Insulation Installation: Why Is It Essential?

Insulation is necessary if your home priorities revolve around energy efficiency. If you’re in need of guidance, you’ve come to the right place. Attic insulation, like fiberglass,  shouldn’t be categorized with other DIY projects if you don’t have experience.

Insulation Installation

Fiberglass batts are useful for residential insulation. They help block air gaps that make it difficult for your home to retain heat. used in construction as it has many properties that make life easier and safer for our families. 

How To Install Insulation: Prep

How To Install Insulation: Prep

Fiberglass insulation is the most popular type of insulation and one of the only methods used in residential buildings. Fiberglass is known as “glass wool” because it is made of fine glass fibers. With fiberglass insulation, there are different thicknesses.

The thicker the insulation, the more expensive the material.

Related: The Best Spray Foam Insulation Kit – Most Useful Products For Homeowners and DIYers

Fiberglass is made when molten glass is spun into fibers and coated with a liquid binder. The pieces are torn into even smaller pieces and cooled while dropped onto a conveyor belt, which is then dropped into a pile. 

The piles are pulled through to form a blanket of tangled fibers that will eventually be cut into pieces of fiberglass insulation. Be careful when installing material around your electrical boxes as electricity is a fire hazard. With insulation contact, you don’t want it touching sensitive areas.

Faced Batts Vs Unfaced Batts

Faced Batts Vs Unfaced Batts

Let’s look at the differences between faced and unfaced batts.

Faced Batts Insulation

Commonly known as faced insulation, it has a vapor barrier, or facing, that prevents moisture from moving from one space to another. The facing also helps protect the surface, holds the insulation together, and fastens the material to building components.

Different facing material includes:

  • Vinyl
  • Kraft paper
  • Aluminum foil
  • Foil kraft paper

Unfaced Batts

Unfaced batts are for when you want to install insulation over existing insulation. Unfaced insulation does not have a retarder. Kraft paper insulation includes a paper retarder that prevents mold and mildew. 

Unfaced insulation is ideal for new residential construction and remodel jobs. 

How To Install Fiberglass Insulation

Most of us know what fiberglass insulation is, but do you know why it works so well to regulate temperatures? It slows heat and cold spreading in a building by trapping pockets of air, keeping rooms warm in the winter, and cooler in the summer.

It doesn’t stop air movement completely but will slow it down. The thicker the insulation, the less air movement there will be. Insulation traps air in and doesn’t let outside air inside your home. 


R values measure the effectiveness of how building insulation prevents heat from entering and escaping a home. Higher r values means greater insulation performance.

Choosing The Best Insulation Type 

Types Of Insulation 

Before you can choose the best insulation type, you need to know the their differences. Once you become familiar with the different types, you can separate them according to their R rating. The higher the r value number, the thicker the insulation is and the better it insulates. 

Most homes with 2-by-4 frames need insulation with an r value rating of 13. Those with 2-by-6 frames need insulation with an r value rating of 19. With attic floors, you will need insulation with r value rating of 30 or 40.

Insulation Materials

Fiberglass may be the most popular type of insulation, but it’s not the only one. There are a few other types of insulation that can work just as well. Some are cheaper, others are safer. 

Blow In Insulation

Blown-in insulation fills the gaps between wall studs and ceiling joists. One major concern with this type of insulation is how difficult it is to install.

First, holes are drilled at the top of each stud and material is blown in through a hose. When finished, the hole is sealed with a plug that matches the siding. While the plugs are matched to the siding color, with brick or stucco surfaces, the hole plugs are noticeable.


Cellulose insulation is made from recycled paper products. Borate is also added to make the material fire-resistant. The insulation looks like fluff you’d pull from a mattress and is applied with a hose.

Spray Foam

Spray foam insulation is made from polystyrene, polyisocyanurate, or polyurethane, or in other words, plastic. You can apply spray foam insulation by spraying it on your surface like expanding foam which insulates windows and doors.

Mineral Wool 

Mineral wool insulation is one of two kinds of wool. One is a man-made material made from a combination of natural minerals while the other is a waste product. Both look similar to fiberglass insulation.

Cotton And Straw

Many types of natural materials make for good insulation, like cotton, wool, or straw. Loose fill insulation may not be fire-resistant, but can be with the right treatment.


Believe it or not, but your old denim jeans make for great insulation. You can buy denim insulation, but be prepared to spend more as it’s more expensive than fiberglass insulation. 

Rigid Foam

Rigid foam sheathing is applied to building exteriors. Continuous rigid insulation is a construction method that provides a thermal energy efficient building enclosure.

Meanwhile, polyisocyanurate foam, known as “polyiso,” has the highest R-value per inch of any rigid insulation. This type of rigid foam comes with a reflective foil facing on both sides.

How To Install Insulation: Step By Step

Anyone can install insulation, but they must learn how first. You should always follow the manufacturer’s instructions. The most common materials that insulation comes in are rolls or batts. 


Make sure you take every safety precaution available. Keep your windows open, wear a dust mask, a long sleeve shirt, and pants. You’ll also need to wear gloves and protective eyewear. 

Measure Your Attic Floor

You’ll need the exact measurements of your attic floor before you begin installing fiberglass insulation. With roll insulation, for example, you’ll need the exact square foot of your space so it will be a tight fit when the job is done.

Cutting Insulation 

Professional workman installing thermal insulation layer with fiberglass wool under the roof

Cutting the insulation isn’t difficult. To cut insulation, use a putty knife or drywall knife and press down on the insulation with your other hand. When covering large gaps, the insulation material should fit tightly over the conditioned space, for example.

