy bills
• Rust on metal components in the attic

Keep in mind that every attic has different ventilation needs. Calculate the right amount of ventilation for your attic beforehand. There are a few different equations you can use to determine this number.

Ventilating an Attic

Generally speaking, installing attic ventilation isn’t a DIY project. You should call a trusted professional to install the different types of attic ventilation common in most homes.

There are several different types of attic vents that you can use to improve the air circulation in your attic. These include turbine vents that can remove over 300 cubic feet of air a minute.

Active, power vents are smaller vents that can pull hot air out of the attic using electricity or solar power. Passive vents, such as box vents or ridge vents, can use natural winds and convection to move air through your attic.

Lower Your Energy Bills With Cooler Attics

Your attic is a literal hotspot for summer heat, but that doesn’t mean you have to break the bank trying to pay your energy bills. Leverage the three different strategies in this article to create a much more energy-efficient attic today.