What Is the Insulation Installation Process?

Your home’s insulation — up in the attic, in the walls, or down in the crawlspace or basement — can help or hurt your home’s overall energy efficiency and energy bill each month.

No one wants to think about the expense or work of adding new insulation, but if it’s been a long time since you even checked it, it could be necessary. The right type and amount of insulation can help your comfort, energy consumption, and budget. Here’s what you’ll need to do whether you’re tackling the project on your own or hiring a pro.

Preparing for Insulation to Be Installed

You’re having a professional install insulation in your home. That’s probably a smart decision. The Insulation Contractors Association of America says proper installation by a professional insulation contractor helps you get the most benefits from an insulation project. Professionals will handle a job with the best safety, cost efficiency, insurance, and knowledge.

Here’s what you can do to make sure the project gets done affordably, safely, and well.

• Inspect existing insulation: Check the level and condition of the insulation you have in your attic, walls, and/or crawlspace. You want to see where it’s clearly thin, damaged, shifted, or non-existent.
• Roof and exterior repairs: This may require professional work, but fixing leaks or damage to your roof or exterior walls will also stop air leaks, moisture, animal damage, and more from undoing the insulation’s benefits.
• Air sealing: Areas around windows, doors, outlets, vents, pipes, and corners may need sealing with caulk or weatherstripping.
• Moisture control: High humidity can damage or decrease the effectiveness of insulation and make a home uncomfortable. You may need to run a dehumidifier in an area or talk to a pro about putting in a vapor barrier.
• Clear a path to the work site: Even with no DIY ability at all, you can help pros and their crew by making it easy and safe for them to get to and take insulation and tools up or down to where they will work. This may include clearing stairways and making sure lights work where they’re needed.
• Clean the area: If the insulation is going in walls, make sure furniture and other items are moved away from the wall. If the work will be done in the attic, you don’t want to have loads of stuff taking up the whole attic. Clean and declutter the area as much as possible and it will help them out a great deal.

Insulation Installation Process

Installing insulation, especially adding to existing insulation, can be a DIY job. Whether hiring a pro or taking it on yourself, here are the basic steps for attic, wall, and crawlspace projects.

Attic Insulation

1. Choose the type of insulation: Fiberglass, cellulose, and rock wool insulation are the most used materials for attics. Rolls, batts, or loose fill are the most common types. Fiberglass rolls are generally the most DIY-friendly way to go.
2. R-values and math: Find the R-value of insulation recommended for your home, the current thickness, and the depth you need to get to. Energy Star has a general recommendation of R-38 insulation and 10-14 inches of insulation. The more exact answer depends on your climate and geography. To check your zone, see the map below and go to Energy Star’s site for specifics. Then, you’ll need to calculate the space to cover at the right depth. It’s recommended to install two layers, the first between the wood joists in the attic, and the second going over the joists perpendicularly allowing space for air between layers.
3. Remove old insulation: If the current insulation is too worn or has mold or moisture damage, it needs to be removed. Again, this might be the point it’s clearly better to call a pro.
4. Protect the pipes and vents: If you have plumbing pipes in your attic, you don’t want condensation getting on the insulation or the pipes to lose heat, so wrapping the pipes in foam is an important step. Make sure insulation won’t block vents, ducts, or exhausts. You might need to build barriers around fixtures, recessed lights, and vents with sheet metal or wire mesh to keep insulation off of these openings.
5. Improve the airflow: Proper airflow through an attic helps with energy efficiency, temperature, and moisture. If you’re adding insulation in the eaves of the attic, place rafter vents in between the rafters where the ceiling meets the attic floor. Then, you can add insulation in the eaves. If you already have rafter vents, make sure they are clear.
6. Install the insulation: Place one layer of insulation between the joists. Tuck it into corners and along the joist beams without compressing the rolls. The facing should be against the drywall. Cut the insulation as needed. If you’re adding a second layer, it should be unfaced. This means moisture won’t collect between layers. Roll it perpendicular to the joists and the first layer.

