Are Insulation Boards Flammable? Understanding Fire Safety in Insulation Materials
If you’re picking insulation for your home or a job site, fire safety isn’t just a fine-print detail—it’s something you need to think about up front. I’ve been in this business since bell bottoms were still in style, and let me tell you: not all insulation boards are created equal when it comes to handling heat.
So, are insulation boards flammable? Well… some of them absolutely are. Others? Built like a fireman’s jacket. Here’s the no-fluff rundown on the main types we work with, and what you need to know to keep your space safe.
1. Polyisocyanurate (PIR): The Overachiever With a Caveat
PIR boards are stiff, high-performance foam panels—popular in walls, roofs, and anyone looking for big R-values in a slim package.
🔥 Will it burn? Eventually, yes. PIR boards are less flammable than other foam boards because they’ve got fire retardants baked in. They tend to char instead of going up like a tiki torch. But hit them with serious heat, and they’ll still catch and send off toxic smoke.
✅ What to do: Always cover PIR with a fire-rated barrier—like drywall. Never leave it exposed in finished spaces.
2. XPS: Tough Against Moisture, Not Against Flame
Extruded polystyrene (XPS) is what you’ll find behind a lot of foundation walls and under slabs. Great for water resistance, not so great for fire.
🔥 Will it burn? Like dry pine in August. Even treated XPS can ignite and gives off thick, nasty smoke when it does.
✅ What to do: XPS should never be left uncovered indoors. Wrap it up tight behind something non-combustible—gypsum board is your friend here.
3. EPS: Cheap, Light, and Quick to Catch
Expanded polystyrene (EPS) is kind of the little brother to XPS—lightweight, inexpensive, and used in packaging, walls, and roofs.
🔥 Will it burn? Oh yeah. Faster than XPS, in fact. It’s got a lower melting point and will absolutely feed a fire if you let it.
✅ What to do: If you’re going to use EPS, bury it completely behind non-combustible materials. Think of it like kindling—treat it with caution.
4. Mineral Wool (aka Rockwool): Built From Lava, Basically
Now we’re talking. Mineral wool is made from spun rock and industrial slag. It’s dense, durable, and basically fireproof.
🔥 Will it burn? Not a chance. It’s non-combustible and holds up to temps north of 1,800°F. I’ve seen it used in fire-rated assemblies, and it doesn’t even blink.
✅ What to do: If fire resistance is your top concern, this is your MVP. No special treatment needed—install and sleep easy.
5. Fiberglass: The Old Reliable (With a Caveat)
Fiberglass boards are another non-combustible option made from—you guessed it—glass fibers. Great for ductwork, ceilings, and wall cavities.
🔥 Will it burn? The glass itself won’t. But if your board has a kraft paper or foil facing? That can ignite if exposed to flame or heat.
✅ What to do: Keep faced fiberglass away from open flames, light fixtures, or anything that gets hot.
Fire Safety 101 (From a Guy Who’s Seen Some Things)
Whatever insulation you’re working with, there are a few universal rules that’ll keep you out of trouble:
✔ Cover your foam. XPS and EPS should never be exposed in a finished space. Always wrap ‘em up in drywall or cement board.
✔ Know your codes. Every town has its own rules. Follow your local building codes like your roof depends on it—because it does.
✔ Vent properly. Trapped heat can turn a safe attic into a fire trap. Good airflow helps prevent that.
✔ Install smoke detectors. Especially near new insulation work. Cheap insurance.
✔ Use fire-rated products when you can. Mineral wool and fiberglass might cost a bit more, but they’re way safer in a pinch.
So… Are Insulation Boards Flammable?
Some are. Some aren’t. If you’re using foam—like XPS or EPS—just assume it burns and plan accordingly. If you want the peace of mind that comes with fire resistance, mineral wool or fiberglass is the way to go.
And if you're not sure what makes sense for your home? That’s why we’re here. At Nealon, we’ve been insulating Connecticut homes since 1977. We know the products, we know the codes, and we know how to do the job right the first time.
📞 Give us a shout if you’ve got questions or need a quote. We’re happy to walk you through your options—no pressure, no BS. Just honest advice from folks who’ve been doing this for nearly 50 years.
