Best Types of Pipe Insulation: Foam, Fiberglass, Outdoor, or Copper to Keep Water From Freezing

The invention of pipes has revolutionized the transportation of resources to your home. Whether they contain water or natural gas, your trusty pipes ensure that the substance inside is delivered safely. However, they cannot withstand the ever-changing conditions they are exposed to without a little help. That’s where insulation comes in.

Let’s walk you through the best types of pipe insulation, including foam, fiberglass, and copper.

Why do I need to insulate?

Now, you might think this is just another one of those silly innovations designed to milk your wallet. On the contrary, they perform multiple vital functions. It will save you a lot of money in the long run.

Heat/Energy Conservation

Created for this purpose, insulation effectively contains the heat within. The heat inside will fluctuate if situated in an environment with a different temperature than the pipes. In cold conditions, large amounts of heat will be lost via radiation. In turn, the heat loss will require more energy to maintain a stable temperature.

By insulating them, you save on energy expenses.

Mechanical Protection

As you probably already know, water will freeze in sub-zero temperatures. You’d think this means no supply of water. You are right, but it doesn’t end there. Water is a peculiar liquid because it expands as it turns to ice. On the other hand, metals contract as the temperature drops. The pipes can’t survive the pressure that builds up in such frigid conditions and will burst eventually. Thus, insulation also prevents the water from freezing.

Condensation Control

Particularly cold pipes will cause the water vapor in the air to condense on their surface. Though a slightly wet pipe might seem innocuous, the constant exposure to moisture will slowly corrode the metal. Insulation causes the vapor to condense on its surface and is never made of materials that can rust away. Moreover, it prevents mold formation.

Sound containment

Whatever it is that traverses to and fro within a pipe, it will emit some noise. Insulation will effectively contain the cacophony.

Safety

While you are unlikely to get frostbitten by a cold pipe, touching a scorching-hot one will severely burn your skin. In some factories, they might be transporting extremely hot liquids. Therefore, they are insulated with multiple layers to minimize the risks of a fire hazards.

It is the law

Depending on where you live, insulation might be required by the law. It might be a good idea to acquaint yourself with these legal requirements, especially if you live in colder locations.

Insulation material types

Fiberglass

fiberglass pipe insulation

Though the material is properly called glass fiber, fiberglass has become a more popular name over the years. True to its name, it comprises numerous fibers of glass bound together. Wool-like in appearance, the individual sheets are not compressed tightly together. Since it is a poor thermal conductor, the trapped air greatly enhances its insulation efficiency.

Mineral fiber

Similar to fiberglass, it is made of many bound fibers and trapped air. As its name suggests, the fibers are made of molten minerals rather than glass. Because it is inflammable, it is an excellent choice for industrial pipework.

It is important that you handle both glass and mineral fiber with care. The tiny fibers peel from the surface and may irritate your eyes and respiratory tract. Direct skin contact might also cause scratches. When handling either one, always wear a protective suit and goggles.

Aerogel

Made from silica, aerogel is the champion among all insulants. Contrary to its name, it has nothing to do with a gel. Instead, it has innumerable pores filled with air. As both silica and gases conduct heat very poorly, they can protect an object from open fire when placed between.

However, it has not been very long since its inception. It is yet to spread across the market. As such, it remains a very expensive option.

Cellular glass

cellular glass pipe insulation

Consisting entirely of glass, this insulation type is based on a myriad of small cells which are compressed together. Also known as foam glass, it can withstand high pressure and fluctuating temperatures. What’s more, it is a very long-lived and durable material.

Polyethylene

Polyethulene pipe insulation

A very flexible material, foamed polyethylene (PE) is a very common material used to insulate water pipes. It is readily available and easy to install yourself. Polyethylene is a ubiquitous type of plastic that is not known to be dangerous to humans. Thus, the installation is much smoother than that of glass or mineral fiber.

Flexible elastomeric foams

These foams are based on rubber, making them impermeable to water vapor. This quality makes them popular to use on fridges or A/C pipework. In addition, thin layers are more than sufficient to wrap around the pipes. This makes them very space-efficient.

Foam

foam pipe insulation

Also known as rigid foam, this substance is based on plastic. While it works poorly to absorb noise, it’s very heat resistant. And just like any kind of foam insulation, it saves a lot of space.

One of its variations is phenolic foam. It is a popular material mainly thanks to its high thermal resistance and space efficiency.

Polyurethane or spray foam is an alternative to phenolic foam, which sports similar qualities.

What to look for?

When you decide to insulate your pipes, consider taking the following three factors into account.

Insulation thickness

Each material requires a different layer density to apply to your pipes to be effective. If you know there is not much space wherever your pipes are located, certain materials might be too bulky to insulate them properly. Aerogel requires the thinnest coating out of all types, making it perfect for conserving space. However, it is not exactly the cheapest. Foam insulations are the next best contenders for this role.

Material

Choosing the correct material is crucial when insulating your pipes. While common water pipes do well with various types, specific appliances such as A/C or furnaces work best with one specific type.

Location

The location of your pipework also plays a part in choosing the right material. Ones lurking within the walls of your house are much better protected since there already is insulation in the walls themselves. On the contrary, outdoor pipes are prone to damage if you leave them bare.

R-value

When buying insulants, you might come across this term. The R-value, or resistance to heat flow, is a physical property of a material. Don’t worry, though. We won’t bore you with complicated formulae. Suffice to say that the higher the value, the higher the thermal resistance. The recommended value depends on your geographical location and the place where the pipework is situated in your house.

