Keep your pipes freeze-free and flowing this winter
The best pipe insulation material depends on a few factors—mainly temperature, location, the type of pipe, and what you hope to achieve with insulation. Do you want a more energy-efficient home or are you looking for the best pipe insulation to prevent freezing? In general, pipe insulation materials such as fiberglass or mineral wool are best for pipes exposed to hot temperatures, while foam and rubber are a better fit for cold water pipelines but work in hot pipes as well.
To help you decide what type of pipe insulation is best, we will review the five most popular pipe insulation materials, each type’s use, and where they work best so you can pick the one(s) that best fit your unique needs and budget.
Fiberglass pipe insulation works well with both cold and hot water pipes. However, it’s best to use these on copper pipes that transport hot water since they preserve the temperature better than other materials. One thing to keep in mind is that these are more expensive than most other options. The typical price per linear foot is around $1.50 for 3—to 6-foot tubular pieces.
Best For: This type of insulation is best for DIYers on a budget, particularly those insulating cold water pipes. It’s one of the most inexpensive types of pipe insulation and relatively easy to work with—whether you’re winterizing an outdoor faucet or insulating condensation-prone indoor pipes. You won’t even need to wear personal protective equipment to safely install it.
Cost: $0.20 to $1.35 per linear foot
Works best on cold water pipes
Flexible material
Inexpensive
Mold resistant
Not as preferable for hot pipes
Fiberglass pipe insulation materials work well with both cold and hot water pipes. However, it’s best to use these on copper pipes that transport hot water since they preserve the temperature better than other materials. One thing to keep in mind is that these are more expensive than most other options. The typical price per linear foot is around $1.50 for 3- to 6-foot tubular pieces.
Best For: Fiberglass insulation holds up best to heat, so it’s the go-to choice for homeowners insulating water pipes with extremely hot water. It’s also a great option to insulate pipes in areas with a fire risk or places exposed to high summer temperatures (like an unfinished attic in a warm climate).
Cost: $0.30 to $1.50 per linear foot
Can be used on both cold and hot conducting pipes
Performs best on hot pipes
Easy to install
Comes in tubes and wraps
More expensive than others
It is not as flexible as rubber and foam
Requires careful installation because it’s an irritant
As with foam and fiberglass, rubber is also a versatile material for both cold and hot pipes. You can use it with copper pipes, PVC, and iron pipes. Price-wise, the average cost ranges somewhere in between foam and fiberglass at around $1 per linear foot.
Best For: Because it’s so flexible, rubber installation is a good choice for difficult-to-reach or challenging areas. Rubber tubular insulation is so flexible that you don’t need a tee or elbow joint but can strategically cut a tubular section.
Cost: $0.90 to $1.45 per linear foot
Versatile and flexible
Compatible with copper, PVC, and iron pipes
Can be used on AC and plumbing pipes
A good choice for hot and cold pipes
Mold- and condensation-resistant
Fire-rated
Slightly expensive
Mineral wool, also known as rock wool, is made from pieces of natural rock that are heated and spun into a thread (or wool-like) texture. Similar to fiberglass, this type of pipe insulation works on both hot and cold pipes. It’s particularly adept at withstanding extreme heat—more than 650 degrees F, depending on the brand—and it’s fire resistant.
Mineral wool is a relatively sustainable option since most of it is either recycled or recyclable, but it comes with potential health risks and can be dangerous to inhale. According to the Environmental Protection Agency (EPA), certain fine mineral fibers are possible carcinogens, though rock wool and slag wool are not classifiable.
Best For: Mineral wool is best for noise reduction and efficiency—especially around older (read: louder) HVAC systems or hot water pipes. Since it’s normally made from volcanic rock, which naturally has low thermal conductivity and fire resistance, it’s particularly good at controlling heat loss. This leads to less energy usage and lower energy bills.
