Old Insulation Types: All You Need To Know

Deciding whether or not to invest in house insulation is not only about how much money you need and what is the best option for reinsulating your home. It’s not only about how much money you will manage to save on electricity bills and make a more comfortable living space. You also need to think about the old insulation, the one that already exists on your walls because this might be a bigger problem than you suspect.

The fact is, when deterioration of existing insulation becomes visible it's obvious you need to start thinking about investing in new insulation. But the trick is that some aspects of bad insulation might not be visible and can do much harm, like endangering the health of the homeowner and his family. So it is quite important to understand old types of insulation and how they work.

Early building insulation materials

The evolution of insulation is quite interesting, and it is fascinating to see where we started and with what methods, and where we are today. In ancient times mud was the number one insulation solution - Egyptian people chose it for insulating pyramids, but at that time the viable options were also fur, animal skin, straw, reed, etc.

Then there were Greeks who started using asbestos, and it was such a revelation, especially asbestos batt insulation. But later on came rock wool and it's still a decent option for home insulation. The old rock wool insulation is super efficient when it comes to keeping the temperature of a house consistent, but also it is a great sound barrier and it can come in batts, rolls, boards, loose-fill, or blanket shapes.

The next in line of most popular insulation options is vermiculite - a lightweight natural mineral that's usually inserted between ceiling joists. We already established that vermiculite is often mixed with asbestos, which makes it harmful, even though the material on its own is a safe insulation option.

Today, the most common insulation material is fiberglass, an insulator that was created by accident in 1932. Even though it is used very often, and in a DIY manner by many homeowners, there are dangers of fiberglass insulation during the process of installation, which is why it is essential to wear proper protective gear when placing it. That’s because microscopic parts of glass slivers may irritate our throat and skin.

But besides fiberglass, some other insulation materials are quite popular today - cellulose, foam, as well as 48-inch Prodex or 24-inch Prodex. What’s important to point out is that buildings in the United States that were built before 1965 didn’t have to have insulation, so most of them don’t, or if they do they are covered with old types of house insulation.

Dangerous Insulations

Not only your insulation might not be effective anymore, but you may be exposed to some toxic aspects of living in a house with old insulation. These are the types of old insulation and all the dangers you may face for living in badly insulated homes:

  • Asbestos

The number one dangerous insulation is definitely asbestos insulation. In most states, it’s now forbidden to use this type of insulation, but the reality is you will find it in many old homes. And it is a huge problem because asbestos can cause several serious health conditions, it can lead to lung cancer, mesothelioma - another type of cancer that attacks the tissue around the stomach, lungs, heart, and other organs, asbestosis - a chronic lung issue, and some other diseases.

Bear in mind that asbestos insulation can be found in most homes built around 1900 and that it can be an endangering factor if damaged, but also if removed or moved in an improper way and without the proper protection. So do not re-insulate your old home covered in asbestos insulation by yourself by any means, let the professionals do it the right way.

  • Vermiculite

This is another type of material that can be a health hazard, and it is present in many old homes. We are talking about vermiculite which was a very popular insulation option back in the day, and a very widely used one as well. If you are wondering what does vermiculite insulation looks like, it’s very easy to recognize it - it appears like loose gravel.

Now, it is important to understand that vermiculite is not toxic on its own, it is a natural mineral that absorbs moisture and has great insulation abilities, but in most cases, it was contaminated with asbestos, which makes it a dangerous option if used for wall insulation for instance. In the past vermiculite was taken out of the same mines where asbestos was produced, which resulted in its contamination.

  • Urea Formaldehyde Foam

When it comes to urea formaldehyde foam the usage of this material is another reason to worry about the dangers of insulation, but it is not that often to see it these days. That’s because the urea formaldehyde foam was usually used for insulating homes in the 1930s. It’s super simple to recognize it given it has a distinct yellow color, and it looks like a liquid that was frozen in a moment.

At some point, it was established that when urea formaldehyde foam gets to the curing process it emits formaldehyde vapors, and these vapors can negatively affect our health by impacting mainly our respiratory systems. So when re-insulating a home with this type of old insulation it would be best to leave it to professionals, just like in the previous two cases, to lower the chances of being exposed to this damaged and toxic material.

How to identify what type of house insulation do you have?

But what does old insulation look like, and how to recognize it’s time for a change? It’s easy, all you need to know is what’s behind the walls. We are now going to present what all popular insulations look like in their healthy state, so when you establish the type you just need to see what’s the state of the insulation. That should be a clear clue on whether or not it is time for a change.

Fiberglass - it has small, fine glass fibers and it comes in yellow, pink, green, or white color. It should be spongy when you touch it. Sometimes, when it comes in panels and batts it can be wrapped with foil or paper.

Cellulose - it’s made mostly out of recycled paper. It can be rocked shaped or in the form of a liquid when installed, and later on, it looks like shredded gray paper, but the mash might be also white or beige.

Fast Action Prodex Total - this is a thin, shiny silver foil that has adhesive on one side. It comes in rolls. When you look at its intersection you will see a lot of tiny white bubbles that are glued together with a transparent substance.

Mineral wool - this is another recycled material that contains a great percentage of post-industrial recycled materials. When in good shape mineral wool will look like a homogeneous gray or beige mash. It should be spongy and soft when you touch it.

Polystyrene - this particular material is fully transparent or whitish, and it can be solid or foamed, depending on the form in which it was placed. It should be hard to the touch, not fluffy, and with sharp edges, if placed in panels. When sprayed it will be bumpy but also hard.

Best insulation for older homes

At this point, you know you have some bad old insulation inside your home walls and you need to replace it. We hope we were clear when advising you to get professional help with this project if your home is covered with asbestos insulation or any other dangerous type we mentioned above.

But what are the best solutions for old homes? We suggest you go with fiberglass or cellulose insulation, given these are not too expensive options and they both have great energy efficiency rates. The advantage of cellulose is that it is eco-friendly but its installation may cost you a bit more.

Also, rigid foam panels are a good idea, but if you are about to use them for the interior insulation know they must be covered with drywall in order to be fire-retardant. 16-inch Prodex Total is another great solution given this material is unaffected by humidity, prevents condensation, and stops 98% of radiant heat transfer - it is a great option for crawl space insulation.

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