Internal Wall Insulation- Benefits and Types

Internal Wall Insulation- Benefits and Types
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Did you know? Around 35%to 40% of heat loss in a house occurs through windows, walls, and doors in the winter. That mainly happens in older houses, which have solid brick walls, where the result is the climate effect and more spending on electricity to keep the room temperature stable during the summer and winter.

However, there’s a growing concern of climate change and rising energy bills. House owners are looking for an alternative way to make their homes energy efficient. This is where the Internal Wall Insulation comes as a great solution.

It’s an additional layer of wall that is installed on the interior of the outside wall to prevent heat loss during winter and cool air during summer, reduce noise, save money on energy bills and be environmentally friendly.

These days internal wall insulation is getting popular because of its numerous advantages. But, there are so many homeowners who are unfamiliar with internal wall thermal insulation. Don’t worry!

So, if you’re planning for internal wall insulation in your home as a cost effective and energy efficient solution, then keep reading.

In this guide, we will deep dive into detail, its types, how it works, benefits, and how to install in your home. Let’s find out!

What is Internal Wall Insulation?

Internal wall insulation is a process of adding insulation materials to the inner side of a building’s external walls. These insulation materials act as a thermal barrier on the inner walls which keep the warmth within the building during winter and cool air during the summer.

This helps to keep the building’s inside temperature appropriate and control the temperature flow. It overall leads to reducing energy bills and is environmentally friendly.

In some cases, it is also called Drilling, which is bonded or screwed to the walls. Internal wall thermal insulation is a cost effective option for homeowners who have solid brick walls, have high energy consumption, or are planning for renovation.

Benefits of Internal Wall Insulation

Here are some key benefits of internal wall insulation:
Internal Wall Insulation Benefits

1. Improved Energy Efficiency

One of the biggest reasons why every homeowner is planning to install internal wall insulation is energy efficiency. If your home is not insulated or has solid brick walls, then the heat or cool air does not stay in your home and transfers through the windows, walls, and doors. And it increases the spend on electricity. However, internal wall insulation keeps the heat during the winter and cooled air during the summer, which leads to energy efficiency and reduces energy consumption.

2. Moisture Control

If your home has moisture infiltration, then it can damage your property, cause poor indoor air quality, and various health risks. That’s why having insulation in the interior walls is a better option. Insulating interior walls have moisture resistant material that acts as a protective layer. It keeps the temperature balanced in summer as well as winter, improves air quality, and prevents mold growth.

3. Cost Savings

After internal wall insulation, it lowers the energy bills by maintaining the thermal temperature and reduces the damage on property. As a result, it saves cost on energy and property maintenance.

Install Internal Wall Insulation in Your House

4. Comfortable Living

Another amazing benefit of internal wall insulation is reduced noise from outside. It overall leads to a comfortable and peaceful living without any outer disturbance and pure air quality.

5. Enhanced structural durability

By installing internal wall insulation, your home is not only soundproof and maintains thermal temperature. But it also helps to enhance the structural integrity and durability of your home. When there’s a proper temperature flow, pure air quality, and noise reduction, then it minimizes the risk of cracks, warping, and other damages and ensures durability for a long time.

Internal Wall Insulation Types

Here are four main types of internal wall insulation that you should know:

1. Rigid Insulation Boards

One common type of wall insulation is rigid insulation. It is made up of dense sheets of foam material such as polyiso, polystyrene, or polyurethane. It is directly placed on internal or external walls and acts as a barrier against heat transmission. However, it’s quite an expensive type of insulation as compared to other types of insulation and requires careful installation.

2. Insulated Plasterboards

It’s a combination between a layer of insulation and a layer of plasterboard which is used. It is also known as foam backed plasterboard or thermal plasterboard. It is an energy efficient insulation type which can reduce energy cost and improve wall’s durability. It’s available in different thickness and sizes with easy installation.

3. Blown-in Insulation

Blown-in insulation is also known as loose fill insulation. It’s a process that blows loose material into cavities with a special machine and hose. There are different types of material used for blown-in insulation such as cellulose, fiberglass, mineral wool, rock wool, natural wool and styrofoam pellets. This insulation has a high R value and tight air seal. However, this insulation might settle with time.

4. Foam Insulation

It is a low density polymer that provides thermal insulation. It’s lighter, has better insulation, and is of high quality. It comes in various forms, such as Spray on foams, rigid form panels, custom pre molded shapes, cellular foams, flexible foams, and more. It’s used in homes, commercial buildings, and other spaces. It’s a better insulation but has a high upfront cost and installation complexity. Also, foam insulation contains some chemicals like isocyanates, which can affect skin and lung sensitization.

Materials Used for Internal Wall Insulation

Here are some key materials used for internal wall insulation:

1. Mineral Wool

Mineral wool is a type of fibrous material which is made from minerals like stone or silica. Two common examples of mineral wool are rock wool and slag wool. They have thermo acoustic properties, fire resistant insulation and are durable. It can not be burned and has low water absorption. It is mainly used because of fire resistant and sound absorbing properties.

