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Interior Walls Insulation


By Grace Henry on April 1st, 2022

When you think about insulating your home, the first things that might come to your mind are your attic, your basement, or your exterior walls. But did you know that insulating the interior walls of your home can also improve your home’s acoustics . Read on to learn more about the acoustical advantages of insulating the interior walls of your home.

Improve acoustics and insulate your interior walls 

Sound traveling between rooms can be annoying. Adding insulation behind drywall can help create a peaceful indoor environment by reducing noise levels. The insulation works to improve acoustics by absorbing the sound within wall cavities, minimizing the sound transmission from places such as your laundry, bathroom, or kitchen.  

A home’s acoustical performance can impact you and your families well being. According to the Insulation Institute, noise has been identified as causing physical and psychological stress on occupants. Acoustics can be measured by Sound Transmission Class and the rating determines what others can hear on the other side of the wall. Higher STC ratings indicate better performing sound insulation. 

STC RatingWhat Can Be Heard
25Normal speech can be understood
30Loud speech can be understood
35Loud speech audible but not intelligible
45Must strain to hear
48Barely audible


However, the STC rating will differ from room to room. Bedrooms should have a rating of 52, while bathrooms, kitchens and living rooms have a rating of 55.9. Adding insulation between the walls of your rooms might be a great investment for your own peace and quiet. 

Application of Membrain insulation

Important steps to determine your insulation needs
Before adding insulation to your interior walls, the first step is to check the condition of the walls to make sure they are prepared for insulation.

The second step is to determine the type and amount of insulation you’ll need. The thickness, the dimensions, and the number of interior walls that need to be insulated are important factors to consider before adding insulation between the walls of your home.

CertainTeed products to insulate your interior walls
If you are thinking about insulating your home’s interior walls, you need to know your options. CertainTeed has some great products that are available for your home and are well-suited to your specific needs. Here are two CertainTeed products you might want to consider for your interior walls:  

  1. InsulPure™ Fiberglass Insulation: Installing InsulPure fiberglass insulation is a cost-effective method to conserve energy and reduce noise levels between the rooms of your home. InsulPure batts can be adapted to different wall sizes and shapes, helping you get the most out of your insulation. CertainTeed InsulPure serves different purposes: you can install the batts where high thermal performance is desired to increase your home’s comfort, and you can also install InsulPure between your interior walls to achieve sound control.
  2. OPTIMA®  Blown-in insulation: The CertainTeed Optima blown-in insulation system is a versatile option if you are looking to improve your home’s energy efficiency and reduce your energy consumption. Optima fiberglass insulation is intended to be used as a thermal and acoustical insulation in closed cavities. It provides exceptional thermal value and acts as a cover to block noise from traveling through your walls. Plus, installing Optima in your wall cavity will reduce the amount of moisture trapped inside!