When working with a crawl space and floor joists, start at one edge of the space and install the insulation between the floor joists.

With your utility knife, move up about 2 or 3 inches. Next, slice all the way down the material. You may need to go over the line a few times to make sure that it is cut all the way through. 

Securing Insulation

You can secure insulation with wire, but it isn’t necessary. Most people prefer to staple insulation to wall studs. Ensure the stapling is done on the sides and not at the ends of the boards.

With kraft paper insulation, the paper acts as an edge you can staple. The paper is a moisture barrier and can protect you from the fiberglass. Make sure you don’t pack the insulation along the eaves of your home. If you do this, it will block the soffit vents and prevent outside air from entering your attic.

You can staple polystyrene attic vents between the roof rafters to make sure your soffit vents are blocked. 

Expanding Foam Touch Ups

After you’ve stapled the insulation, fill in the remaining gaps with expanding foam. You can fill in the areas around your windows and doors, and any areas the insulation won’t cover. 

Covering Insulation 

After you are finished insulating, you can cover the walls. Don’t forget to cut any holes for electrical outlets and switches in both the insulation and the drywall, paneling, or plaster. 

Check out our guide on drywall and plaster. 

Where To Use Insulation 

Where To Insulate 

Now that you know how to install insulation, it’s time to find out where to insulate. 

How To Install Insulation In Attics

This is probably the first place you think of insulating. Attics and ceilings for flat roofs can get frigid in the winter. Insulating them can keep your entire house warmer and cut down on energy bills by a lot. 

How To Install Insulation In Cathedral Ceilings

If you opt-out of an attic for the open ceilings, then you need to insulate them well. If you want exposed beams, you will have to insulate the ceiling you have then create another layer for the new beams. 

Exterior Walls Insulation 

Any wall that has the outdoors on the other side needs to be insulated. This is the number one place that you need to insulate even if you leave everywhere else out. Without this insulation, you won’t stay warm or cool. 

Installing Floor Insulation 

A lot of people don’t know how to install insulation under floors. You can do this as you go or crawl under the house and do it afterward if you forget to while you’re putting down the base of your home. 

Install Basement Insulation 

Not all basements need insulation because concrete is already an insulator. Wood exposed in your basement will need to be insulated, especially the floors of your upper levels which is the ceiling of the basement. 

Install Insulation Around Ductwork 

Insulating ductwork is necessary if you want your central air to do its best work. You will probably need to get a professional that knows how to install insulation for ductwork. But don’t worry, the money will come back to you with this one.

Install Insulation In Dormers

A lot of people forget to insulate part of their dormers. This can cause problems because any area of your house that isn’t insulated can reduce the effectiveness of your insulated home.

Interior Wall Insulation

This won’t help with heating and cooling, but it can be helpful if you want a better sound barrier. Soundproofing a room starts with good insulation.

Wall Cavity Insulation

A wall cavity is a hollow center in a wall. The purpose of a cavity wall is to construct the outer wall of a house. When insulating a cavity wall, it’s best to use rigid foam boards, spray polyurethane foam (SPF), or mineral wool. 

Hiring A Pro To Install Insulation

How To Install Insulation: Step By Step

When you need expert advice, hire a professional who knows how to install insulation. The only downside is cost. So, if you can afford it, then go for it. If you’re on the edge, then ask yourself if you believe that your DIY job will last.

If it will, then do it yourself and save money. It’s always a good thing to learn a new trade. So, embrace the moment! However, there will always be a learning curve when learning how to install insulation. 

Frequently Asked Questions (FAQ)FAQ

What Are The Laws On Insulation Practices?

Each state has separate building codes and standards for home insulation. To learn what the regulations are for your state, visit the North American Insulation Manufacturers Association website for specific information. 

What Is Unfaced Insulation?

Unfaced insulation does not have a vapor retarder, which is paper or plastic facing. 

What Are Unfaced Fiberglass Batts?

Fiberglass batts are made of fiberglass. The insulation is used to prevent heat loss and is available in sheets or rolls. The insulation comes in pre cut batts for standard sized wall sections, and in rolls that can be customized to fit a wall cavity.

The main thing is that you want tight fitting batts that fill the stud cavity so there aren’t any voids or gaps.

What Is A Vapor Retarder Used For?

Vapor retarder reduces water vapor that moves through material. It was formerly known as “vapor barrier.” Retarder refers to the ability of a material to “retard” the diffusion of water vapor measured in units known as “perms,” which is short for permeability.

Is Spray Foam Insulation Good For All Environments?

Spray foam is popular for insulating a home’s foam. Spray foams are better than other types of foam and are good for any environment.

Insulation Installation Conclusion

When considering installing insulation on your attic floor, fiberglass insulation might be your best bet. Attic insulation is easy to install, but it’s best to enlist professional help if you don’t have experience. Whether working with spray foam insulation or loose fill insulation, you want to make sure it’s installed correctly.

You need to be aware of your electrical box, because they do pose a fire hazard. When removing existing insulation from your attic floor, for example, you’ll also need to be aware of your ceiling joists. You don’t want to jeopardize your home’s structure while making it more energy efficient. 

Air gaps are another issue you’ll need to safeguard against, and some insulation materials may not help in this regard. Your attic hatch should also remain protected, and often homeowners will overlook its importance. 

When installing batt insulation, it should fit snugly on your attic floors. As a general rule, during installation, you should wear a dust mask, long sleeved shirt, and long pants. With DIY projects, keep in mind that installing insulation is for those who know what they’re doing. If you’ve never installed residential insulation, then working with fiberglass insulation by yourself is not recommended.