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What Is Air Sealing an Attic? Efficiency & Benefits

Discover the main signs that an attic needs sealing! Drafty rooms and excessive dust represent two tell-tale signs of an air leakage. Air sealing an attic offers several crucial benefits to homeowners, including cleaner indoor air and lower energy bills. But what does air sealing an attic entail? And is it worth it or not?

What Is Attic Air Sealing?

Attic air sealing is one of the best opportunities to save energy in existing homes because attics are easily accessible, serve as a critical interface between conditioned and unconditioned spaces, and contain cracks, holes, and penetrations.

Attic air sealing involves using spray foam, caulk, metal flashing, rigid foam, and weather stripping to plug holes and fill cracks where air might escape. Sealing an attic will improve a home’s comfortability, air quality, and energy efficiency.

4 Signs That Attic Air Sealing Is Needed

Many modern, luxury homes already have air-sealed attics. Those houses that do not have a sealed attic space will begin to show signs. Let’s examine the primary indications that an attic requires airtight sealing.

1. Noticeable Drafts

Feeling a cold draft inside the house represents a tell-tale sign that an attic needs to be air sealed. It often means holes or gaps are spilling warm air into the attic and allowing cold air into the home. In old houses, these air leaks can disturb vermiculite insulation, spreading indoor air pollutants throughout the house, some of which may contain asbestos or carbon monoxide.

Drafts also force heaters and air conditioners to work harder to keep homes comfortable. The unfortunate results involve increased monthly energy bills and more wear and tear on heating and cooling systems.

2. Uneven Heating and Cooling

A homeowner who lives in a house with air leaks in the attic floor will likely experience uneven heating and cooling throughout the house. All the little holes in a home’s ceiling represent potential weak points in its attic insulation. A professional air sealer will check each penetration to ensure it remains sealed around the edges.

Attics also have penetrations in the roof and walls. An air leakage that allows outdoor air to enter the attic can cause uneven heating and cooling from room to room or even within rooms. Some of the most common installations that cause attic air leaks include:

  • Water heater flue pipe
  • Electrical junction boxes
  • Furnace flues
  • Ventilation system
  • Plumbing holes
  • Electrical wires
  • Recessed lights
  • Attic hatch

3. High Utility Bills

An unfortunate sign of an unsealed attic is a high energy bill. As an HVAC system struggles to reach and maintain the desired temperature, it consumes more energy than it would in a home with a sealed attic space. The extra energy consumption leads to an increased energy bill.

When combined with unfaced fiberglass insulation, cellulose insulation, or expanding foam attic insulation, home air sealing reduces monthly energy bills by an average of 15%. Homeowners can expect to recoup their attic sealing investments within 12 months.

4. Excessive Dust

Attics that leak air allow excess dust into the living spaces of a house, spoiling the indoor air quality and impacting the health of everyone inside. Air leaks also permit outdoor allergens, smog, and other particulates to enter the home, which only complicates air-quality issues.

Homeowners who find themselves needing to dust more often than they used to should take it as a sign that their attics need professional inspections. An experienced air sealer will check for holes, cracks, and gaps in the ceiling drywall, attic floor, attic walls, and roof.

4 Reasons to Hire a Professional Attic Sealing Company

Sealing an attic is a big job that requires experience, expertise, and top-quality tools and materials. Amateur air sealing work often leaves behind several leakages and can even damage the home. Find some of the best reasons to hire a professional attic sealing company below.

1. Identification and Sealing of Attic Air Leaks

One of the best reasons to hire an established attic sealing company is prompt identification of air leakages. It’s easy to miss an air leak. Failure to identify an air leakage before sealing an attic will allow cold air to enter a home through the ceiling, causing a draft and decreasing comfort.

Experienced sealers will use the best tools and sealants to create a perfect attic seal. On the attic ceiling, reflective foil insulation will slow heat transfer between the roof and the rest of the attic.

2. Moisture Control

Sealing an attic will prevent moist air condensing on fiberglass insulation. A sealed, dry attic will improve indoor air quality by stopping mold growth and keeping indoor air pollutants out of the living spaces. Sealing an attic may involve installing lightweight aluminum flashing around a penetration created for masonry chimneys.

