Home Insulation Installation

What You Need to Know About Adding to Your Existing Insulation

A poorly insulated attic means an energy-inefficient home. In the winter months, warm air escapes from your living quarters into the attic and out of the house. In the summer months, warm air builds up in the attic and invades down below.

Hot air is always seeking cold air. Insulation is the best way to keep it where you want it.

If you haven’t been up in your attic lately (or ever), you might be in for a surprise. Insulation doesn’t last forever, nor is it impervious to weather, moisture, or mold.

If your home isn’t maintaining the steady and stable temperatures you’d prefer – or if your energy bill is higher than it ought to be — there’s a good chance your attic insulation isn’t up to snuff.

This leads us to one of the most frequently asked questions among Colorado homeowners: can I add new insulation over old insulation? There’s a short answer to that question and a long one.

The Short Answer: Can I Add New Insulation Over Old Insulation?

Yes! You can absolutely new insulation over old insulation… as long as it isn’t wet.

Energy Star advises as follows: “If it… appears that the insulation [is wet or] has previously been wet, you should look for the cause and repair the problem to prevent a reoccurrence. Remove any wet insulation. Wet insulation can lead to mold, mildew, or even the rotting of your ceiling or roof rafters.”

In fact, you can add new insulation over the existing installation in other areas of your home, not just the attic. And you don’t even have to choose the same material used in your existing insulation. Rather, you should decide on the material that best meets your current needs, considering all of the following:

  • Energy efficiency
  • R-values (effectiveness of the insulation)
  • Your budget
  • Any health concerns you might have
  • Durability of the insulation material
  • Eco-friendliness of the material

Things to Keep in Mind When Installing New Insulation Over Existing Insulation

You have a few choices about the type of insulation you might install atop your old insulation:

  • Batt insulation
  • Rolled insulation
  • Blown / loose-fill insulation (e.g. cellulose, fiberglass)

Each choice comes with its own set of pros, cons, and advisories. For example, if you choose rolled or batt insulation, you need to make sure it isn’t “faced” (meaning it shouldn’t have a foil, paper, or vinyl vapor barrier). Putting faced insulation over old insulation in an attic is a big no-no because it will trap moisture and lead to long-term problems.

Similarly, you must take care not to tack down or flatten any rolled insulation, as doing so will compromise its effectiveness.

The method of installation matters too. New insulation should be positioned so that it is perpendicular to your existing joists.

These are just a few of the most important considerations. There’s a lot to know about adding new insulation over old insulation, and mistakes are easy to make.

That’s why we recommend consulting with a professional, who can install your new insulation for you and make sure it’s done the right way on the first try. It’s easier to avoid a mistake than to go back and correct it.

Just Because You Can Add New Insulation Over Old Insulation Doesn’t Mean You Should

Adding new insulation isn’t always the answer. Consider the following:

  • Insulation that is very old, damaged, and not performing well should be completely removed and then replaced with all-new insulation.
  • The insulation itself might not be the problem. You could have air leaks around your windows, ventilation issues in the attic, or other hidden issues that keep your home from operating at optimal energy efficiency.
  • Before you add any new materials, make sure your old insulation doesn’t contain asbestos.

Can I Add New Insulation Over Old Insulation All By Myself?

There is a right way to add new insulation over old insulation… and plenty of wrong ways too. Despite what you might read online, it’s not necessarily an easy “DIY” job.

It is easier to avoid a mistake than to go back and fix it later. Getting things right the first time is more cost-effective too.

That’s why Energy Star advises hiring a local home energy company to evaluate your attic, make suggestions on how to proceed, and offer installation services accordingly.

Schedule a Home Energy Audit in Denver or Fort Collins, CO

REenergizeCO is a Denver-based home energy company that helps homeowners and businesses diagnose their energy efficiency problems and then correct them cost-effectively.

In line with Energy Star’s recommendation, we recommend that homeowners schedule a home energy audit with our team of local home energy experts. We’ll come out to evaluate your attic’s insulation (as well as any air leaks or other energy zappers in your home) and then make suggestions about how to proceed.

If adding new insulation over old insulation is the option that makes the most sense for you, our professional installation team can recommend the right type of insulation and then proceed with installation when it’s convenient for you.

To get started, simply contact our office and schedule a home energy audit in Denver or Fort Collins, CO today.