Let’s make sure your insulation does its job without becoming a fire risk.
Related Articles
How to Price an Insulation Job (Straight from the Contractor’s Notebook)
If you’ve ever gotten a quote for insulation work and thought, “Where is this number even coming from?” — you’re not alone.We get it. Home improvement pricing can feel like a black box. So let’s open it up. This post breaks down how insulation pricing works — at least for us at Nealon Insulation — so you can make better-informed decisions about your home.
If you’ve ever gotten a quote for insulation work and thought, “Where is this number even coming from?” — you’re not alone.
We get it. Home improvement pricing can feel like a black box. So let’s open it up. This post breaks down how insulation pricing works — at least for us at Nealon Insulation — so you can make better-informed decisions about your home.
The Building Blocks of a Quote
Every insulation project has three core pricing components:
- Materials
- Labor
- Margin (which covers overhead as well as a modest profit for us… we gotta eat too!)
Let’s break each one down.
1. Materials: What You’re Putting in the Walls (or Attic or Basement)
First up: materials. This part’s pretty cut and dry.
Based on the size of the space and the type of insulation you need — fiberglass batts, spray foam, cellulose, etc. — we estimate how much product is needed based on the square footage and necessary R-value which is essentially measured by thickness in inches.
We know the cost per bag, batt, or board foot (square foot by inch) of material. Multiply that by the quantity needed, and you’ve got your material cost!
Simple as that! It’s transparent and straightforward — no magic here…
But next come’s the trickier part…
2. Labor: Who’s Installing It, and How Long will It Take
This is where things start to vary a bit more.
We do our best estimate how many total hours it will take to complete the job, from setup to cleanup. Then we multiply that by the average hourly labor cost across our crew. Our goal is to be as efficient as possible with this to ensure that you don’t get overcharged and everyone comes out a winner.
But it’s important to note labor isn’t just the physical act of installing insulation. It includes things like:
- Driving to your property
- Setting up tools and safety gear
- Protecting your home’s surfaces
- Cleaning up so you’re not left with a mess
If your home is older, has tight crawlspaces, requires extra prep, or needs just a little bit more concentration and caution then of course the labor hours go up.
And on top of that in this line of work sometime’s we’re getting into spaces or walls where we don’t even know what we’re going to find until we’re in there so sometimes contingencies need to be built in.
3. Margin: Why the Final Price Isn’t Just Materials + Labor
Here’s the part most people don’t talk about — the markup…
After we calculate materials and labor, we add a target margin. This isn’t just profit for us. It also covers all the other costs of running a business:
- Insurance and licenses
- Vehicles and gas
- Payroll taxes
- Tools and equipment maintenance
- Office support
- Marketing and scheduling
- Training, safety, and more!
But I promise we’re not greedy! Our goal is for you, the customer, to get real value for the price. We don’t aim for crazy margins. We aim for healthy, sustainable ones — the kind that keep good, high quality people employed and happy to help you with your problems.
Why Some Quotes Are Lower (or Higher)
If you see a big discrepancy in pricing, it could be because:
- They’re cutting corners on material quality
- They’re underestimating labor time
- They’re not factoring in overhead (and may not be around next year)
- Or maybe they’re just a more efficienct company
If a quote is higher, it could be due to a company’s inefficiencies, higher overhead, maybe just plain greed… or maybe they’re higher quality and doing things the right way.
Everything’s relative here so it’s hard to know, just make sure you’re working with someone you can trust and know what you’re paying for.
Final Thoughts
Insulation isn’t glamorous, but it’s one of the best investments you can make in your home’s energy efficiency, comfort, and long-term health.
We believe in doing things right — pricing included. When you get a quote from us, it’s built through real time, effort, and deep thought to ensure we’re providing the highest quality work for the best value:
Materials + Labor + Margin = Total Price
It’s not rocket science. It’s just good business.
And when it’s done right, everybody wins.
👉 Free consultation. No pressure. Just honest advice.
How Much Money Will I Really Save by Upgrading my Insulation?
