Your Garage Doesn't Have to Be Cold—How to Insulate It Like a Pro

garage door in winter with snow

Jason Finn / Getty Images

Project Overview
  • Working Time: 2 - 4 hrs
  • Total Time: 3 - 5 hrs
  • Skill Level: Beginner
  • Estimated Cost: $50 to $150
  • Yield: Insulated garage door

The garage is a great place to store a wide variety of tools, appliances, and vehicles, and the extra space can also be used for a range of different purposes from DIY projects to a home gym. However, most garages are not built with heating, cooling, or insulation, making them uncomfortable spaces in the dead of winter or when summer heat is at its worst.

Insulating the ceiling and walls of the garage is a good start, but if you don't insulate the garage door you could still be losing a lot of heat, leading to higher energy costs. If the garage door is insulated, the space will heat up quicker, plus the insulation can help dampen outside noises.

Use this guide to learn how to insulate a garage door properly and for help deciding on the right type of insulation for your garage door.

What You'll Need

Equipment / Tools

  • Tape measure
  • Pencil
  • Utility knife

Materials

  • Double-sided tape
  • Retention clips
  • Fiberglass insulation

Instructions

How to Insulate a Garage Door

  1. Mark the Retention Clip Location

    Start the project by measuring and marking where the retention clips that hold the insulation in place will be installed. Make two marks on each panel of the garage door. The marks should be vertically centered and about 12 inches away from the panel's edge.

  2. Install the Retention Clips

    Apply adhesive double-sided tape to each panel where you made the mark for the retention clips. Once the tape is in place, press a retention clip firmly against the tape. Repeat this process until every panel has two retention clips installed.

  3. Measure and Cut Insulation

    Use a tape measure to take measurements of each garage door panel, then use these measurements to cut the insulation into appropriate sized pieces with a utility knife.

    Make sure to measure from the inside of the panel and wear appropriate safety gear when handling the insulation, including safety glasses, long pants, gloves, a long-sleeve shirt, closed-toe shoes, and a face mask.

  4. Insert Insulation and Fasten Retention Clips

    Position fiberglass batts against the garage door, then use a utility knife to make a small cut in the fiberglass where it lines up with the retention clips. Slide the retention clip through the small opening, then fasten the retention cap into the clip until you hear it click into place.

    Repeat this process with each panel of the garage door to complete the project.

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How to Choose the Right Insulation

Before you begin, it's important to take the time to select the right insulation for your door. The most common options include rigid foam insulation, cellulose insulation, spray foam insulation, and fiberglass insulation; the most affordable and easiest to work with for DIYers is fiberglass insulation.

You will also need to choose between a garage door insulation kit that comes with pre-cut insulation materials or purchasing the materials yourself to customize them to fit the specific garage door.

The last consideration is the R-value of the insulation. R-value refers to the ability of the insulation to slow the transfer of heat through the material. The higher the R-value, the better the insulation is at reducing heat transfer. However, this doesn't mean you need the highest R-value available. If you live in a cold region, choose insulation with an R-value on the higher end, but if you live in the a warmer climate you can choose a lower R-value.

FAQ
  • Does insulating a garage door make a difference?

    Insulating a garage door can make a big difference in the temperature inside the garage. It can also help to reduce unnecessary spending on heating and cooling by slowing the leakage of heat through the garage door. Not only does the insulation help maintain the temperature inside the garage, it also blocks out noise to keep the garage quieter.

  • How much does it cost to insulate a 24x24 garage door?

    The cost to insulate the garage door in a two-car 24x24 garage ranges from $90 to $530 depending on the type of insulation and whether the job is completed by a DIYer or by a hired professional.1

  • Should you insulate an unheated garage door?

    Even if the garage is unheated, it's still a good idea to insulate the door because it can improve the comfort level inside the garage and may potentially save you money on energy costs by reducing the transfer of heat through the door. Insulating the garage door can also dampen noise coming from outside and the stable temperatures can help protect any items that are stored in the garage.

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  1. 2025 cost to insulate a garage | prices by size, material & location. (n.d.). HomeGuide. https://homeguide.com/costs/garage-insulation-cost