Fire resistant insulation - Rockwool

Can Rockwool Insulation protect a house from Fire?

Foreword by Ian Thompson, Editor

As part of our series of videos and articles discussing the advantages and disadvantages of different insulation types, Matt discusses Rockwool insulation, a product he uses quite often in his new house builds in Texas, USA. Rockwool is relatively unknown in New Zealand, where I live, yet it seems a highly effective insulation material, boasting exceptional fire protection properties and offering an added layer of safety to your home that is often overlooked by designers, builders, and specifiers.

Rockwool insulation, or mineral wool insulation, holds its own when compared to some of my preferred insulation types like cellulose, expanded polystyrene (EPS), and natural insulation materials. Each of these materials has unique characteristics, advantages, and considerations, but none are perfect – there is always a compromise.

Cellulose insulation, primarily made from recycled paper, is an affordable and highly sustainable option with a high R-value. It is safe to handle, with no off-gassing of harmful chemicals. However, it can absorb moisture, which might lead to potential mold issues if the house isn’t built well, which we know is a major industry problem. It must be stressed that no matter how good a product is, if the house or building isn’t built properly, then all the benefits and investment of any product fly out of the window.

I’ve used EPS in my own builds too. It is a lightweight, strong, and affordable foam insulation with good thermal resistance. It’s resistant to water damage and doesn’t support mold growth. However, being petroleum-based, it’s not as sustainable as cellulose or natural insulations, and might pose environmental concerns.

It must be stressed that no matter how good a product is, if the house or building isn’t built properly, then all the benefits and investment of any product fly out of the window.

Ian Thompson, Editor

Natural insulation materials, including wool, cotton, and hemp, are often biodegradable and made from renewable resources. They provide good insulation, are safe to handle, and don’t off-gas harmful chemicals. Nevertheless, these options are typically more expensive than synthetic insulations, which puts a lot of buyers off natural insulation like wool.

Compared to these, and as Matt discusses, Rockwool insulation offers superior fire resistance due to its rock and mineral composition. It’s also excellent at soundproofing and is durable over time. Cost-wise, Rockwool might be slightly more expensive than traditional fiberglass or cellulose insulation but offers good value considering its benefits, and depending on where and how you buy it!

In terms of health considerations, Rockwool is generally safe to handle, although proper personal protective equipment should be used during installation to prevent potential skin or respiratory irritation. If left exposed in an area like an attic, a layer of drywall or similar material can be used to reduce potential contact, especially if it’s a space you use from time to time.

When considering sustainability, Rockwool is made from naturally occurring, renewable raw materials, and its long lifespan contributes to energy efficiency by reducing heat loss. However, its manufacturing process is more energy-intensive compared to other types.

I’ll leave it to Matt to take you through his experiences using Rockwool insulation in his builds. It’s an old video but still relevant today. Over to Matt:

Can Rockwool Insulation protect a house from Fire?

Matt’goes LIVE on Dallas’s Good Morning Texas to put Rock Wool to the test!

Huge thanks to Ovilla Fire Dept. you guys are awesome!

Video Transcript:

Recent fires in California might have you thinking about how to protect your home if a fire breaks out. This morning, Alana is live checking out environmentally friendly insulation that can help protect your house. It’s for Rock Tool Fire and Soundproofing Insulation, and she is live in a villa.

“Morning, Alana! That’s where I am today. I am all dressed up because we have a large fire here, and I’m joined by my guest, Singer. He’s a builder and a YouTuber. What’s going on over here, man?”

“We’ve got a massive burn going on today. We’re doing a demonstration for fire safety. What we’ve got here is this giant flame. On top of that is some stone wool insulation. We made a birdhouse, and inside the birdhouse is a box of chocolates just like this. This box of chocolate right now is already warm, kind of been near the fire. What was the fire? That’s right, and you know, we’re in Texas. A box of chocolates left in your car for very long can get hot and melt. We’re gonna see what happens after this fire goes for a few more minutes to this box of chocolates.”

“Well, we’re talking about fire safety in your house. The most important thing to keep your family safe is your smoke detectors. These smoke detectors are your first line of defense. A couple of things you need to know about smoke detectors, though: change your batteries once a year when we fall back once a year and change those. You need to change your batteries. The other thing you need to know is these have a limited lifespan, about ten years before you need to change your smoke detector itself. Nest has a brand new one in the marketplace. This one will also detect CO levels in your house and send an alert to your phone. Good tips to know and a nice reminder in case we need to check those batteries or even just replace altogether.”

“Now, remind me what this insulation is made out of here.”

“It’s actually made of these rocks. That’s right. So, this stone wool insulation that’s happening to be made by rocks. All this is made from rocks. We’ve got two kinds of rocks here, and most of this is actually recycled content from the steel industry. So, we’ve got a good recycled story here. But a couple of other benefits besides fire resistance to this, it also is great for soundproofing. So when remodeling your house, we’re gonna give, by putting this insulation in, we’re gonna give your family precious time, as you’re gonna see from this demonstration, to get out of the house for the firefighters like these great guys that Ovilla to get in there and protect your house, put that fire out. And it also has some water properties as well. Look at this one that’s been soaking in water. Just runs right off like water off a duck’s back. Very impressive.”

“You mentioned moments, the seconds because you’re down to the second. That really is very important to get everybody out and get everybody to safety.”

“That’s right. So a bunch of things combined are gonna give your family that extra time, and this insulation’s gonna be a big part of that fire safety strategy.”

“It’s time to check in on our chocolate. And so, we’re gonna have Kevin from Ovilla Fire Department go ahead and put this fire out so we can check inside the fire cage. And so, you’re telling me inside that birdcage of insulation, there is a box of chocolates, and it is not going to be touched. We’ll see. We’re about to find out. That’s a pretty visible demonstration. That fire looks pretty hot to me. They’re gonna bring it over here too because I don’t want to touch it. You haven’t, that’s for sure. These guys have all the protective gear. Alright, so there’s our box of chocolates. It was in there the entire time. Let’s have a look. Thank you, sir.”

“And look at that! You know, dare me to try because I kind of want to, even in Texas, you can barely leave chocolate in your car without it melting, and you fire… a perfect demonstration to show you how this is going to help protect your family, give you time to get out of the house, you and your loved ones, and of course, get the good guys from Ovilla Fire Department there to put out the fire and protect your structure. This is ideal for those who might be building or building their home right now. But where can somebody go for more information or to look into the installation a little more?”

“That’s right. So, you can buy this Rockwool insulation at your local Lowe’s and Home Depot, and of course, talk to your builder like me about using this type of insulation in your house. This is stone wool with information one more time. The website for these guys is, and of course, you can get this locally at Lowe’s or Home Depot.”

“You heard it here! Start for yourself. We have witnessed a fire, the end your time. No tricks, no magic, no nothing. The chocolate has not melted whatsoever. Matt, thank you so much for the good information. Jane, I’ll toss it back to you.”

Asthma New Zealand Healthy Homes Series – Episode 2 – Insulation

External Youtube related post: 7 reasons I used Rockwool insulation at my house.