What R-Value Insulation For Interior Walls - InsulationProTalk.com (2023)

How to choose the right insulation R

Wall insulation: what R-value should I install?


A common question asked by many homeowners undertaking a DIY insulation project is what R-value should I use? The answer is quite simple once you know some facts. Let's go through the simple steps. Then you can use thatinsulation calculatorto determine what insulation you need for your project.

What about the interfloor and interior wall insulation?

The roof and walls are where the greatest heat losses and gains occur in a home. For optimal energy efficiency, you should also consider insulating the interior walls, floors, and mezzanines of multi-story homes.

The ideal R-value for underfloor insulation depends on the climate of your location and the layout of your home. We typically recommend at least R2.0 and upgrading to R2.5 for cooler locations like Hobart, Melbourne and Adelaide.

With thermal insulation on the interior walls of your house, you create climate zones for more energy-efficient heating and cooling. In addition, the installation of R2.5 soundproofing on the interior walls and between floors helps create a quieter home.

You can also install roof insulation of R4.0 or higher between floors. These blocks are thick enough to help stop sound transmission and improve your home's thermal performance. Knauf Earthwool recently launched a new onesound insulationProduct with R4.0 thermal classification, absolutely perfect for this application.

Advantages of insulating interior walls

The best way to answer the question of whether you need to insulate interior walls is to list the advantages of the process.

first of all,internal insulationoffers sound deadening benefits. Adding insulation reduces noise and sound transmission from one room to another. Sound also penetrates through the wood structure, so the insulation is not a complete sound barrier. However, the noise is greatly reduced.

The internal insulation also ensures energy savings. If you have rooms that are not used all year round, internal insulation saves a lot on energy costs. Some spaces that are suitable for interior insulation include unused spaces, storage rooms, and tri-season rooms.

The insulation inside reduces the heat transfer that occurs due to unused spaces. So if you have unused spaces, the answer to the question of whether you need to insulate interior walls is yes. In areas with extreme temperature fluctuations, it does not help to simply close unused rooms.

In the case of partition walls, the insulation of the inner walls is essential. These are walls that separate the individual living spaces in apartments and maisonettes. you absolutely needReduce sound and heat transmission.

Imagine that nobody lives in the apartment that is connected to you by a partition? Since this apartment has no heating, it steals all the heat from your apartment.

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Effective and quick installation

While the beauty of choosing InSoFast modules becomes apparent when you consider the maximum energy efficiency they allow, you should also consider the great comfort factor that comes with the product. The design is such that all you need is a saw, Loctite glue, concrete fasteners, a utility knife and spray foam. In a short time you can finish the entire basement insulation.

From setup to cleanup, InSoFast is easy and lives up to its In So Fast name. Line up the panels, making sure they fit properly and remember to apply glue to the knobbed areas of the panel. The construction is such that minimal measuring and cutting is required.

Just like Legos, this product adapts with minor adjustments and any insulation project is easy. Finally, put some spray foam in the small gaps and along the seams, let it harden and then remove it with a razor blade. Use some antistatic spray for cleaning. The foam particles lose their natural stickiness, making it easier for you to vacuum or sweep them.

ConPanels InSoFastfind the most cost effective and convenient way to add good R-value to your basement insulation.

Various spaces: attached garages and more

What R-Value Insulation For Interior Walls - InsulationProTalk.com (1)

Figure 7-10 Stands can be hung on studs and nailed to the existing wall

Heat moves in all directions, so walls and floors must be insulated where they separate a heated space from an unheated space. This is often found in bonus rooms where living space is created above an attached garage.

Attached unheated garage

The walls, roof, and adjacent door to the home should be insulated and airtight to reduce heat loss and prevent garage exhaust fumes from entering the home. See Part 7.1, Blown Insulation and Part 7.2, Interior Renovation, for wall insulation instructions if the garage is above ground, or Section 6, Basement Insulation if it is underground.

If the garage roof is open and the joists are visible, proceed as described for an open foundation. It's best to remove an existing garage ceiling panel to properly seal and insulate it.

If the garage has a finished ceiling, a contractor can blow a pack of dense insulation into the space between it and the floor above. Any holes cut in the ceiling will need to be carefully resealed to prevent exhaust fumes from the garage seeping into the rooms above, and all ducts in the house need to be sealed with an approved sealant.

Figure 7-11 Airtightness and insulation between an unheated garage and the house

Also read:What is the best insulation?

