How much does it cost to add blown insulation to an attic?

Author: Wilhelm Renner  |  Last update: Monday, May 12, 2025

The cost to blow insulation in an attic typically ranges from $1,000 to $2,700, depending on factors such as the size of the attic, type of insulation material, and desired R-value or insulation thickness.

How much does it cost to get insulation blown into an attic?

Existing walls: Replacing insulation in an older house costs around $1.75 to $3.50 per square foot. New homes: Insulating attic walls in a newly constructed home with blown-in insulation costs $2 to $4 per square foot. Attic: Insulating an attic using blown-in insulation costs between $3 to $7.50 per square foot.

Is blown-in attic insulation worth it?

  • Energy Efficiency: Blown-in insulation can significantly reduce heat loss in winter and heat gain in summer, leading to lower energy bills.
  • Coverage: It can fill gaps and voids better than batts or rolls, making it effective for irregularly shaped spaces, around ducts, and in attics.

How deep should blown-in insulation be in an attic?

Insulation levels are specified by R-Value. R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

Can you put too much blown insulation in your attic?

Mold and Mildew Growth

Having too much insulation in your attic can allow for the accumulation of moisture. This leads to mold and mildew growth, which can be extremely bad for your health.

Things To Know Before Insulating Your Attic | Improve Comfort

What time of year is insulation cheapest?

Best Time of Year to Buy Insulation

In this case, the spring is the best time, because you will also start to see savings in the summer months. The same is true for warmer climates, just different times of year because you'll want the job finished before the heat sets in.

What is better blown-in insulation or rolls?

Blown fiberglass insulation scores an R-value of 3.2 to 3.8, making it slightly less likely than rolled fiberglass to prevent the flow of heat into and out of your house. That being said, though, blown fiberglass insulation isn't meant to cover huge areas like rolled fiberglass insulation.

Does Lowes install insulation?

Lowe's is here to help with our blown-in and batt insulation installation service. There are two types of insulation material to choose from, and which one you choose is up to you. Cellulose insulation, made from recycled paper and treated to be fire-resistant, is the most common material used.

How much does it cost to finish a 500 sq ft attic?

Finishing an attic generally costs between $30 and $60 per square foot, including labor and materials. This gives you an average overall cost of $4,000 to $16,000 for the standard sized attic. Of course, the cost depends on how big your attic is and what type of finish you want.

How often should attic insulation be replaced?

However, due to its construction with natural materials, eventually the product will lose effectiveness. Fiberglass insulation typically needs to be replaced 15-20 years into it's life, as it can easily become dirty, wet, moldy, and ineffective if there's a roof leak or water damage of any kind.

How long does it take to install blown-in insulation in attic?

How long does it take to install blow-in insulation? Most residential projects take around one day to install, depending on the size of the building.

Do you have to remove old insulation before installing new?

Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.

What type of attic insulation is best?

Fiberglass batt is considered to be the best insulation for attics. Compared to other insulation materials, it is the cheapest and easiest to install. Fiberglass batt is also incredibly energy efficient, as it helps to slow the spread of hot and cold air.

Should I replace 20 year old insulation?

However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.

What is the most affordable insulation?

Fibreglass insulation is one of the most affordable insulation materials available on the market, with the only real competition in terms of cost being expanded polystyrene (EPS) insulation, commonly known as Styrofoam.

What are the disadvantages of blown-in insulation?

Cons of Blown-In Attic Insulation:

Poor installation can lead to uneven coverage, material waste, and even structural issues like sagging ceilings. Hiring a skilled installer is crucial to getting the most out of this insulation type.

Where should you not put insulation in the attic?

Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).

Is it okay to cover attic insulation with plywood?

Can I put plywood over insulation in the attic? Yes you can install plywood subflooring directly over the floor joists and insulation on your floor. You need to install rigid insulation boards on top of the attic flooring joists and then install plywood over the top.

What is the labor cost to install insulation?

Most installers charge between $40 and $80 per hour to install insulation, so the more complex the project, the more it will cost. A few complexities that may increase the cost of labor include: Your installer needs to install insulation in hard-to-reach areas.

How much blown-in insulation do I need for 1000 sq ft?

For example, if the square footage of the room you're planning on insulating is 1,000 square feet and you want to achieve an R-value of 60, you will need approximately 17 bags to fully insulate your room. If you are using loose fill insulation, the coverage varies based on the R value that is needed.

Previous article
Can I change the size of my garage door?
Next article
What are the negatives of Dekton?