The walls of your home aren’t protecting you from the hot and cold as much as you’d like but insulating them with foam seems complicated to you because you have a brick exterior.

But it’s not the exterior itself that is throwing you for a loop. It’s whether you should have foam injected into the wythe cavity, which is closer to the exterior, or the stud cavity just beyond.

RetroFoam of Michigan has insulated tens of thousands of homes across the lower peninsula since 2002. In that time we have used injection foam in exterior walls with different siding types, so we know exactly what is best in each instance.

With our experience, we know the best way for insulating existing exterior brick walls and we’ll share that knowledge with you now.

Insulating Existing Exterior Brick Walls

Before we get started, let’s make sure you understand what the wythe cavity is.

In this instance, the wythe cavity is a small air space between the brick exterior and the stud cavity. On one side there is brick and on the other, there is the sheathing that separates it from the stud cavity.

On the outside looking in on this matter, you’re likely thinking insulating that wythe cavity would make the most sense, but that’s not the case.

Our preferred method when deciding whether to insulate the wythe cavity or the stud cavity is the stud cavity and here’s why.

We and any other good contractor want to preserve your brick exterior. As the injection foam enters the wythe cavity, there is the possibility that the pressure could push out the bricks. Because of this possibility, installers take their time and the process takes much longer, but even with this precaution, the bricks could push out.

Because of this, the preferred method is to drill into the brick, through the wythe cavity, and right into the stud cavity to inject the foam.

That being said, there are times when the wythe cavity is the best option.

For example, if there is cellulose in the stud cavity, then the wythe would be insulated instead.

Another scenario is if the walls have paneling. The injection foam can cause the paneling to push out, which can be difficult to fix depending on how the paneling is attached.

Foam Insulation for Your Home

You know what your home needs, and that’s insulation that will stop the outside air from getting inside.

Injection foam in your existing exterior walls can get that done.

In the case of the wythe cavity versus the stud cavity, it’s always best to have a professional take a look because every project is different. The big thing is to have a conversation with your foam insulation contractor to make sure the integrity of your brick siding will be maintained.

If you’d like to learn more about the benefits of foam insulation in other areas of your home, check out our Learning Center.