Is your attic over-insulated?

We realize that it may be strange to think that part of your house could be “too warm” in the winter, but it’s true!  In fact, while it surprises many homeowners, one of the most common causes of property damage is actually over-insulated attics…

And we can certainly understand where property owners are coming from.  You go up into your attic to get your Christmas decorations down and you think to yourself “wow is it cold up here”, and instinctively decide to insulate your attic better, but that could be a huge mistake.  Here are some things to consider:

Why can over-insulating your attic be an issue?

You may think that the purpose of your attic is just to support the roof, but it does a lot more than that.  Your attic space is actually integral in regulating temperature inside your home, facilitating airflow and ventilation, and even extending the life of your roof.  It does all this with the help of the ridge vent, baffle vents, and soffit vents, which allow air to circulate.

When you over-insulate your attic or restrict airflow, serious issues can occur such as humidity problems, mold growth, or even damage to your roof shingles!

What happens if you over-insulate your attic?

There are a variety of ways that an attic can be over-insulated, and each creates its own issues.  Here are some of the most common mistakes we see:

Insulating the attic “ceiling” – Did you know that the ceiling of your attic shouldn’t be insulated?  In fact, because this can prevent your attic from being able to properly cool in the summer, this can lead to heat damage occurring to your shingles and can dramatically reduce the life of your roof and shingles.  In fact, insulating the roof of your attic actually voids many of the warranties that come with roof shingles!

Blocking the baffle vents – A lot of the airflow into your attic space comes in through your baffle vents, so it’s really no surprise that it’s so common for homeowners to block them up with insulation.  We often have conversations with property owners that realized their attic was cold and felt the air coming in through the baffle vents, and decided to stuff insulation down inside or against the baffle vents to keep that cold air out.  This is a huge mistake however, because without that airflow, humidity can get trapped inside your attic, where it will cause moisture problems and mold growth!

Blocking the soffit vents – Your soffit vents can be seen from outside and allow the airflow to the baffle vents.  Unfortunately, we often see instances where siding was replaced and the soffit vents were blocked, closed off, or even forgotten.  This creates a similar issue to blocking off the baffle vents, where your attic doesn’t get the airflow that it needs, moisture and humidity gets trapped in the attic, and mold eventually develops.  While we do see this less often than blocked baffle vents, this is still a common cause of mold issues and moisture problems in attics.

Blocking the ridge vent – Your ridge vent is a large vent along the top of your roof (the ridge) that allows air to leave your attic space.  Essentially, your ridge vent is the last piece in the ventilation system that permits air exchange inside your attic as air that enters through the soffit and baffle vents creates airflow that then exits through your ridge vent.   The two most common issues we see are ridge vents that have been blocked as a result of insulating the attic “ceiling” which prevents the necessary airflow to the ridge vent, or improper roof replacement or repair that either blocks or fails to properly install the ridge vent.  A blocked ridge vent will prevent hot air from escaping, shortening the lifespan of your roof, and potentially trapping moisture in the attic that can lead to mold growth.

How should your attic be insulated?

It’s important to keep in mind that your roof and attic are designed specifically to encourage airflow and ventilation, so when insulating your attic you want to make sure that you are not impeding the function of your ventilation systems (ridge vent, soffit vents, and baffle vents).

That doesn’t mean that your house can’t be warm and comfortable though, but you’ll want to focus your attention on keeping that heat in your living spaces, not unusable space like attics.

The best way to insulate your home and effectively keep your heat in the spaces you use, is by insulating the floor of your attic and the exterior walls of these living areas.  This creates a barrier of insulation that keeps the rooms you use warm and comfortable and prevents this heat from escaping into areas of your home that you don’t use, such as attics.  This way you will be able to stay warm while your attic does its job.

We hope this helps correct some common misconceptions about attics and attic ventilation.  There’s no need to worry if your attic is cold in the winter, it’s supposed to be.

Is your attic over-insulated?  Does it feel humid in the summer?  Have you ever seen mold growing on the rafters or sheathing?  Contact Your Local Disaster Blaster for an evaluation. We’re always here to help!

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