Let’s be honest—insulation isn’t sexy. It’s not something you show off to your neighbors. It’s not your renovated Kitchen with marble finishing or a beautiful new stone deck with a built in grill and smoker.
Let’s be honest—insulation isn’t sexy. It’s not something you show off to your neighbors. It’s not your renovated Kitchen with marble finishing or a beautiful new stone deck with a built in grill and smoker.
No one’s coming over to crack open beers and admire the craftsmanship… “Wow, check out that R-49 blown cellulose! There’s no lumps or anything!”
But… if you own a home in Connecticut, insulation might be the most boring way to save yourself the most money. You won’t get oooh’s and aaah’s but you will get lower energy bills, a more comfortable home, and fewer fights over the thermostat.
But I know what you’re now asking yourself… how much can I really save? How long does insulation take to pay for itself?
🥁🥁🥁
The Short Answer: 2 to 5 Years…
The Even Shorter Answer: It depends! But it does works
But definitely don’t take my word for it. What do I know, I’ve only been doing this for 40 years… And I’ve been told I’m biased or something…
Let’s see what the Research Says
According to the U.S. Department of Energy (DOE) and Energize CT, insulation and air sealing will shave 15–30% off your heating and cooling bills. In Connecticut, where winters are long and heating oil is basically liquid gold, that adds up!
- The average Connecticut household spends around $2,000 per year on heating and cooling combined (source: EIA.gov).
- So let’s do some quick math!
- If you saved 20% on your heating and cooling bills that’s $400/year back in your pocket.
- If your insulation project costs around ~$2,000 that’s about a 5 year payback
- If you save closer to 30%...that’s less than a three and a half year payback
- After that it’s just continuous money in your pocket for the next 25-30 years until you need another upgrade
But like I said before… it depends!
Not to brag or anything but we’ve upgraded homes in which the payback period was fewer than 2 years!
Add in Connecticut’s Home Energy Solutions program, and it gets better. The program can often cover up to 75% of the cost through rebates and incentives.
Facts, Myths, and We-Just-Don’t-Know
There’s a lot of information floating around out there...let’s break it down.
✅ Facts
- Insulation reduces energy bills.
- This is backed by the DOE, ENERGY STAR, and pretty much anyone who’s upgraded their insulation and compared their before and after their utility bill afterward.
- This is backed by the DOE, ENERGY STAR, and pretty much anyone who’s upgraded their insulation and compared their before and after their utility bill afterward.
- Air sealing matters. A lot.
- Think of it like this: insulation is your sweater. Air sealing is zipping up your jacket. Both are good. Together, they’re great.
- Think of it like this: insulation is your sweater. Air sealing is zipping up your jacket. Both are good. Together, they’re great.
- Rebates are available.
- Older homes in CT are often wildly under-insulated.
- Especially if they were built before 1980. Some wall cavities are literally empty.
- Especially if they were built before 1980. Some wall cavities are literally empty.
❌ Myths
- “Insulation only helps me in the winter.”
- Nope. It helps in summer too by keeping heat out and ensuring more efficient AC use. Ever been in an attic in July? If so, you get it.
- Nope. It helps in summer too by keeping heat out and ensuring more efficient AC use. Ever been in an attic in July? If so, you get it.
- “If I have insulation, I’m good.”
- Maybe. But maybe not. A lot of homes have insulation that’s:
- Just not enough
- Poorly installed
- Degraded over time
- Maybe. But maybe not. A lot of homes have insulation that’s:
- “It’s too expensive to be worth it.”
- With rebates and long-term savings, insulation’s one of the few home upgrades that pays for itself—and then keeps paying.
- With rebates and long-term savings, insulation’s one of the few home upgrades that pays for itself—and then keeps paying.
🤷♂️ We Just Don’t Know
- Exactly how fast your home will pay it back.
- We need to see the place. Every home is different. We’ll look at square footage, current insulation levels, energy bills, and then we can estimate savings and rebates.
- We need to see the place. Every home is different. We’ll look at square footage, current insulation levels, energy bills, and then we can estimate savings and rebates.
- How much longer Connecticut winters will get.