If you get it done professionally

You need to get quotes from different contractors for a set R-value. Be sure to describe the job in writing using the same terms for each. You can also ask any contractor about their airtightness services. Remember you want quality materials and workmanship and a good price. Don't be surprised if quoted prices for a given R-value facility vary by more than a factor of two. When you talk to a contractor, talk about R-values. Remember that R-values ​​are determined by material type, thickness, and installed weight per square foot, not just thickness.


in the unfinishedAttic floors, work from the perimeter toward the attic door. Be careful where you step in the attic. Only walk on the joist so you don't fall through the drywall. You may need to put running boards on the joists to make the job easier. Remember that before you insulate your attic, it is important to seal any air leaks between your living space and the attic.

In some homes, it is easier to achieve full attic coverage with blow-in insulation. It is best to hire an insulation company for this. Loose fill insulation must be prevented from entering ventilation openings or coming into contact with heat-generating equipment. Cordon off these areas with baffles or brackets to hold the loose-fill insulation in place.


basement walls

How do I decide where to insulate my old house?

The most accurate way to find out is to conduct an energy audit of your home. This test usually involves a thermal imaging gun and a blown door, and will identify where your home is leaking and poorly insulated. For most homes, the attic or basement is the best place to start insulating. But with the thermal imaging camera, you can uncover entire wall sections with no insulation or spots where old insulation has separated.

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What is insulation R?

Insulation ratings are measured in R-values ​​per inch of thickness. An R-value tells you how well a type of insulation can prevent heat from entering or leaving your home. Insulation R-values ​​vary depending on the type, thickness and density of the insulating material. Typically, a higher insulation class R means better climate control and better energy efficiency for your home. A higher insulation R-value usually means a higher price.

For each type and material of insulation, check the manufacturer's R-value per inch of thickness. In general, the insulation installation method can give you an idea of ​​how it compares to other types of insulation.

Here are the installation methods from lowest to highest average R-value per inch:

  • blown insulation
  • insulating blankets
  • spray foam insulation

Remember that the material from which the insulation is made also changes the R-value.

Tip: Radiation barriers and vapor barriers are not rated for R-values.

What are rigid foam boards?

Complete ProPink® Blown Wall System - Learn why contractors prefer blown walls

Rigid foam panels are large panels of expanded polystyrene foam. The leaves, found at most home centers, are 4 feet by 8 feet. Typical thicknesses range from 1/2 inch to 2 inch and impart R values ​​from R-2 to R-10. Most leaves are marked vertically. This way you can break sections of the foam board instead of cutting it.

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What type of insulation should I use for interior walls?

What works best depends on the application and it takes a little research to find the best solution for your home.

  • foam boardsInsulation are better insulators than the alternatives, so they are thinner and take up less area. They may also include a vapor barrier. But they're more expensive and may not tick the breathability boxes on your checklist.
  • mineral woolsuch as Rockwool or Knauf are widely used. These are usually available as wadding or semi-rigid duvets.
  • natural materialssuch as sheep's wool, wood fiber insulation or cork are good options for those looking for a high level of breathability and are interested in a product's eco-friendly properties. Even natural materials do not outgas.
  • fine insulation:It is the voids, the exposures and the returns of the floor that require special attention to ensure the continuity of the insulation and eliminate thermal bridges. Thinner materials are typically required here and a choice of colors is available from Therma-Coat Acrylic Insulating Primer to Aerogels such as Spacetherm.

Installation costs soundproofing

Soundproofing is a type of building material used for soundproofingclosed spaces. The soundproofing process creates a barrier between indoors and outdoors, reducing noise and unwanted reverberation. Population growth and cramped living conditions have led to an increasing demand for soundproof environments. The cost of installing soundproofing may discourage some potential buyers from investing in it.

Soundproof paint is another option that can reduce noise. This water-based paint contains ceramic microspheres, sound-absorbing fibers, and thermals, or tiny vacuums filled with pigment. Soundproofing paint costs between $40 and $100 per square foot. Another option is to paint the existing interior walls. It may be a better option for homes with voids. But the cost of soundproof paint is still quite high.

Soundproofing can be expensive, ranging from $23,000 to $46,000 to soundproof an entire home. The cost depends on how many rooms need to be soundproofed, whether you do it yourself and how much noise you want to avoid. many neware the condos soundproof?Tactics included in your building process. Builders can double up drywall in noisy areas and install soundproofing in addition to thermal insulation. Depending on the type of soundproofing you choose, the cost can range from $1 to $3 per square foot.

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The importance of basement insulation

A true Michigan basement is a narrow room dug out of a basement. Because of the location, they are known to have low ceilings and are very humid. The basement was originally designed as an additional storage room; However, over time, the cellars are being restored and remodeled to allow for other options.

These basements were known to have moisture problems due to dampness and water leakage.

There are also well-known structural problems. Homes originally built with basements with exposed earth floors and walls of stone, brick, or concrete blocks. Therefore known to be moldy and unstable.