Aside from mold and mildew, excess moisture can destroy blown insulation and cause wood rot. When hot air and humidity create compressed, dirty insulation, it must be removed and replaced by foam spray insulation or more traditional forms of insulation to prevent dangerous ice dams.

3. Pest Control

Keep wild animals where they belong by sealing the attic. Gaps, cracks, and holes in the roof or exterior and interior walls of the attic can allow rats, mice, raccoons, birds, and insects into the home. Some of these pests make their nests in the cellulose or fiberglass insulation, causing the destruction of the material and creating a mess.

Sealing the attic ceiling, walls, and floor will prohibit ingress and egress for any animal that wishes to make a home using insulation materials. Should a rodent force its way into the attic, the destroyed sealant will provide ample warning to the homeowner.

4. Inspection of Ductwork and Ventilation

A professional air sealer will check ductwork to ensure the HVAC system is filtering dusty air properly. Any holes, tears, or detachments in the ductwork will require repairs before sealing the attic to prevent dust, dirt, and contaminants from entering the living spaces.

Once the attic is air sealed, a professional will check naturally venting combustion appliances to ensure safety and prevent backdrafts. The attic ventilation system will also be checked for blockages, damage, or other defects.

How Much Can a Homeowner Save by Sealing an Attic?

A homeowner can save over 15% per month on utilities by sealing an attic. Depending on the household’s energy consumption, a homeowner can look forward to a full return on investment in one year or less, on average. However, the savings go beyond energy costs.

Everyone who lives in an air-sealed home will also save themselves the frustration and discomfort of a drafty house with poor air quality. They will avoid the cost and inconvenience of replacing rotten joists and rafters in the attic, as well.

An Air-Sealed, Insulated, Ventilated Attic

A sealed attic needs proper insulation to transform a house into an energy-efficient home. Expanding foam, fiberglass insulation, cellulose insulation, and other insulators work hand-in-hand with air sealing to keep living spaces cool in the summer and warm in the winter. Some of the factors to consider when selecting insulation for a house include:

  • Cost
  • Durability
  • Heat resistance (R-value)
  • Pest control
  • Fire resistance

Attic ventilation also plays a crucial role in keeping a house comfortable throughout the year. Ventilation allows warm air to escape the attic and reach the outdoors, cooling the home. It also keeps attic insulation dry, preventing moisture buildup. A professional air sealer will check the insulation to ensure it does not obstruct the natural airflow. Any needed repairs to the ventilation system will be communicated to the homeowner.


Is it good to air seal an attic?

It is good to air seal an attic because a sealed attic will keep warm air inside of your home longer during the winter. It will also keep cool air inside of your home during the summer. A sealed attic will also reduce energy consumption, which results in lower utility bills and substantial savings for your family.

What is air sealing?

Air sealing is the process of closing all holes and gaps with spray foam insulation, which reduces drafts and heat loss by eliminating air leaks around the chimney, plumbing penetrations, and recessed lighting. Other materials used in air sealing may include caulk, metal flashing, weather stripping, or rigid foam.

What are the results of attic air sealing?

The results of attic air sealing are a quieter home, reduced air moisture inside the house, and less dust circulating in the air. Attic air sealing also lessens the risk of ice dam formation. The noise pollution reduction and improved air quality increase the comfortability of a home. The decreased probability of ice dam formation prevents costly roof damage.

How much does it cost to air seal an attic?

The cost to air seal an attic will vary based on the circumstances. Some variables that alter the cost of air sealing an attic include house size, type of materials used, amount of required labor, and the severity of the problem, if any. Contact your local spray foam insulation company to receive a quote. In most cases, homeowners can receive a no-obligation estimate for free.

What Air Sealing an Attic Is | iFoam

Now that you know what air sealing an attic is, think about your own home. Have you noticed the tell-tale signs that your attic should be sealed? If so, our expert team of attic sealers will transform your house into a healthier, more energy-efficient home. Call iFoam at (855) 935-4723 to schedule a free consultation today!