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What is a Hot Roof?

attic insulation | FAQ

What is a Hot Roof? Blog Feature

By: Malcolm Bean on September 21st, 2022

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While doing your research on insulating your attic, you may have come across a term you’ve never heard of before – hot roof.

So what exactly is a hot roof? Well, it’s probably not what you think.

RetroFoam of Michigan has more than 20 years of experience, and when it comes to terminology in the field, we’ve got you covered. We also know a whole lot about spray foam misconceptions.

In our ongoing efforts to educate homeowners, we will explain what a hot roof is and what that means for your home.

What is a Hot Roof?

The term hot roof comes from the earliest days of insulating attics.

Some people believed insulation was actually a heat source, even though, in actuality, it is a barrier between two areas of different temperatures.

For example, your warm attic space compared to your snowy roof.

Even though the term hot roof is a bit of a misnomer, you’re still wondering what exactly it is.

Another term that describes a hot roof much better is an unvented attic.

Let's talk a little bit more about unvented attic and vented attic systems.

Unvented Attic System

If the roof deck of your home has been insulated, it is actually now a part of your home’s conditioned space.

This is a great benefit as it helps prevent ice dams and helps save you money on monthly energy bills. These savings come from the air seal created by the spray foam on the roof deck. The air you pay to treat won't leak out through the roof.

As for the hot roof theory, the unvented attic system could make the temperature of your roof go up a little but fear not. This possible temperature increase of a couple of degrees won’t cause damage to your roof or shingles at all. In fact, the insulation will make sure the only thing your shingles have to worry about is the sun, which they are designed to handle.

Vented Attic System

A vented attic system is usually used with traditional insulation like fiberglass or cellulose.

The unvented system is more energy efficient and the usual practice when installing spray foam insulation. With that being said, there are instances when the vented system is the better approach.

Essentially, the vented attic system seals the attic off from the rest of the house. This happens because the attic flat is sprayed with foam, creating an air barrier between the attic space and the living area.

Want More Info on the Benefits of an Unvented Attic?

It’s too bad that an unvented attic is called a hot roof because it is much more about having a conditioned attic that doesn’t cost you money on monthly energy bills.

Don’t let that ominous hot roof label fool you, it’s one of the best options for your roof as it will save you from costly repairs from damaged caused by ice dams.

If you’d like to learn more about using spray foam to create an unvented attic system for your home, give us a call at 866-900-3626 or fill out the form on our website to schedule a free in-home estimate.

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