How to Insulate Walls Without Removing the Drywall? ANSWERED

After a long winter work day, you get home looking to find a cozy spot to warm up. Still, you end up feeling cold wherever you decide to relax.

If that’s the case, it may be time to update your insulation. However, you don’t want to go through the trouble of tearing down your walls. So, you may wonder how to insulate walls without removing the drywall.

Let’s take a look at how you can add insulation without subtracting walls.

What Is Insulation?

While it’s a huge part of our daily lives, many people aren’t familiar with what insulation is.

Usually, this involves placing an insulating material in the stud cavities of a wall. The material can then trap air in the openings. This allows you to separate the outside environment from that of your house.

That means that you can keep your house cool during the summer and warm in the winter. Not only will this help with temperature control, but it can also reduce your heating bill.

The most common types of insulation are fiberglass and cellulose. These materials are lightweight and do an excellent job of holding air.

However, you would need to expose the stud cavities to install either. This can be difficult to do unless you’re planning major renovations.

So, to get around this issue, you can use injection foam insulation.

What Is Injection Foam Insulation?

Injection foam is a resin material consisting of two parts. Separately, each one of the parts is a liquid. When you mix them together, a chemical reaction causes the foam to harden slowly.

Before the reaction ends, you have plenty of time to inject the foam into the stud cavities. It will flow and fill up any nooks and crannies it comes across.

Another added bonus of using injection foam is it doesn’t lose its shape. Also, unlike other traditional insulation methods, it doesn’t settle or compress over time.

This method is similar to spray foam insulation. Yet, injection foam cures much slower and

expands less. For these reasons, it’s the better option for enclosed spaces.

How to Insulate Walls Without Removing the Drywall

The process of insulating your home without removing drywalls is a little complex. However, with the right tools and guidance, you should be able to do it without any issues.

Collecting Materials and Tools

Before you start insulating, collecting all the materials and tools you’ll need is best. These materials are:

-Insulation foam

-Insulation injector


Stud finder



-Safety goggles


-Gloves (optional)

-Drywall tape


-Prepping the Walls

Once your equipment is ready, you can start clearing the walls. Since you’ll be using power tools in the area, removing fragile items is a good idea.

You also want to remove any furniture away from the wall. Then you can lay out the tarp directly under it to catch drilling debris.

After that, it’s time to pull out the stud finder. Using the device, locate and mark the studs cavities.

Drilling the Holes

With the studs marked off, this process should be straightforward. You need to make two drill holes per cavity—one at the top and the other towards the middle.

These holes should be about two and a half inches in diameter. This is more than enough space to allow you to slip the injector in easily.

Maneuvering the Injector Hose

The best way to add the insulating foam to a cavity is from the bottom up. So, the next step is feeding the injector hose into the bottom drill hole.

You want to slowly push the tube down the cavity until you reach the bottom.

Injecting the Foam

With your hose at the bottom of the stud cavity, you want to press on the injector trigger gently. As the foam exits the device, gradually pull out the hose.

Take your time with this part of the process. You want to make sure that the foam is entering every crevice.

Once you’ve filled the bottom section of the cavity, you can move on to the upper hole. Then, repeat the same procedure.

During this process, it’s perfectly normal for dust and debris to come off the hole. This shouldn’t affect your insulation, but it can damage your lungs.

For this reason, ensure you’re wearing safety goggles and a mask. It’s also not a bad idea to wear gloves to keep your hands safe.

Patching the Holes

After filling the stud cavities with foam, it’s time to patch up the holes.

The easiest way to do this is to use drywall cutouts. You can carve discs from scrap drywall that you have lying around.

You place the cutout in the hole and use drywall tape to secure it. Then, you cover the area in spackle and let it sit.

Once it’s dry, you can then sand the surface to make it smooth. This will make painting the wall much easier.

We have discussed how to insulate a wall from the inside here as well.

If you don’t have access to scrap drywall, you can just use spackle. However, you’ll need to use a lot more of it, and the patch won’t be as sturdy.

The entire process is possible on your own. However, it’s not exactly straightforward. You may be able to follow the steps under perfect conditions, but there are a few steps that can go wrong.

Filling the stud cavities all the way is a little tricky, and you may need someone to help you.

Instead of worrying about this, you can hire a professional. They can perform the process much faster and more effectively.

We have discussed how to hang shelves on drywalls here.

Wrapping Up

The answer is simple if you’re wondering how to insulate walls without removing the drywall. The easiest way to do it is using injection foam insulation.

It’s a material that starts out as a liquid and solidifies over time. Because of this, you can inject the insulation foam into the cavities by drilling holes into them.

Passive houses use a lot of insulation and try to reduce energy usage. While this might not be achievable for any house, adding insulation is a great first step.

Once you successfully fill the cavities, you can patch the wall with some spackle.

We have discussed how to clean a drywall here.