How To Insulate An Existing Metal Building? 3 Awesome Methods!

Do you want to know how to insulate an existing metal building? If not, then you’re just in the right place; I’ll teach you how in three straightforward methods- by a radiant barrier, spray foam, and fiberglass sheet.

Indeed, if you have a detached garage at home, it doesn’t usually come with insulation.

In fact, some regions don’t require insulation.

But, here are just some of the reasons why you should do so:


Why Should You Insulate A Metal Building?

First, it ensures comfort while you’re inside the building.

If your place has a high level of humidity, it can help reduce the accumulation of moisture below the roof; and that means the things inside the building will less likely become damp.

Of course, you should also expect that insulation comes with significant drawbacks; and one of which is “it’s not FIRE RESISTANT!”

So, the best thing to do is to take precautionary measures, especially if there are combustible or flammable items inside your metal building.

Take note of this:

The metal building itself is naturally resistant-from fire; adding insulation changes that, though.

Without further ado, let’s get into details on how to insulate an existing metal building.


Methods Of Insulating An Existing Metal Building

In this article, we’ll teach you three of the primary methods of how you can insulate your existing metal building.

Here are the following:


Method #1. Install radiant barrier insulation

This kind of insulation is typically installed while constructing the structure.

So, what does that mean? Can you still use this method if you already have a metal building?

Here’s the thing:

This insulation is placed on the building’s exterior panels found between the support beams and the panels.

It only means that you can use the method, though you still need to execute minor repairs.

Here’s how installing radiant barrier insulation is done:


Step #1. Placing the double-sided tape in the frame’s studs

After constructing the building frame, put the double-sided tape on its studs (from the top to the foundation).


Step #2. Attaching the insulation

Now that there’s a double-sided tape attached to the studs, you can now put the insulation roll therein.

Do not forget to tape the scrim of the insulation together on the white side.


Step #3. Finishing touches

Now, you’re in the final step!

It’s time to put the wall panels and screw them through all the layers into the building’s frame.


Method #2. Install spray foam insulation

Perhaps, the major advantage of this kind of insulation is that it doesn’t hold any moisture; there’s no way the things inside your building will get damp.

It’s the best option if you’re living in colder climates.

Why so?

It can, of course, insulate your building, allowing heat to trap therein.

Aside from that, it gives protection against drafts and insects.

More amazingly, it’s quick to install; and here are the steps on how to do it:


Step #1. Distribute the insulation

Get a pressurized device, and use it in distributing the insulation uniformly.


It will be challenging to remove the foam once it hardens. So, you better avoid accidental spills.


Step #2. Focus on necessary areas

Aside from the uniform distribution of foam, you also need to check on critical areas- between the studs.

Ensure that they are entirely covered (you will know that this process is complied with if it gives you optimum insulation).


Step #3. Wait

Now, it’s time for you to wait. Just be patient, okay?

Once the foam dries, you can hang the wall sheeting inside.

As easy as that!


Method #3. Install fiberglass insulation

Experts say that this kind of method is not suggested for your metal garage.

Here’s the main reason why:

It’s prone to moisture, and there are some issues regarding the stud’s spacing.

Anyway, you still have to know what insulation this is.

The typical width of a rolled fiberglass is from 15 to 24 inches.

It only shows that it’s ideal to use in wood framing studs, mainly for residential housing.

Most of the time, the frame of metal garages comes with 4 feet to 5 feet studs.

Given the added distance, you have to leave the rest for the tape.

And when the tape is used for insulation, it’s prone to peels, leaving gaps therein.

That being said, fiberglass rolls are known for holding and collecting moisture, so your building will be prone to molds.

Anyway, installing the fiberglass sheet is the same as installing the radiant barrier insulation.



If you have a detached garage or an existing metal building, it’s a good idea to install insulation.

You’ve already known the reasons why you should. Obviously, it can trap heat inside your building, helpful, especially in the cold seasons.

Anyway, either of the three methods is excellent to use; the rest depends on your discretion.

Well, anyway, each method comes with pros and cons. Whatever you think is best for your building, just go for it!

Hopefully, you’ve learned the methods on how to insulate an existing metal building.

Have a great day!

Leave a Comment