Choosing the best insulation material for your do-it-yourself garage insulation project.

As you know, one of the least energy efficient areas of our homes is the garage, specifically the garage door. Most garage doors are made of aluminum, steel or wood and are usually installed uninsulated. The typical double garage door is 7 ft. x 16 ft. That’s over 100 sq. ft. of uninsulated space. Whether you have a single or double car garage, your uninsulated garage door is allowing heat in during the summer and letting heat escape during the winter.

I’ll bet you’ve probably felt how hot your garage door gets in the summer and how cold it is in the winter. Well this is the sign that it’s time to correct the problem and start reducing your energy bills.

And if your water heater is in the garage, it’s efficiency is affected too. The colder it is in the garage the longer the water heater has to stay on to keep the water temperature constant — which means a higher energy bill.

Since there are several different insulating materials to choose from, it’s not surprising that this is one of the most often asked questions I receive;

“Which insulation material should I use to insulate my garage and water heater?”

Fortunately I have a simple and inexpensive answer as well as a couple of tips to help make your do-it-yourself insulation project a breeze.

So here we go.

Types of Insulation Materials

First let me explain the different kinds of insulation materials available to you.

Spray Foam Insulation

Two part spray foam is very effective but you’ll have to buy a kit (about $350 for a double garage door) or hire a professional to perform the work. That makes this material the most expensive choice.

Rigid Foam Insulation

Although Rigid foam is less expensive than spray foam, it’s also a bit less effective due to a lower the R-value — which leads me to what I believe is the best material choice for this do it yourself home insulation project.

Prodex Insulation

ProdexProdex insulation, commonly known as a radiant barrier, is the DIYers best choice for these types of insulation projects because it’s inexpensive, easy to install, and very effective. It also has a built-in bonus I’ll tell you about later.

Prodex Total insulation is only 1/4 inch thick and made of a closed cell foam core covered on both sides with tear resistant foil. This amazing radiant barrier reflects 97% of the heat. It also offers an excellent R-value and is about half the cost of rigid insulation

For about $120 you can easily and simply insulate your garage door and water heater, and immediately begin saving energy.

DIY Tip Be sure to order Prodex Total as it has the more efficient closed cell foam core.

Tools and Materials

Prodex Total is easy to install with these simple tools. Click on image to view more details on Amazon.

Garage Door Insulation

Cut the insulation to size and apply it to each garage door section with silicone adhesive. Use foil tape to repair any tears or to cover seams.

(Before) Garage Door Insulation

DIY Tip: Cut the insulation on a piece of plywood to keep from dulling the blade of your utility knife.

(After) Garage Door Insulation

DIY Tip: Be sure to position the insulation quickly as the silicone will set fairly fast.

You may have noticed the extra bonus I was talking about from the photos — the highly reflective quality of the insulation will instantly brighten your garage. Nice.

Insulating the Water Heater

Since you’re insulating your garage door, go ahead and insulate your water heater too. Remember, even if your water heater is in the house, you can save money by insulating the tank. Use the same radiant barrier insulation to insulate your water heater.

Insulated Water Heater

DIY Tip: Make cut-outs for the pilot and thermostat access. Use a bit of duct tape to secure those pieces so you can easily access them later.

PLEASE be sure to read, understand and follow all safety precautions and procedures when working with, near, or around any gas or electric water heater, or for that matter any appliance. You can also refer to my Insulation Do’s and Don’ts article for more tips.

So, when you’re ready to undertake your do-it-yourself garage insulation project and you’re faced with selecting from multiple insulation materials, I highly recommend Prodex Insulation. It’s a great radiant barrier and can be easily purchased from They also have a garage door insulation kit here.

If you have questions about your DIY projects, just ask your personal DIY consultant. I’m here to help you succeed with speed.