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Can Fiberglass Insulation Touch Ductwork? [Explained]

Whether fiberglass insulation can touch ductwork is quite tricky. However, there’s obviously an answer to your problem. 

Can fiberglass insulation touch ductwork?

Yes. But only if the ducts aren’t forming an excessive amount of condensation. Or leaking for somewhere. So, use the fiberglass insulation only after inspecting the ductwork. Then cut the insulation linearly. And lay those strips on your ductwork. Lastly, just use foil tape to seal everything in place.

The whole thing is a bit more complicated than you think. 

We’ve discussed when you can actually use fiberglass insulation. Plus if the ductwork is fine, how can you install fiberglass insulation around it. 

Therefore, for your safety please continue reading! 

When Can Fiberglass Insulation Touch Ductwork?

No doubt that working with fiberglass insulation and ductwork can be quite difficult. 

But hey, did you know?

Fiberglass insulation is actually pretty great for your ductwork. Because it’s light but strong and can withstand heat too. 

Therefore, your indoor air quality will be great. Plus your home will be all safe too!

So yeah it can be said that fiberglass insulation is one of the best!

However, my friend, there’s a catch-

You can’t let the fiberglass insulation touch ductwork if it’s leaking. Because this can be quite hazardous for your health. 

Not only that- 

Using insulation during excessive condensation is also dangerous. Then loose fiberglass batts/insulation can prevent you from breathing properly. 

Lastly, the cracked and porous ductwork should be avoided too. Otherwise, your HVAC system will get damaged as well.

Therefore, only use the insulation if you don’t come across these conditions. And if there’s any problem with your ductwork, try to fix it. 

You can do it yourself. Or you can hire a professional. 

How to Install Fiberglass Batts/Insulation Around Ductwork? 

Now, if your ductwork is in good shape, start installing fiberglass insulation. To be honest, it’s not that hard! 

Therefore, let’s quickly check out what you have to do- 

Grab the Important Tools

The very first thing you have to do is get the essential tools. You’ll need some safety gear as well. 

So, let’s take a look at the tools and gear:

  • Gloves 
  • Goggles 
  • Sharp knife 
  • Foil-backed insulation wrap 
  • Foil duct tape

Now, you’ve to get these tools. Otherwise, you can’t start your work. 

Wear the Safety Gear & Prepare Yourself

So, have you grabbed all the tools we mentioned? 

Well, if you haven’t, don’t just wait! 

Because it’s time to prepare yourself for the installation process. Start wearing gloves and goggles. 

Now, we suggest wearing nitrile gloves. Because they’re better suited for work like this. You can even use them for safely putting new siding over an asbestos one

To help you out, here are some of our top picked nitrile gloves:

Product 1


Product 2


So, hurry up and get the gloves! Because it’s time to get to work. 

Cut the Foam Batts/fiberglass Insulation Linearly

Once you’re all ready, you’ve to begin slicing the foam batts. Use a sharp knife to cut it linearly. 

We suggest you use a utility knife. Here are some of our favorites:

Product 1


Product 2


Therefore, get the knife and start cutting!

Now, your foam batts might not have any adhesive to them. So, in that case, you can use foil tape. Just grab your foil duct tape and attach it to the foam batts. 

Foil duct tape is perfect for this kind of work. Because it’s heat resistant. Therefore, the adhesive won’t melt and the tape will stay in place. 

Plus, foil tape is used for connecting duct board plenums to your air handler

But if you want, a true duct sealant can be used too. And to be honest, this equipment is a pretty good choice for you.

Because foil tape can actually peel off at some point. But the duct sealant won’t. 

Place  Fiberglass Strips on Your Ductwork

Now, it’s time to lay those strips on the ductwork. Place them down one by one.

Apply a little bit of pressure while you’re doing so. Also, make sure you leave no gap between the strips. 

Therefore, pinch the fiberglass strips together to avoid any gaps. Then place another foil tape layer to seal those connecting parts. 

Lastly, remember to check whether the ductwork can still be separated and repaired. But, only if it’s needed. 

For this, measure and mark the places which have connection parts. You can try and omit your taping wherever the connection pieces lie. 

This way, you’ll be able to separate and fix the ductwork when it’s required. 

Inspect Your Fiberglass Insulation

Finally, the last part! 

Yup, you’ve worked hard till now. Just a little bit more investigation and you’re all good! 

So, after the fiberglass insulation is installed around your ductwork, inspect it. 

You’ve to make sure the fiberglass insulation isn’t loose or puffed up. Because this can cause breathing problems. How? 

Well, dangerous particles get into the air due to loose fiberglass insulation. And if you inhale this air, you’ll suffer from skin and lung irritation. Furthermore, in serious cases, lung cancer.

Now, you might think installing fiberglass insulation isn’t your cup of tea. And that’s when you hire an expert to do the job for you! 

Because a professional can be pretty helpful for this type of work. For example, you can even get your asbestos siding cut easily by an expert.  

You can also learn from them and attempt to do it yourself next time! 


Question: Is fiberglass ductwork actually safe?
Answer: Well, it’s only a problem, if the ductwork is cracked and leaking. It’s also unsafe if the ductwork forms too much condensation. Also, loose fiberglass insulation can cause trouble too. 

These conditions are harmful to you and your HVAC system. Otherwise, you can totally install the fiberglass insulation around your ductwork.

Question: Can fiberglass dust make you sick?
Answer: Yup, you can get sick. Because if you inhale fiberglass dust, you’ll first have breathing issues. Then your nose, eyes, and skin will start irritating too. Long-term inhalation can even cause lung problems. That’s why you have to inspect the ductwork before insulating it. 

Question: What’s the best insulation for HVAC ducts?
Answer: Well, fiberglass insulation is your best option. Because these can tolerate heat and keep your home safe. This insulation comes in various thicknesses as well. Also, fiberglass insulation lasts for years. 

Plus, it doesn’t cost that much. Therefore, if you want to insulate your ductwork, buy the fiberglass one. 

Question: How to wrap fiberglass insulation around ductwork?
Answer: Well, it’s pretty simple. Firstly, inspect your ductwork and insulation for leaks, dust, etc. If they’re in perfect shape, cut the fiberglass insulation into strips. Lastly, tape down those strips around your ductwork. And you’re all done! 

Take Away 

Hope you understood the points we mentioned on can fiberglass insulation touch ductwork

Did you use fiberglass insulation for your ductwork? 

Good luck figuring out if you want fiberglass insulation or not!