What Should I Do If My Attic Insulation is Wrong?

Have you recently discovered that your attic has little or no insulation, and now you’re wondering how serious the problem actually is? Are you concerned that low insulation is behind your high energy bills, uneven room temperatures, or even mold and rot in your attic?

At RoofSmart, we inspect hundreds of Seattle-area homes every year. This inspection includes checking out the attic to see if everything is up to code. Often, we find issues like low insulation, poor ventilation, rotting wood, and mold. Having proper insulation is a vital part of making sure your roof functions properly. 

In this article, we’ll walk you through what causes low roof insulation, how to spot the warning signs, and the real risks it can create, especially in Seattle’s damp climate. 

You’ll also learn what your options are for fixing it, how much it typically costs, and how to avoid wasting money on quick fixes that won’t last.

Why does my roof have low insulation?

Unless you’re crawling up into your attic on a regular basis, you probably have no idea how much insulation is up there. It’s one of those things that you would assume you don’t need to look into. 

It’s easy to not notice that your roof has low insulation. In fact, many Seattle homeowners don’t even realize that their insulation is low. 

If you’re confused why there’s not a lot of insulation in your attic, here are some reasons that can help explain what happened: 

• Your home was built like that: Building codes change a lot, and there are a lot of homes in the Seattle area that were built 40 (or more) years ago. Since then, there have been many drastic changes in regulations around insulation. So, it’s possible that your home was only given a little bit of insulation because it was built before anybody knew better. And because you didn’t know that there was a problem with the insulation, nothing's been changed or looked at since.
• Someone moved your insulation around: It’s also possible that you’ve had work done up there, or something has disturbed the insulation that was there. This can cause bald spots throughout the attic where there is no insulation. This issue is really common with contractors (for example, an electrician or an HVAC technician) who need to work in the attic. They just move the insulation out of the way and then don’t put it back. 

It's easy to assume that somewhere along the way, your roof was brought up to code and is meeting current regulations. Unfortunately, this is often not the case. 

It’s usually pretty obvious that something is wrong once you pop your head in the attic and look around.

What problems does low roof insulation cause?

Attic insulation is crucial for regulating the temperature of your home. Without it, you're going to have a lot of heat loss because your roof won’t be able to effectively trap in heat. That's going to lead to higher energy bills.

If you notice big differences in temperatures between rooms, higher energy bills, or have problems with freezing pipes or phantom leaks when it’s cold, these are all signs that your roof might have low insulation. 

But the even bigger problem is that low insulation is going to lead to condensation in the attic in the winter. You do NOT want any sort of moisture build-up in your attic, because that will almost always lead to rotting wood and mold.

Not to mention, mold is hard to clean off of insulation. Once it spreads there, you’re going to need a much more expensive mold remediation job to get rid of it. 

What can I do about low insulation in my attic?

Some homeowners don’t think this is a big enough problem, so they bury their heads in the sand and ignore it. To be clear, we definitely don’t recommend ignoring it because you’ll only make the problem worse. But a surprising number of people choose to do nothing. 

If you want to get rid of mold and rot and fix your insulation problem, here are your 2 options: 

1.) Clean the attic and add new insulation: One option is to remove everything from the attic (including the old insulation) and sanitize everything by hand before adding new insulation.

It's a lot of extra labor, and we find that it's not as effective as fumigation. Here's an example of what the process looks like: 

2.) Fumigation: Instead of taking everything out of the attic and cleaning it by hand, we can fumigate it for you. Unless the insulation is rotting or in some way physically damaged, not just dirty, fumigation is an effective option for cleaning. 

We will sanitize everything with our fumigation and then add in the new insulation. This is a much less time-consuming and labor-intensive option. 

How much does it cost to add more insulation to my attic?

So, how much does it cost to replace the insulation in your home? In general, replacing insulation is somewhere between $3 and $4 per square foot of attic floor space. Topping it off makes it closer to the $2/sqft range.

On top of that, you’ll probably also need to pay for mold remediation, which is going to be a similar price. 

Keep in mind that everybody's situation is unique, so it’s hard to guess how much it will cost. The amount of mold or rot in the roof and the size of your attic will have an impact on the total job cost. 

What Should You Do About Mold in the Attic Once It’s Already There?

Now that you understand how low insulation can cause serious moisture problems in your attic, especially in Seattle’s damp, cold climate, it’s clear that ignoring it can lead to costly consequences. From skyrocketing energy bills to dangerous mold and wood rot, this isn’t something that gets better with time.

But if you’ve already discovered mold in your attic, the next step is knowing how to handle it safely and effectively.

Read “What Should I Do If I Have Mold In My Attic?” to learn how attic mold is professionally treated, whether you need full remediation or just sanitization, and how to make sure it doesn’t come back after you’ve fixed the insulation problem.