Cost: $1.40 to $2.10 per square foot
Extremely fire resistant
Reduces noise
Repels moisture
Sustainable and recyclable
More expensive than rubber or foam insulation
Possible carcinogen
Spray foam insulation is what it sounds like—an expandable type of foam that you can spray onto pipes. The expandable spray application makes it ideal for tight or awkwardly shaped spaces. Because of its flexibility, it’s suitable for pipes (like copper) that expand with heat. It can damage certain plastics, so use caution before applying it to PVC or CPVC (chlorinated polyvinyl chloride) pipes.
Spray foam insulation is either open-cell (which has a lower R-value and lower cost) or closed-cell (which has a higher R-value and higher cost). Polyurethane foam spray is the most common spray foam material, but according to the EPA, it can potentially off-gas volatile organic chemicals (VOCs). You can find water-based alternatives or foam sprays made from vegetable oil.
Best For: Spray foam is best used in tight or awkwardly-shaped spaces where it would be difficult to install other types of installation. If you’re dealing with condensation, it’s best to choose a high-density, closed-cell foam that is water-resistant.
Cost: $1.25 to $1.50 per square foot
Can be applied in hard-to-reach or awkwardly-shaped spaces
Reduces noise
Long-lasting
Energy efficient
Polyurethane foam spray can off-gas VOCs
Some types can damage plastic piping
Open-cell foam is not water-resistant
There are a few things to consider when planning to insulate your pipes, such as their location, type, and why you want to insulate them. Most homeowners use insulation as a way to keep pipes from freezing or increase their home’s energy efficiency, but you might also want to insulate particularly noisy pipes or cold pipes that are prone to condensation.
Insulation is rated with what’s called an R-value. The higher the R-value, the more powerful the insulation. This is sometimes a delicate balance because you may need a lightweight or flexible type of insulation—especially around pipes that expand and contract as temperatures change. If you’re not sure which type of insulation works best, call a plumber near you. They won’t just point you in the right direction; they’ll be able to safely and effectively install your installation.
Your pipes’ location determines if you need to insulate them or not. If they’re outdoors or indoors in a non-heated room, like an unfinished basement or a crawl space, you’ll need to insulate them to prevent freezing. At what temperatures do pipes freeze? It’s a risk anytime the temperature drops below 32 degrees Fahrenheit. In this case, always choose pipe insulation with the highest R-value.
There are different types of pipes used in most homes, including copper, PVC, and PEX pipes, to name a few. These pipes have different attributes. For example, PEX pipe freezing tends to be less common than copper. Though insulation materials can be very versatile, some types of insulation work better than others, depending on the pipe's material.
This is one of the most important factors when choosing insulation. The best pipe insulation to prevent freezing is sometimes different than the best pipe insulation to prevent condensation. Temperature maintenance is essential. Another reason to insulate pipes is to reduce condensation and sweating. For example, an insulated hot water pipe runs more efficiently since it preserves hot water better than one exposed to airflow and the elements.
You can buy pipe insulation materials in your local hardware store or in major home improvement stores. You can also shop for insulation online, where you may be able to more easily buy in bulk. When shopping, make sure you know your pipe's dimensions so you can buy the correct size of pipe insulation materials for your pipes.
The benefits of insulating your pipes include preventing freezing, sweating, and condensation. In addition, insulating your pipes can make your home more energy-efficient by keeping your pipes from losing or gaining heat. You’ll be able to turn the temperature of your water heater down by two to four degrees Fahrenheit. According to the U.S. Department of Energy, this can reduce energy costs by 3% to 4% per year.
Yes, insulating your pipes is a doable DIY project. These materials are generally easy to install since they’re pre-fabricated to fit specific pipe dimensions. You can complete the project in as little as one weekend day. Of course, if you’re short on time, you can always hire a local plumber to help with this task.
The R-value is a rating that measures the insulation’s thermal resistance (in other words, how well it insulates). For most pipe insulation, the R-value will fall between one and five. The higher the R-value, the more protection for your pipes. All pipe insulation materials should have an R-value listed in the product description or on the product label.
Unfortunately, pipes can freeze when exposed to prolonged freezing temperatures, whether or not you have installed insulation covers. Insulation covers, however, are still an excellent idea as they can reduce the chance of your pipe freezing by keeping the pipes closer to the temperature of the water inside the pipe.
