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Airtight House: Can Spray Foam Make My House Too Tight?

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Airtight House: Can Spray Foam Make My House Too Tight? Blog Feature

By: Malcolm Bean on March 30th, 2022

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You know about the benefits of foam insulation for your home, but you still have questions on whether the material can create an airtight house that is too tight.

Your top concern is can a house be sealed too tightly, which could impact air quality and humidity.

When building a new home, it will need to be insulated. The builder you hired will call in a Heating, Ventilation, and Air Conditioning (HVAC) contractor to perform a Manual J test.

This test will determine the HVAC sizing with foam insulation your new house needs.

That HVAC system will help keep your newly insulated home from being too tight. It will also ensure your home has the proper air exchange rate to have the appropriate air quality and a comfortable humidity level.

So, what happens if your house is too airtight? Let's talk about how to fix that.

What Happens if My Home is Sealed Too Much?

While the right-sized HVAC system for a new build house avoids the issue, what about an existing home? Can a house be too airtight?

If the HVAC system in an existing home isn't the right size to work in conjunction with the foam insulation, then the air quality and humidity will be affected.

So, what do you do?

The solution to a house that is sealed up too tight is straightforward.

The fix is as simple as turning on a bathroom vent or kitchen hood once daily. This will exchange the air in the house, so you have fresh air coming in.

No matter which kind of project you’re working on, it is very rare for spray foam to make your new or existing home too tight.

Maintaining indoor air quality for both new build and existing homes will require mechanical ventilation, according to the U.S. Department of Energy.

Foam Insulation for Your Home

Now that you know that ventilation for airtight homes is the answer to the problem, you might have more questions about foam insulation.

We have the answers, along with a ton of great videos and other resources.

If you’d like to learn more about foam insulation in your home or pole barn, check out the Learning Center on our website.

Related Articles

What Should the Humidity Be in Your House?

What is Air Sealing a Home?

Clearing Up Misconceptions About Spray Foam Insulation

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