What pipes should always be insulated?

Author: Wilton Cartwright  |  Last update: Wednesday, August 13, 2025

Hot Water Pipes By wrapping these pipes in fibreglass pipe insulation, you can keep that precious heat where it belongs - inside the pipe. Hot water pipes that run through unheated spaces such as garages or crawlspaces are particularly vulnerable to heat loss and should always be insulated.

What pipes need to be insulated?

Usually, only homes that are built-in cold climates where pipes are exposed to freezing temperatures take this extra measure. However, all the pipes in a home can benefit from being insulated, even if they only carry cold water.

Which pipes need to be lagged?

The most important lagging in unheated areas of your home is for the cold-water pipes which can normally be found in your garage or in your attic or loft. These are the areas where they are mora than likely to freeze up and potentially burst.

Should all hot water pipes be insulated?

All pipes connected to hot water storage vessels, including the open safety vent pipe and the primary flow and return to the heat exchanger, should be insulated for at least 1 m from their points of connection or to the point at which they become concealed”.

Should PEX pipe be insulated?

In colder climates, insulating PEX pipes can help prevent the water inside from freezing, which could lead to burst pipes. On the flip side, in hot and humid environments, uninsulated cold water lines may sweat, leading to potential issues like mold growth or water damage. Insulation can help mitigate these risks.

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Where should you not use PEX?

PEX pipe can be used as a service line based on its corrosion resistance to soil and water, its long life and its oxidative resistance. Our PEX pipe is not suitable for use in areas where the soil is or may become contaminated, including soil used for backfilling.

Is it code to insulate PEX?

PEX tubing does not provide any significant thermal insulation properties and would not meet code requirements without additional insulation.

Should all copper pipes be lagged?

Pipe lagging reduces the risk of pipe ruptures. Copper pipes, for example, can get extremely hot or cold, which can cause a pipe to burst especially in winter if freezing temperatures occur in unheated spaces. Acoustic Pipe Insulation is a soundproofing technique for pipes that helps to control and reduce noise.

Should PVC water pipes be insulated?

Even though plastic pipes can accommodate ice better than copper pipes, it is still important to insulate them to prevent water from freezing in the first place. Here is a more concise version of the text: Plastic pipes should be insulated like copper pipes to prevent freezing.

What pipe should not be used for hot water systems?

If the water temperature is over 140 degrees, PVC pipes and fittings start to degrade. This makes it less than a stellar choice for hot water heaters.

What plumbing pipe won't freeze?

PEX, or cross-linked polyethylene, has a chemical structure that gives it flexibility to withstand pressure increases and perform better in the winter. If water freezes in the pipe, for example, PEX will expand to accommodate the change. Then it will contract back to original dimensions once thawed.

Which pipes are most likely to freeze?

Pipes that freeze most frequently are: Pipes that are exposed to severe cold, like outdoor hose bibs, swimming pool supply lines, and water sprinkler lines.

What is the best pipe insulation for hot water?

Fiberglass insulation is a top choice for insulating pipes, particularly in high-temperature environments like hot water systems. Made from woven glass strands, it offers excellent thermal resistance, making it highly effective in preserving heat and minimizing energy loss in hot water pipes, especially copper ones.

What temp will insulated pipes freeze?

Insulated pipes may freeze in under six hours of 20 degrees weather, while it would likely take over 12 hours in 20 to 32 degrees weather.

Should copper pipes be insulated?

Many homes have uninsulated copper and Pex pipes that run through the basement ceiling joists. If the temperature drops below freezing the cold-water pipes can freeze. Water pipe insulation has an above-average resistance to thermal energy movement so insulating the pipes can help to prevent freezing.

Do I need to insulate a CPVC pipe?

All current model building energy codes require pipe insulation on service hot water and HVAC applications to prevent that loss.

Which water pipes need to be insulated?

To reduce water heating expenses, insulate hot water pipes wherever feasible. Cold water pipes warrant most insulation if the objective is to combat pipe condensation and the resulting mould.

Should plastic pipes be lagged?

Yes, lagging your pipes can improve water pressure by preventing heat loss and ensuring that hot water is delivered more efficiently.

Is PVC pipe winter proof?

However, both PVC and CPVC (think of them as coming from the same family of plastic pipes) are brittle and will crack at low temperatures. So, while not the worse solution, they are still vulnerable to freezing conditions.

Why are copper pipes not used anymore?

It has become expensive, can still corrode based on pH levels of water, and in cold climates, frozen water can cause copper pipes to burst. PEX installs quickly, which significantly reduces labor costs.

Do copper pipes freeze faster than PVC?

However, copper pipes are thin-walled and tend to lose heat rapidly, thus reaching the freezing point more quickly.

Can you get too much copper from copper pipes?

The risk is that we get too much. If too much copper is consumed (even relatively small amounts), this can lead to stomach and intestinal complaints such as nausea, vomiting and diarrhea. Over time, an excess intake of copper damages the liver, kidneys, and nervous system; it can even be fatal.

Where can PEX not be used?

PEX pipe is not approved for outdoor applications and is not approved for continuous UV exposure. PEX pipe should not be stored in direct sunlight.

Will PEX freeze if insulated?

Insulate your pipes: Insulating your PEX pipes can help to keep the water inside them from freezing. You can use foam insulation sleeves or tape to wrap around the pipes.

Should hot water heat pipes be insulated?

Insulating your hot water pipes reduces heat loss and can raise water temperature 2°F–4°F hotter than uninsulated pipes can deliver, allowing you to lower your water temperature setting. You also won't have to wait as long for hot water when you turn on a faucet or showerhead, which helps conserve water.

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