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What Is The Best Insulation for Walls?

Malcolm Tatum
Malcolm Tatum
Malcolm Tatum
Malcolm Tatum

Wall insulation is any type of insulating material that is attached to or placed within walls. Normally, the main function of wall insulation is to increase the climate efficiency of the space by making it easier to heat and cool the room. Depending on the type of wall insulation used, the product may also help to soundproof the space and minimize the amount of noise that enters or escapes from the room.

Various types of insulating products are used for proper wall insulation. When the task is to insulate walls in a home that is under construction, it is not unusual to use rolls of fiberglass insulation that can be cut to the right lengths and tacked to the interior area between each side of a finished wall. In this application, the cut sections of insulation are secured in place before closing up the wall. The result is interior walls that minimize sound transference between rooms and exterior walls that effectively block the entry of outside heat in summer months while also preventing cold from entering the home during winter months.

A roll of mineral wool insulation.
A roll of mineral wool insulation.

When installing insulation in older homes, rolled insulation may not be the most viable option. However, there are a couple of other options for wall insulation that are worth consideration. One is the use of foam insulation. The foam is blown in to the walls, often from the attic area. As the foam enters the open space between wall facings, it expands and effectively fills in the open area.

Foam insulation can be sprayed to fill the spaces in walls.
Foam insulation can be sprayed to fill the spaces in walls.

A second wall insulation option for older homes is the use of insulating chips. As in the case of foam insulation, machinery is used to blow in the chips and fill the open spaces within the walls. While the chips do not expand like the foam, they can easily fill the space and create an effective barrier than makes heating and cooling interior rooms a much more energy efficient task.

Soundproof drywall may be used in radio stations and recording studios to dampen sound.
Soundproof drywall may be used in radio stations and recording studios to dampen sound.

An insulated wall provides a number of benefits for the occupant of the building. Wall insulation makes it easier to heat and cool the space and save money on power bills. Depending on the type of insulation used, there may also be a significant reduction in noise within the space, since many types of wall insulation have soundproofing qualities. The insulation may also help to seal tiny cracks where the house has settled and the joints are no longer in perfect alignment.

Installing wall insulation is not a task limited to professionals. Homeowners may choose to handle the job of insulating the home themselves. However, it is a good idea to consult a professional in order to choose insulation products that are right for building type, and will take into consideration of factors such as humidity control and soundproofing if those are issues of importance to the owner.

How To Install Insulation in Walls

Insulating the walls of a home should be taken into consideration at the beginning of the construction or remodeling process. Making sure that everything is done correctly can avoid the hassle of any future complications.

Check for Oversights

Insulated walls are only as effective as the foundation that supports them. Homeowners and professionals should check for any air gaps that exist in areas that could be easily overlooked. Spray foam can be used to seal openings around pipes, and high-temperature caulk can encase electrical outlets.

Get the Correct Dimensions

Insulation should be tightly packed between joists. Before filling in an area, it is important to properly calculate the length, width and depth. Adjustments may need to be made to accommodate any existing pipes or wires. Walls should be scraped clean of any prior substances or materials to get accurate results.

Choose Materials Wisely

Builders and homeowners naturally want the best results at the lowest cost. Fiberglass insulation is on the cheaper end of the spectrum and is less of an irritant to those that come into contact with it. Cellulose may be the better option if fire safety is a major concern in the home due to extenuating circumstances.

Put in Place

Lay the padded insulation over the desired area and staple it into place. Some areas may require a second roll to create a thicker level of protection. Use spray foam to fill open areas if this product is more desirable. Once all these steps have been completed, drywall can start to go up.

How To Blow Insulation Into Wall

Traditional insulation typically comes in batts or rolls. Builders can either order industry-standard sizes or choose to individually cut materials from long sheets. However, appropriate sizing can pose a problem when working with areas with limited accessibility. If visibility is low or it is difficult to enter an area, it may be harder to gather accurate measurements to properly install the materials. Even the slightest miscalculation can result in gaps permitting air to flow through the protective barrier.

Rather than the well-known pink filler, another option is the use of spray polyurethane foam. The interaction between certain chemicals creates a plastic foam that can be applied as a spray and serves as an effective form of insulation. Trained professionals use a special device to blow the substance into all open spaces and areas of concern. The spray expands and tightly wedges itself into place. Excess foam is then scraped away to allow for a smooth finish.

Spray foam is a great way to save energy. Its ability to expand increases the likelihood of successfully filling any cracks or holes that may allow air to flow in or out of the home. With better insulation, a house is less dependent on the need for air conditioning or heating systems to regulate the temperature during months with extreme weather conditions. However, it should be noted that blowing in insulation is often more expensive and can create safety hazards during the installation process.

How To Insulate a House With Existing Walls

Insulating a home once all the walls have been constructed is more difficult. Laying out insulation in the empty cavities between joists is no longer an option as visibility and access is hindered by the drywall. Ripping out these structures to place the insulation may seem like the most logical option, but it often comes at a hefty cost. Figuring out a workaround for this situation can save time, money and resources.

It is easier to patch up a few holes here and there than it is to rebuild an existing wall. Cutting small holes between joists near the top of a wall can serve as a point of entry to insert insulation.

Commonly Used Materials

Cellulose insulation, made from recycled newspaper, can be blown inside a wall at high speed. As the material gravitates towards the bottom of the cavity, the space between the wall gradually becomes denser and provides additional thermal resistance. This process can be repeated over time to areas that have been retrofitted with the same material, further filling in the spaces.

Alternatively, liquid spray foam can be slowly poured into the entry holes. Once the liquid reaches the farthest point of the enclosed area, it begins to expand. Eventually the foam hardens and creates a barrier against incoming or outgoing airflow. This technique is like that of spraying in polyurethane foam but can be used to fill in already-closed walls.

Malcolm Tatum
Malcolm Tatum

After many years in the teleconferencing industry, Michael decided to embrace his passion for trivia, research, and writing by becoming a full-time freelance writer. Since then, he has contributed articles to a variety of print and online publications, including HomeQuestionsAnswered, and his work has also appeared in poetry collections, devotional anthologies, and several newspapers. Malcolm’s other interests include collecting vinyl records, minor league baseball, and cycling.

Learn more...
Malcolm Tatum
Malcolm Tatum

After many years in the teleconferencing industry, Michael decided to embrace his passion for trivia, research, and writing by becoming a full-time freelance writer. Since then, he has contributed articles to a variety of print and online publications, including HomeQuestionsAnswered, and his work has also appeared in poetry collections, devotional anthologies, and several newspapers. Malcolm’s other interests include collecting vinyl records, minor league baseball, and cycling.

Learn more...

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    • A roll of mineral wool insulation.
      By: brozova
      A roll of mineral wool insulation.
    • Foam insulation can be sprayed to fill the spaces in walls.
      By: auremar
      Foam insulation can be sprayed to fill the spaces in walls.
    • Soundproof drywall may be used in radio stations and recording studios to dampen sound.
      By: imkenneth
      Soundproof drywall may be used in radio stations and recording studios to dampen sound.