- Between polar vortexes and mild Decembers, who knows. But insulation helps regardless.
- Between polar vortexes and mild Decembers, who knows. But insulation helps regardless.
- Why builders didn’t insulate better in the '60s and '70s.
- Your guess is as good as ours. Maybe they just loved single-pane windows and cold feet.
- Your guess is as good as ours. Maybe they just loved single-pane windows and cold feet.
Final Thoughts
Insulation’s not flashy. It’s not fun to talk about at parties (...actually it is for us). But in terms of bang-for-your-buck, it’s one of the best home improvements you can invest in.
Here’s what you get:
- Real savings
- Real comfort
- A more efficient, quieter, and healthier home
If you’re in Connecticut, you’ve got access to generous incentives. We’ll even help you apply for them. So if your house is cold, drafty, or your energy bills are making you sweat—get in touch.
👉 Get in touch with Nealon Insulation. We’ll take a look, give you honest feedback, and let you know if it makes sense. No pressure. No BS. Just real talk, real results, and real insulation.
Why Does Insulation Lower Your Energy Bill?
Let’s start with this: insulation isn’t just a nice-to-have—it’s one of the most cost-effective ways to cut down on your energy bills year-round. Whether you’re battling a New England nor’easter or a brutal summer heatwave, your insulation is doing the quiet, thankless job of keeping conditioned air where it belongs: inside your home.
Let’s start with this: insulation isn’t just a nice-to-have—it’s one of the most cost-effective ways to cut down on your energy bills year-round. Whether you’re battling a New England nor’easter or a brutal summer heatwave, your insulation is doing the quiet, thankless job of keeping conditioned air where it belongs: inside your home.
But how does it actually save you money? Let’s break it down.
1. Insulation Slows Down Heat Transfer
Heat moves in and out of your house constantly—through walls, ceilings, floors, and anywhere it finds a weak spot. This process is called heat transfer, and without good insulation, your home is bleeding energy like a sieve. In winter, warm air escapes. In summer, heat pours in. Insulation acts like a barrier, slowing that process down so your HVAC system doesn’t have to work overtime to keep up.
Less work for your furnace or AC = less energy used = lower utility bills.
2. Insulation Keeps Temperatures Stable
Ever notice how some rooms feel freezing while others are sweltering? That’s usually a sign of poor insulation or air leaks. Ideally, rooms in the same house shouldn’t differ by more than 2–3°F. If you're seeing 5 degrees or more between rooms, it’s a red flag—your home likely has insulation gaps or airflow issues.
When you insulate properly—especially your attic, walls, and basement—you even out those swings and stop playing thermostat whack-a-mole. Want to layer your savings? Combine good insulation with simple, low-cost hacks to stay warm in winter—like these 10 free or cheap ways to stay warm.
3. It Reduces HVAC Runtime
Your heating and cooling systems cycle on and off all day. But the better your home holds its temperature, the less often those systems need to run. Over time, this adds up to serious savings—not just on energy, but also on maintenance and equipment lifespan. Well-insulated homes put less wear and tear on HVAC units, meaning fewer breakdowns and a longer system life.
4. It's a One-Time Investment That Pays Off For Years
Insulation isn’t a band-aid fix—it’s a long-term upgrade. Whether you’re using spray foam, batts, or blown-in cellulose, you’re making a one-time investment that keeps paying you back every month.
And if you’re looking to insulate finished walls without tearing everything apart, we’ve got a method for that too. It’s called drill and plug, and it lets us dense-pack cellulose insulation from the outside of your home—sealing up energy loss while leaving everything looking untouched. It’s one of our go-to moves for older homes with empty wall cavities.
The Bottom Line
If your energy bills are creeping higher and your home still doesn’t feel comfortable, your insulation might be the culprit. Fixing it won’t just make your house cozier—it’ll put money back in your pocket every single month.
Want to see what better insulation could do for your home?
👉 Get in touch with Nealon Insulation. We’ll take a look, give it to you straight, and help you lower your bills the smart way.
Let's Work Together
Ready to transform your home into an energy-efficient haven? Schedule your free energy assessment today and experience the Nealon difference for yourself.