How To Insulate a Garage CHEAPLY! My Simple Trick


You don’t always have access to or the budget to purchase insulation with a high R rating. So what are the options if you still need to find an effective solution to keeping your garage warm cheaply?

Believe it or not, there are a few super effective options that you can do to keep your garage warm without having to open your wallet!

In this article I’ll share some of the techniques I found during my research and why exactly they work so well. You’d be surprised why types of insulation and where to place it gives you your biggest bang for your buck.

Air Gaps

Before we start talking about types of insulation you can use, it’s just as important to know where exactly is the best place to your makeshift insulation. Let me explain, the principal is pretty easy to understand.

You could buy the best insulation in the world but if you leave a bunch of air gaps around areas like garage doors, roofs and windows then heats going to escape outta there quicker than a college kids at the start of spring break.

You’d be amazed just how much heat can be lost in what to my eye looks like a really small air gap. In the case of my garage you couldn’t even get your picky finger through the gap I found, but it was dumping heat into the atmosphere.

One not so obvious air gap culprit is the gap around the top and bottom of your garage door. This is because a perfect seam isn’t always formed when it closes. As a result heat escapes.

The good news is you don’t need to invest in any super high tech solution to close these gaps. For me I found that for gaps in the joints of wood I could use expanding glue foam. That filled the gaps nicely.

For larger gaps or spaces that expanding foam isn’t suitable for you can use an old towel or any kind of dense fabric that will cover the gap effectively. What I did was hot glue the fabric to the edge of the garage door. That way when it was lowered if covered an air gap at the bottom of the door.

Air gaps occur around the edges of a garage door

If you have an older garage door you could also look at adjusting the power of the motor. If it’s turned down then it might not be applying the right amount of pressure when the door is fully closed. This results in a poor seal between the door and the floor of the garage. Try turning the power up slightly on the garage door openers motor.

Note that on modern garage doors the power setting of the motor is controlled electronically and you’ll need to bring in a technician to adjust it.

Be Careful What Insulation You Use

Now we know how to deal with air gaps, let’s talk about insulating the rest of your garage.

This is where health and safety comes in. You need to be careful that whatever material you decide to use to insulate your garage is not flammable.

You might have seen at home depot or Lowes the option to use old denim jeans as a form of insulation. While this might sound appealing and you might be thinking I’ll just shred up a bunch of old clothes and wrap the interior of the garage in them. You’ve got to be careful as the product Home Depot offers will be treated with fire retardant coatings that will prevent you insulation going up in flames.

Insulation made from jeans is becoming popular

Further more, while it might sound appealing and a bit poetic to use old jeans to insulate your garage, it costs twice the price of regular insulation and has a lower R rating.

Don’t Cut Corners on Insulation

I thought about giving a bunch of quirky options that you could use to insulate your garage walls but the truth is plane old regular store bought insulation is cheap, fire safe and performs excellently in keeping your garage warm.

Given the square footage of garages is relatively low, the cost of covering your entire garage in insulation could be as low as a few hundred bucks. However this is the way I’d go.

Be Tactical Where you Place Insulation

If your budget wont swing to insulate the entire garage then there are a few shortcuts you can take.

For instance, if your garage is part of your home then chances are the ceiling is already insulated as will any wall that is connected to an interior wall in house itself. Otherwise heat would escape the home and disapate into the garage.

So in these cases you’d be insulating walls that are already insulated! My advice would be to focus on the externally facing wall and the garage door itself. That way you can spring for some good insulation that will provide the maximum amount of benefit. You can also buy a garage door specific kit insulation that is designed to move when your door does.

If you want to read a little more on where it makes sense to insulate your garage then I’ve put together several articles covering the topic in depth. I highly recommend taking a moment to read through them:

Wear A Sweater!

Sometimes the simplest solutions are the best!

This is partly me joking and partially a real way to stay warm in your garage. I mean think about it. If you’re only spending a short amount of time in your garage then do you really need to invest in lots of insulation?

Also if you live in a climate that is only cold for a few months of the year then does it really make sense to go to the efforts of insulating your garage?

Sometimes the simple solutions are the best. They may not be as interesting as digging deep into material sciences of insulation but they can and do work!


Can you insulate your garage cheaply? Yes you absolutely can. Provided you review the air gaps in your garage and tactically place insulation where the garage would benefit from it most. Taking care to use fire safety rated and quality insulation.

If you’re on a budget then your best approach is to use your brain first and decide what approach can achieve the best results without blowing the bank. If you can do that then you stand to dramatically cut the costs associated with insulating your garage while retaining much of the gains that are associated with a well insulated garage.

Ok that’s it! I hope you enjoyed reading this article and it gave you a few ideas on how to insulate your garage cheaply. If you do have a bigger budget then I highly recommend reading our other articles on garages and garage insulation. You can check them out here.

If you think someone else would benefit from reading this then share it on social media. It helps promote the site!

All the best



Steve Foster

Suburbanite, tech geek, handy man, automation enthusiast who started blogging about the stuff I do around my home and found he had a knack for it.

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