Wall insulation

1. Install the insulation: In a framed wall, put rolls of insulation in between and parallel to the stud beams. Cut about one inch larger than the space and tuck it into the sides and corners with no gaps. You don’t want to compress more insulation than this.
2. Staple it: If using faced insulation, pull the paper flange out and staple it, about every eight inches, using a staple gun, along the inside or face of the studs.
3. Insulate any gaps: With unfaced or foam insulation, insulate areas around doors, windows, or other odd shapes.

Crawlspace insulation

1. Lay plastic sheeting: If necessary, lay plastic sheeting along the ground for moisture and pest control. Overlap each plastic sheet by about a foot on all sides, and run it up the walls about six inches. Then tape the sheets to the walls and weigh down the overlapping parts of the sheets with wood beams or rocks.
2. Insulate header, rim, or band joists: These joists are perpendicular to the longer floor joists, forming the outer edges of a floor. You can use roll, spray foam, or foam board insulation to fill these areas.
3. Insulate floor joists: Now fill the larger, longer areas between the floor joists. If using faced insulation, put the paper side up against the subfloor. Cut it so there are no gaps but also no compression.
4. Secure with wire: Install wire about every 12 inches to form a grid to hold the insulation in place. You want the wire against the insulation without compressing it.

Recommendations from Energy Star.

Insulation Costs

The cost of an insulation installation varies widely. Factors include the square footage and depth of the insulation you need, labor costs, and the type of insulation. Additional building material, removing old insulation, repairs needed for issues with frames, vents, fixtures, mold, or water damage, bringing a property up to code, and permit requirements may also add to the cost.

For a crawlspace insulation project the cost ranges from $1,600 to $16,900. The price per square foot for the insulation material can be from $0.30-$4.50. In general, loose fill cellulose or fiberglass insulation is less expensive. Rolls and batts are usually in the mid-range of price. Spray foam, which is usually polyurethane, isocyanate, or polyol resin, is typically most expensive. Labor costs about $40-$80 an hour.

In an attic, the broad range is $1,500-$4,000. Similarly, the wide range of factors includes type of insulation, the amount you need, the square footage of the attic, the prep work needed, removal of old insulation, and labor cost. The cost of insulation ranges from about $1-$7 per square foot. Blown-in insulation and fiberglass rolls are typically less expensive. Spray foam and panel insulation are generally more expensive.

Finding an Insulation Contractor

If you’re hiring a pro, who’s best?

There are general contractors and specialist insulation companies. No matter who you contact, some simple questions and checks can save you money, headaches, and more work down the line.

• Before hiring anyone, look at reviews and ask for references.
• Ask whether the company is licensed and insured.
• An insulation company should thoroughly inspect your home to determine its specific needs. A professional inspection could find there’s more work to be done before or along with the insulation. An inspection should determine the existing insulation level and your home’s needs first-hand.
• Get a written estimate. The estimate and recommendations should make sense based on the inspection, your climate, and your needs, and not seem just like a general estimate.
• Get estimates from more than one company or contractor. It might not necessarily come down to choosing the lowest estimate. You might see more detail or professionalism in one estimate.

DIY Insulation Improvements

You can take on DIY tasks that help insulate your home, save energy and money, and make your home more comfortable without tackling the actual insulation in the crawlspace, walls, or attic.

Eliminate spots air can escape or get into your home. Start with doors that lead outside. If you feel a draft, you can put a down draft excluder, or door snake, at the bottom of the door to plug the gap. This is especially useful with older doors or doors which weren’t custom fit.

Another easy improvement is strategically using window curtains, blinds, and shades. They can be used in the winter to keep more warm air from escaping windows and in the summer to keep the sun from heating up your home.

You can also put up window insulation film. This tight-sealing film reduces heat loss, saving energy and money, especially in cold climates.

You can also weatherstrip and caulk windows, doors, vents, and outlets. Even places with weatherstripping and caulking might need a new strip or touched-up caulk.

