How Much Does Air-Sealing An Attic Cost?

You’ve heard that your attic needs an airtight seal to make your home more comfortable and affordable to live in. But what will something like that cost? Could you air-seal your attic yourself to save some money? Or is it ultimately less costly to hire a professional?

South Central Services has insulated and air-sealed hundreds of buildings. We will always talk about the immense benefits of putting a “lid” on your home via air-seal on the attic floor. Whether you plan to hire a pro or want to try air-sealing yourself, this article will break down costs for you.

What Does It Mean To Air-Seal An Attic?

Attics are notoriously leaky areas of a home. Hot air can flow between the attic and the living space in summer and winter, driving up energy costs. When we recommend air-sealing an attic, we’re talking about identifying all the penetrations in the ceiling that separates your living space from the attic, and sealing them off. Air-sealing cuts off the flow of convection heat in either direction.

You cannot air-seal an attic if you already have insulation installed in your attic without first removing the existing insulation. So, air-sealing an attic means removing any existing insulation and starting with a blank slate.

When air-sealing is done right on your attic floor, it’s arguably one of the least expensive and most impactful parts of an insulation package.

So, what would it cost to get an air-seal in the ceiling separating your living space from the attic?

Professional Air-Sealing Costs

There are two ideal insulation products for attics: blown-in and spray foam. Blown-in insulation is a fibrous material that cannot offer an air-seal on its own. Spray foam, on the other hand, can create an airtight seal when spray-applied to a surface.

If you hire a professional insulation contractor to install spray foam, the cost of air-sealing will be included in the insulation price. However, spray foam may be outside of your budget. In that case, you might hire that professional to install blown-in instead.

In the range of attics we typically work in, the cost of an air-seal ranges between $300 and $1,500. That does not include the cost of the blown-in insulation that is installed after the air-seal. A cost within this range would be shown as a line item on a blown-in insulation quote.

When we are hired to air-seal an attic, that includes any penetration in the attic floor, as well as can light covers.

DIY Air-Sealing Costs

If you want to do your attic insulation DIY, it is possible. A good quality result will depend on the time and effort you invest in the project. However, an attic with an air-seal and blown-in insulation could be installed on your own.

The first thing you’d need to purchase is can foam. Professional contractors purchase commercial-sized canisters, but the same product can be purchased in smaller quantities at Home Depot.

How much can foam you’ll need depends on the size of your attic. By our estimates, you’d need to purchase between 12 and 48 cans of can foam to have sufficient product. This would cost between $50 and $150 in can foam alone.

The cost of can foam isn’t too bad, as long as you can identify all of the penetrations in the attic where air is leaking. The bigger cost of DIY air-sealing is can light covers. Generic can light covers run between $20 and $30 a piece. It is not uncommon to have 30 can lights in a home, which can quickly translate to an additional $500 to $900.

The final consideration we’ll mention is your time. Generally speaking, professionals can air-seal a rather large attic in less than a day. For a homeowner, accessing and addressing the issues in your attic will likely be a much lengthier process.

Remember, Your Attic Needs Both An Air-Seal And Insulation.

All the costs mentioned in this article are strictly for the air-seal in the attic floor. Once your attic is air-sealed and protected from convection heat transfer, it still has to be insulated.

Compared to spray foam insulation, blown-in is the more affordable option. Blown-in could be installed DIY using a rented blower machine. However, our recommendation would be to hire a competent installer. DIY attic insulation is time-consuming. Doing the work yourself may not save as much money as you’re hoping, considering the time you’ll have to invest.

The Bottom Line About The Cost Of Air-Sealing An Attic Floor

The price of air-sealing your attic floor depends on a few factors. The larger your attic, the more expensive the project will be. Hiring a professional could cost anywhere between $300 and $1500, not including the insulation that will need to follow. Doing a DIY project could cost between $400 and $1,100 before insulation. The cost of your DIY work will depend on the size of your attic and how many can lights protrude into your attic floor.

Now that you know how much air-sealing your attic costs, your next step is to:

• Compare attic insulation options
• Estimate the cost of blown-in insulation upstairs
• Decide between a vented and an unvented attic

Disclaimer: While we strive to publish information accurate to building science, local building codes and standards supersede our recommendations.