Do You Need To Insulate Interior Walls?

Building codes often require a minimum amount of insulation for the house’s exterior walls and ceiling. On the other hand, there is not a minimum requirement for interior walls.

Therefore, insulating interior walls is not as common as exterior walls. Interior insulation offers sound-dampening benefits, as well as energy savings.

So, the question is: do you need to insulate interior walls? The following article provides an answer…

Interior Wall Insulation: The Basics

Depending on the material you use and how it is applied, you can install interior insulation on your own, or hire a professional. You can add insulation to existing walls, even though the best time is during new construction.

In any case, consulting with an expert is always the better option. A contractor will help you chose the best insulating material, as experts are familiar with R-value and how to provide the necessary thermal protection.

Interior wall insulation is a must when there are “party walls”. These are walls that separate individual living spaces found in apartments and duplexes. You definitely need to reduce sound and thermal transfer

Advantages of Insulating Interior Walls

The best way to answer the question ‘do you need to insulate interior walls’ is by listing the advantages of the process.

First and foremost, interior insulation offers sound dampening benefits. Adding insulation will reduce the noise and sound transfer from one room to another. Sound travels through wood framing as well, so insulation will not provide a complete soundproof barrier. However, the noise will be vastly reduced.

Interior insulation also provides energy savings. If you have rooms that are not in use all-year-around, interior insulation will save a lot on the utility bills. Some rooms that are suitable for interior insulation include unused guest rooms, storage rooms, and three-season rooms.

Interior insulation will reduce the heat transfer that happens due to unused rooms. So, if you have unused rooms, the answer to the question do you need to insulate interior walls is yes. In areas with extreme temperature fluctuations, simply closing off rooms that are not used will not help.

Interior wall insulation is a must when there are “party walls”. These are walls that separate individual living spaces found in apartments and duplexes. You definitely need to reduce sound and thermal transfer.

Imagine if nobody is living in the apartment that is linked to you by party walls? Because that apartment gets no heating, it will “steal” all the heat from your apartment.

Why Do Some People Avoid Interior Insulation?

Interior insulation is not always welcomed. Some people choice to avoid insulating interior walls. They insulate only the exterior walls and ceiling. And that is their choice. Simply put, there will always be people that believe interior insulation is a luxury that you do not need to pay for.

Internal wall insulation usually costs half the price of external wall insulation. Now, external is always better, but sometimes, people cannot afford that much money.

Internal wall insulation comes with its own set of problems. Your home is already a thermal envelope thanks to external insulation, so it is sometimes unnecessary to insulate the interior as well.

We have to note that internal wall insulation can sometimes be disruptive and require removal and refixing of items like radiators, kitchen units, and switches.

We have to note that internal wall insulation can sometimes be disruptive and require removal and refixing of items like radiators, kitchen units, and switches

Insulation Materials

Should you desire to add interior insulation to your home, you need to know your options in detail. There are several, main materials suitable for interior insulation. Let’s see how these key contenders compare:

Fiberglass Batts

The R-value of fiberglass batts is between 3 and 4 per inch. For a 2-by-4 framed wall, you will reach an R-value of 13. This is a material that can be used for a D.I.Y project, and is best used for walls, floors, and ceilings.

Pros:

• Widely available
• Designed to fit between joists, rafters, and studs
• Paper and foil faced versions are extremely easy to install

Cons:

• Can be itchy to install
• Fibreglass is not as effective at filling cavities as other materials

When choosing an insulation material, you should always aim to put thermal efficiency at the very top of the agenda!

Rockwool Batts and Blankets

Another material that you can install as a do it yourself project. The R-value of Rockwool batts is between 4 and 5 per inch, resulting in R-15 for a 2-by-4 framed wall.

Pros:

• Fire resistant
• Springs into shape against studs, making insulation staple-free
• Doesn’t itch

Cons:

• Not widely available
• Retains moisture, which can result in mould growth

The R-value of 3.2 to 3.8 per inch is also solid. In terms of environmental credentials, cellulose is made of 85% post-consumer recycled paper

Loose-Fill Cellulose

A versatile product, loose-fill cellulose can be used for ceilings, existing walls, new wall cavities, unfinished attic floors, and any other place that is hard to reach.

Pros:

• Effective in all temperatures
• Performs better as the air gets colder

Cons:

• Too heavy for use as attic installation
• It can settle over time, reducing the effectiveness by 20%

Spray foam expands in volume by up to 100 times its original size, forming an all-encompassing barrier to seal even the most hard-to-reach places with ease!

Open Celled Spray Foam: The Basics

Open cell spray foam is one of the best material for insulating walls, as it provides air and noise barrier. Sprayed as liquid, foam expands and seals all gaps, cracks, and air leaks.

Open cell spray foam has an R-value of 3.5 to 3.6 per inch, and is best used for walls, floors, and ceilings. The R-value increases to 13 for a 2 by 4 framed wall.

Pros:

• Stops movement of air
• Provides an air-tight seal
• Unrivalled thermal efficiency

Cons:

• You need a moisture barrier in some situations
• Requires professional installation

Spray foam is totally inert, odourless, and produces no harmful emissions after installation-making it an all-round healthier alternative than other types of insulation on the market!

Why Open-Celled Spray Foam Does It Better

Developed some 30 years ago in Canada, spray foam was designed as a safer alternative to urea formaldehyde insulation. Here are some features of spray foam that prove why it’s best option for insulation, whatever the task may be:

• Low thermal conductivity, resulting in great thermal performance, for both new and existing structures
• Spray foam is totally inert, odourless, and produces no harmful emissions after installation
• Spray foam expands in volume by up to 100 times its original size, sealing even the most hard-to-reach places with ease
• Provides superior soundproofing properties
• Unlike traditional insulation materials, spray foam doesn’t sag over time

Desperately seeking further insulation advice? Get in touch with our friendly team today by calling 0800 1700 636, or by simply clicking the button below!