2. Polystyrene

Another common material required for wall insulation i.e, Polystyrene. It is mostly used in buildings for heat prevention and available in different formats such as foam, boards and sheets that are placed inside the walls to maintain the thermal temperature. It’s a colorless and transparent thermoplastic which is used to make foam board, beadboard and concrete block insulation. However, the thermal resistance or R value of Polystyrene foam board depends on its density.

3. Polyurethane Foam

Polyurethane is a popular choice for internal wall insulation. Most homeowners and builders use this wall insulation material because of its high R value per inch of thickness, which provides high energy efficiency. It is available in both closed cell and open cell formulas. Whereas closed cell foam has high density cells and is filled with gas to expand and fill the space around it. On the other hand, open cell foam has a lower R value and is filled with air to give a spongy texture. So, it can be used as a liquid spray or rigid foam board.

4. Natural Materials

Some natural internal wall insulation materials are also used such as hemp, wood fiber boards, cellulose, cork, cotton, sheep’s wool, straw or perhaps fluffy insulation batts with a timber framework. These natural insulation are becoming popular among homeowners who are looking for eco-friendly materials for inner insulation.

How to Install Internal Wall Insulation?

Here’s the step by step process of installing internal wall insulation:

1. Preparation

The very first step for internal wall insulation in your home is preparation. It’s very important to keep your things ready, such as choosing the right insulation material and setting up the installation areas, which include clearing furniture, protecting floors from dust, proper ventilation to avoid dust, and electricity outlets cut off for safety purposes.

2. Measuring and Cutting Insulation

Then you need to accurately focus on the measurements before insulation. You need to measure the height and width of each wall where you plan for insulation and calculate the total area. So based on these measurements, you can define the amount of insulation required and cut to fit each section precisely.

3. Fixing Insulation to Walls

Now, it’s time for the internal wall insulation. Here you need to choose which type of insulation you want to install, whether it’s plugs and screws based on a special adhesive, plasterboards, or blown in. However, each installation required professional help. So, you can consider hiring an internal wall insulation service provider for perfect insulation.

4. Adding a Vapour Barrier

After the installation, adding a Vapor barrier is essential to prevent moisture within the wall cavity. First select a vapor barrier then unroll it across the insulated wall and make sure proper overlap at edges and corners. Then cut and fit the barrier around doors, windows and electrical outlets and then use specialized tape to create a moisture proof barrier.

5. Finishing

Once the insulation and vapor barrier are properly done, then you can start focusing on finishing the inner insulated walls, such as installing plasterboard, drywall, or other cleaning materials to give a final look at your newly insulated walls.

Cost of Internal Wall Insulation

Internal wall insulation is a cost effective option compared to external wall insulation. The average cost for internal wall insulation comes on average between $0.50 to $1.25 per square foot. However, the estimated upfront cost of internal wall insulation depends on various factors.

Initial Costs

The cost of internal wall insulation depends on various factors:

  • Type of Insulation:
  • There are different types of insulation available, from rigid boards to blown-in. You can choose any type of insulation based on your budget and preferences.

  • Size of the Wall:
  • Another factor that affects the cost of insulation is size of the wall. If the size of the wall is large then it requires more insulation material and installation efforts that overall leads to more cost.

  • Additional Materials:
  • If you plan for add ons such as fixing, adhesives, a vapor barrier, and finishing, then it can also affect the cost of insulation.

  • Complexity of Installation
  • Complexity of inner wall insulation installation can also impact the cost because of irregular shapes, many windows/doors, electrical wiring complex and that collectively increase the cost.
  • Professional Installation Cost
  • Hiring a professional insulation service provider is essential because installation requires skills and hands on experience, and it’s better to let the professional do it. So that’s another cost of internal wall insulation.

    These factors mainly impact the initial cost of internal wall insulation. It’s always preferred to get a quote from a professional internal wall insulation service provider for an accurate estimated cost.

    Long-term Savings

    While it seems like a high upfront cost for internal wall insulation, there are long term savings. After having successful internal wall insulation, it acts as a thermal barrier. Which will keep your home warm in winter and cool air in summer. It is overall leads to low energy consumption and long term savings.


    Internal wall insulation for solid walls is becoming a popular option for homeowners. It enhances their energy efficiency, reduces electricity consumption, keeps the home noise free, provides comfort at home, and makes the property long term durable. However, there are many things to consider before installing the internal wall insulation. Such as the type of insulation, the material required, etc. We hope this guide helps you know everything about internal wall insulation, its types, materials, benefits, and how to install it. It is highly recommended that you consult with a professional before installing internal wall insulation to get the solution to your specific needs. Now, it is your turn to find the most reliable wall insulation service provider for your home and let the professionals do the things for you.


    1 How Long Does Internal Wall Insulation Last?

    The average lifespan of internal wall insulation is around 25 years. However, it also depends on the type of material used for insulation. It is better to consult with a professional first to get the best suggestion as per the needs of your home.

    2 Can Internal Wall Insulation Be Installed in Older Homes?

    Old houses should prefer internal wall insulation because of their thick stone walls then inner insulation helps to maintain thermal temperature.

    3 What Are the Maintenance Requirements for Internal Wall Insulation?

    Internal wall insulation is highly durable and it remains in good condition for years. However, it’s preferred to inspect at least once a year. Sometimes problems occurred due to negligence such as condensate blockage, use ladders carefully, prevent leaks etc.

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