By function

Wouldn’t it be so easy if you could settle for one type of insulation, one ultimate winner? Unfortunately, it does not work that way. Each material has its pros and cons, and which one you should opt for depends on the function.

Water pipes

When it comes to water pipes, there are several options to choose from. Considering that the water running through them is either hot or cold, you should use versatile materials that can handle both extremities. Both fiberglass and mineral fiber insulation work well here. Polyethylene or phenolic foams are good options as well.

In case you are indecisive, it might help to know that foam-based insulation is generally cheaper than fibrous one.

Before you make the final decision, check the following sections. Your pipe material plays a big part in determining which insulation type to opt for.

Outdoor

The biggest enemy of outdoor pipes is cold. To prevent your water from freezing, we recommend using foam insulants. Be they made from PE or rubber. They will provide adequate protection for your outdoor pipes.

Stove

Producing great amounts of heat, insulation is necessary for stoves to prevent energy losses. In addition, the high temperatures might sometime melt off the plastic from nearby cupboards.

Although fiberglass was a ubiquitous material used on stoves, it is being pushed out by mineral wool. Alkaline earth silicate wool is one of its variants, and it contains heat far better than fiberglass.

Copper

When lead pipes were banned because of their toxicity, copper stepped into the shoes of the most prevalent material used for water pipes. However, it did not solve every problem. Metals are excellent conductors of heat, so they draw it out of the water and radiate it into the environment. Since both cold and warm water passes through, numerous materials might be used.

Fiberglass is one of the most popular materials for insulating your copper pipes. Not only does it stabilize their temperature, but it also contains sound. It also goes easy on your wallet.

Mineral fiber works just as well as fiberglass. Though slightly costlier, it is much more compact and space-efficient.

Polyethylene foam is another great choice to use on these pipes. Affordable and efficient, you will be able to install it with ease. They have a horizontal slit across each tube, so you slide it onto the pipe.

For outdoor copper ones, we recommend opting for rubber-based materials. It is quite sturdy and doesn’t cost much. It also handles the adverse conditions of the outdoors far better than other materials, particularly the cold.

PEX

PEX is a common abbreviation for cross-linked polyethylene. This type has been gaining momentum in the US over the years, slowly rendering metal obsolete.

With that being said, these plastic ones are most widely used to distribute potable water. Since plastic melts when exposed to high temperatures, it is unfit for industrial use.

As far as their cold resistance is concerned, they can handle lower temperatures to an extent. However, you still need to prevent freezing. You might want to consider insulating them if they happen to be outside and you live in a colder climate.

Furthermore, this extra precaution step will save you a bit of money on energy bills.

If you use PEX outdoor, you definitely need to insulate them. UV rays break down the polymer, which results in leaks.

Since cold is the primary reason for concern, we recommend that you wrap them in foam-based insulation. Because it contracts and expands according to the temperature, much like PEX, they’re a match made in heaven.

PVC

Polyvinyl chloride pipes have also enjoyed growing popularity in recent years. As a type of plastic, it contains heat with greater efficiency than metals. Despite this, your PVC should be insulated to diminish heat losses further.

Just like with PEX, foam insulants work marvelously with these pipes.

CPVC

Chlorinated polyvinyl chloride handles heat better than its non-modified version. For this reason, it is used largely near water heats. Though it will not melt, the legislation still demands that you insulate it to minimize burn accidents. Polyethylene foam and fiberglass are both prudent choices.

A/C

Closed-cell rubber foams were made to prevent condensation when the pipes are exposed to low temperatures, so they are the most prevalent material. Polyethylene or fiberglass are also used for ducts and vents like those found in shopping malls.

Rubber

Rubber tubing and hoses do not require insulation.

How to insulate pipes

Can’t quite wrap your head around the installation itself? Don’t worry. We will walk you through the steps.

For DIY installations, foams are very beginner friendly. Unlike glass or mineral wool, they are not known to be harmful to humans when handled. Thus, we are going to focus on them.

Once you’ve chosen the material, it is time to decide whether you go for wrap-based or sleeve-based insulation.

Wrap insulation

This form of insulation works wonders in places where the pipes twist and bend endlessly. It comes in thin sheets of foam.

  1. Duct tape on the end of the wrap to the pipe. The modern version might feature adhesive ends.
  2. Wrap it around the pipes in a continuous spiral. For maximum efficiency, make sure the adjacent loops overlap.
  3. When the strip runs out or once you cover the entire pipe, tape the other end to the pipe. Make certain you left no gaps.

Foam pipe sleeves

Whether plastic or rubber, these sleeves are long hollow tubes with a slit on one side. This form is ideal for longer pipes, and the installation is very simple.

  1. Open the slit and slide the tube onto a pipe. It will wrap around once you let go.
  2. Seal the slit with duct tape. To achieve this, apply the duct tape horizontally along it. Modern sleeves might feature an in-built adhesive in the slit. If so, simply seal it shut.
  3. Apply as many sleeves to them as needed. Make sure you tape all the ends of two adjacent sleeves.
  4. When you reach the end or a turn, cut the sleeve short. Consider using wraps for the turns.

Asbestos insulation

Once a popular insulant, its use has been banned in most countries now. Asbestos releases minuscule fibers into the air, which irritate your lungs when you inhale them. What’s more, it’s been discovered that long-term exposure to it causes cancer.

Old buildings might still sport this type of pipe protection. If so, it is important that you remove it immediately. The airborne fibers can travel long distances, so standing in a room with this harmful mineral might threaten your health.