With basement insulation, you can eliminate frozen pipes, mold growth, polluted air, and water intrusion. It will make your home more comfortable and healthier.

In addition to structural problems and health risks, an undeveloped basement of any kind causes increased energy costs.

New Homes: Insulation options abound

What R-Value Insulation For Interior Walls - InsulationProTalk.com (2)

The new building opens up insulation options for yousignificant. Modern homes have one major advantage over those built 20 years or more ago. They typically have outer shells that allow fewer air changes per hour, making the wall system less reliant on insulation. New seam-sealed wall cladding, sealed house wrap, sprayed house wrap and other innovations effectively reduce overall leakage and spot application of sealant and penetration of foam seal.

This levels the playing field for different types of insulation and adds weight to each product's R-value rating. In other words, you can get good performance from any type of insulation.

The difference now is the cost, the available cavity: are you building with a 2×4″ frame or a 2×6″ frame? Are you ready to consider building parallel walls to achieve super high R-values ​​for your walls? Of course, I am assuming here that you have chosen traditional beam frames, not statically isolated panels or insulated concrete formwork, which are good alternatives.

Ultimately, building codes require a certain level of insulation for any new home. But you might want to go further: try to achieve a net-zero return, where you can say your home is carbon neutral.

Thermography can detect where the walls or ceiling are losing energy. In this Arizona home, the red areas represent locations where high outside temperatures are transmitted inside.

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What insulation is best for exterior walls?

A good R-value for exterior walls is R-23. To achieve this, you can use one of these exterior wall insulation materials:

  • Cellulosic insulation.
  • battery insulation.
  • Open or closed cell spray foam. Closed-cell spray foam is better for exterior walls because it's waterproof, has a higher R-value per inch of thickness than the open-cell type, but is also more expensive.

Extensions and new buildings

Renovation often involves new construction, such as B. adding a room or wing. New builds offer the opportunity to install a continuous air and vapor barrier and a high level of insulation in an efficient and cost-effective manner.

Figure 7-12 shows a typical cross section of a new build from roof to foundation. Watch how both the insulation and the air barrier work continuously without interruptions or thermal bridges.

Renovations also allow for current or future renewable energy certificates and other energy efficient features in your home, such as solar hot water, passive solar heating, underfloor heating, and photovoltaic power generation.


A high level of insulation, a continuous air and vapor barrier and ventilation are the hallmarks of an energy efficient penthouse. Roof trusses are available that allow a high level of insulation over the top panel of exterior walls. These include raised heel trusses for flat roofs, scissor trusses for cathedral ceilings and parallel chord trusses for flat roofs.


The portion of the image to the right shows a 2 x 6 wall with insulated siding. Other wall systems include internal cross bracing, double wall systems and the use of trusses. These systems allow the partially continuous barrier of air and vapor in the wall. Consider recessed headers that allow for a continuous air and vapor barrier and additional insulation.



mechanical systems

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DIY or professional installation

Once you've decided where in your basement you want to insulate and what type of insulation you want to use, the next step is deciding how to install it. Like the insulation itself, installation involves a variety of costs.

When deciding whether to do the job yourself or hire a professional, one of the first things to consider is the complexity of the job. Some parts of your basement are just easier to insulate than others.

Here is an example:

You have concrete block walls and want to add rigid structuresfoam board insulation. This scenario is simple enough for even a novice DIYer. It doesn't require any special equipment or skills. Heck, you don't even need protective gear. In this scenario, it may be worth sacrificing a weekend to tape foam board to the wall to save some money.

But what if you're thinking of installing spray foam on your walls or ceiling? Spray foam is more difficult to apply correctly if you are inexperienced. Roofs can contain pipes and ducts, which complicates the installation process, not to mention the equipment and safety gear required. This is where you can decide that the extra expense of hiring a professional is worth it.

You should definitely consult a professional if your basement is suffering from any type of moisture problem. Improperly installed insulation can lead to mold growth, which can cause serious health problems.

Isolate the ribbon beam

Complete ProPink® Blown Wall System: Sale value for builders

Cut short lengths on the joists running perpendicular to the upper floorunlined batt insulationand press them between the joists and against the side joists. On walls parallel to the studs, press the insulation kraft paper side toward the floor above and hold in place with wire insulation staples pressed between the studs. Clad insulation can only be used if it is covered with drywall.

Helpful tip

In very cold climates, tape backings with fleece insulation can cause condensation on the tape backing. Alternatively, extruded blocks can be carefully cutPolystyrolschaumseal against the beam and withsealaround the perimeter. This prevents moist room air from getting behind the insulation. Cover the insulation with drywall for fire safety.

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