Thinking about adding to or replacing attic insulation but not sure where to begin? It is a daunting idea, isn't it?

Many homeowners want better energy efficiency but don’t want to overspend—or overthink it. The good news: it's easier than you'd think.

If you’re wondering about the average to insulate an attic space, expect anywhere from $1.50 to $5 per square foot, depending on the types of insulation and your method. With some planning, basic tools, and the right material, we know you can handle the job yourself.

1. Get Your Supplies Together

Start by rounding up what you’ll need. “At minimum, you'll need safety gear like gloves, goggles, a mask, and long-sleeved clothing—also a utility knife, a tape measure, and a vacuum or broom," recommends Andrew Legge, CEO of Havelock Wool.

"Additional materials will be necessary depending on your chosen insulation type.” Most of these can be picked up at a local hardware store.

2. Pick the Right Type of Insulation Material

There are a few choices for an attic insulation project, and each one comes with pros and cons. “Choices may include fiberglass, cellulose, mineral wool and sheep's wool," highlights Legge. "Research the performance, cost, and installation difficulties of different materials to determine what will work best in your home.”

“While it is the most accessible and the cheapest option, fiberglass insulation is toxic and low performing over time thus not recommended," he notes.

"Wool insulation, on the other hand, is a good option since it helps in maintaining warmth during the winter and keeping cool during the summer while cleaning up the air inside your home." He adds, "And yes, it is for sure the easiest to work with.”

Here’s a quick comparison to help:

• Fiberglass: Cheap roll insulation is common, but itchy and not great long-term
• Cellulose: Recycled paper, a good blown-in material, better air sealing
• Wool: Fire-resistant, heavier, can be harder to cut
• Sheep’s wool: Safe to handle, regulates moisture, naturally air-purifying

3. Remove Old Insulation (If Needed)

Sometimes you're safe to add a layer of insulation over old material, but if there's any indication that it experienced water damage, or it's just dirty, damaged, or ineffective, it’s worth removing it. “If it is fiberglass or cellulose, carefully remove the old insulation and bag it,” shares Legge. “Wear a respirator and safely discard infected materials. Vacuum any remaining debris.”

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4. Seal Gaps and Cracks

Before adding new or additional insulation, check for proper ventilation. You should manage air flow by checking the ridge vents and stopping the air leaks. “Before installing new insulation, seal gaps and cracks with caulk or spray foam insulation to improve energy efficiency,” notes Legge. Look for spots around ducts, light fixtures, pipes, and the attic hatch.

5. Install the New Insulation

Now you’re ready to lay it down or blow it in. “Lay batts perpendicular to joists or blow in loose-fill insulation with a machine,” highlights Legge. “Make sure not to compress the material in order to achieve even coverage.” For batts or rolls, avoid gaps. For blown-in types, rent a machine from the hardware store and have someone help feed material into it.

6. Check Your Work

Finish up by checking the coverage. “After installation, check for gaps or inconsistencies to maximize efficiency,” Legge adds. A flashlight and ruler can help make sure the depth is even across the attic floor.

FAQs

How much does it cost to blow insulation in an attic?

Blown-in insulation typically runs between $1 to $2 per square foot for materials, and $40 to $70 per hour if you hire someone to do it. And, be sure to ask if the blower machine rental is free—some home improvement stores offer it at no cost to customers when they make a bulk purchase.

How much to replace attic insulation?

Attic insulation costs depend on the type of material and size of your attic. Removing old insulation adds another $1 to $2 per square foot if you're hiring the job out. A full replacement could total between $1,500 and $4,000 for an average home if you go with professional installers. By doing it yourself, you can cut the average cost in half.