You can insulate your water heater tank with a specially-designed blanket to keep heat from escaping. Make sure to follow all safety instructions. You can wrap hot water pipes in foam sleeves. Insulating your water heating system can give you significant energy savings.

Doing an insulation job yourself

Depending on your ability and experience, you can install new insulation yourself. Fiberglass roll insulation is generally the easiest and most economical type for a DIY installation.

The most important aspect of doing this project yourself is doing it safely. Make sure no children, pets, or anyone without protective gear will be in the area you’re working with the old or new insulation. Clean and clear out the area so there are no obstructions or extra hazards. Ventilate and light the area as well as possible.

Make sure you have the right protective gear. This includes wearing long sleeves and long pants, along with socks and tough, closed-toed shoes, preferably boots. You should wear work gloves, eye protection, a head covering, and a respirator mask graded N95 or higher.

When to call a pro

There are many good reasons why calling an expert is often the best call when handling insulation.

You have to handle the insulation with proper equipment and protection. Removing old insulation and dealing with hazardous materials that can be present in older houses can be another scenario.

If you don’t know the type or level of insulation you need for your home and climate zone, it’s better to hire an experienced pro. The same goes for working with spray or blown-in insulation unless you’re experienced with the necessary material and tools.

If you find moisture damage, mold, or other larger problems, it’s unlikely to be a good DIY project.

Hiring a professional will usually be a faster, more efficient resolution to the problem and can turn out to save money overall, especially if you find other problems along the way.

Finally, with a professional and a company, you’re more likely to receive a warranty. A licensed and insured pro will also have knowledge of code and inspection issues.

Benefits of Improving Your Home’s Insulation

You could have one or multiple good reasons to replace or add insulation to your home. If you’re seeing a higher energy bill, the proper amount of insulation might lower it. The Environmental Protection Agency estimates the right type and level of insulation can cut heating and cooling costs by about 15%, or 11% of a total energy bill.

A well-insulated home could be more comfortable, too. New insulation can eliminate drafts and odors if your old insulation was moldy, musty, or smoke-damaged. A well-insulated home will likely heat or cool more evenly.

The right level of insulation can reduce repair bills and add years to your HVAC system’s lifetime by reducing how often it needs to run.

Homeowners can claim federal tax credits for new insulation. With the 2022 Inflation Reduction Act, specifically the Energy Efficient Home Improvement Credit, you can claim 30% the cost of new insulation — up to $1,200 each year — until the end of 2032, unless the program is changed or extended.

For more information on tax incentives, visit the IRS site on the credit program. You can also explore state and local incentives at the Database of State Incentives for Renewables & Efficiency (DSIRE).

If you’re looking into more ways to improve the energy efficiency of your home, you can visit Palmetto’s solar savings calculator or contact us.

Frequently Asked Questions

Does the type of insulation matter?

Yes, the right type of insulation depends on where it’s going in a house, its R-value, if it should be water resistant or fire retardant, and if the expense is worth it for the given job. A professional can work with you and find the right solution.

Can a house have too much insulation?

Yes, a home can be over-insulated. When insulation is in the wrong place, like over the soffit vents in an attic, it can trap air and hurt the healthy airflow in a building. That can lead to too much humidity, ineffective temperature control, and higher energy usage overall.

Where’s the most heat (energy) lost in a house?

Heat rises. So the attic and windows on upper floors are where the most heat can escape a home. All doors, windows, and vents can have gaps where warm or cool air can be lost. 

Disclaimer: This content is for educational purposes only. Palmetto does not provide tax, legal, or accounting advice. Please consult your own tax, legal, and accounting advisors.

About the AuthorAndrew GiermakWriter and Editor

Andrew joined Palmetto in Charlotte in August 2024. He’s been a writer in journalism, then in business, going back to almost the 20th century. He’s lived in Indiana, Virginia, Pennsylvania, Virginia again, and now North Carolina for the last 12 years. He likes golf. Is he good at it? Not so much.