PVC plastic is an affordable choice for home plumbing. It doesn’t corrode, is flexible and easy to install, and can be used with many different connections. But PVC can’t handle extreme heat, it melts and could potentially cause negative health impacts. Because of this, using PVC pipes for your drinking water supply is not advised.
What is PVC plastic?
Polyvinyl chloride (PVC) was one of the first synthetic plastics that was discovered, synthesized by a German chemist in 1872. It’s made from salt and oil or gas and is the world’s third-most widely produced plastic polymer.
PVC is made into rigid and flexible plastic products. Rigid PVC plastic can be used for such items as signage, flooring, window frames, and pipes. Flexible PVC is used for making products like plastic bank cards, food containers, water bottles, footwear, and inflatable pools, among many other uses. It can even be blended with cotton or linen to make canvases for painting.
Using PVC plastic for plumbing and pipes
This synthetic plastic is affordable and doesn’t rust or corrode over time, which is why it is such a popular choice for indoor plumbing. PVC plastic is easy to work with, requiring no welding or metalwork, and is versatile. It can be used with many different fittings and sizes.
Typically, PVC pipes are used for sink, toilet, and bathtub drain lines, as well as for main water supply lines, irrigation piping, and vent stacks. PVC was one of the first types of plastic pipes that were used to replace old copper pipes.
Usually, PVC pipes are coloured white but also come in different colours and thicknesses and with different marks on the pipe, for specified uses. A primer is used to soften the PVC for making connections, then applying PVC glue to melt the joints and pipe together.
Limitations of PVC pipes
While it is a great option for most warm and cold water plumbing, PVC pipes can’t be used for your hot water supply. PVC will start to warp under extreme heating conditions and will degrade under UV light for an extended period of time, such as outside in the summer.
PVC plastic has many uses but it can also be dangerous. It’s made of vinyl chloride and organotin compounds which can cause negative health reactions and are carcinogenic. Chemicals usually stay locked inside the pipe material but can leach into your water supply. In fact, drinking water from a PVC pipe may have a plastic taste to it. This is why we discourage PVC plastic pipes from being used for drinking water.
Safer options for your home’s drinking water supply
Thankfully, there are many other material choices for your home’s plumbing system pipes. Galvanized steel, copper, CPVC, and PEX are all typically used for pipes. Each material has different strengths and weaknesses, in terms of how they handle extreme temperatures, how long they last, how easy they are to install and repair, and how long the pipes will last.
Galvanized steel pipes: If you have an older home, your water pipes may be made of galvanized steel. These pipes are made of steel, yet treated with a zinc coating to prevent corrosion, and can handle hot water.
Cutting, threading, and installing galvanized steel pipes can be expensive and time-consuming, so updated plumbing systems generally use other materials. For older homes, galvanized pipes should last from 30 to 50 years.
Copper pipes: When galvanized steel pipes became less popular, copper pipes were often used instead. While not an affordable option, copper pipes are great for both hot and cold water distribution. However, with age and use, copper pipes begin to thin and leak, though they should last for up to 50 years.
Copper is resistant to corrosion and doesn’t degrade with water, which makes it safe for pipes used for drinking water. Care should also be taken when installing copper pipes in a place with acidic water. As even slightly acidic water, with a pH of 6.5 or less, can cause copper particles to leach out of your pipes and into your water supply.
As copper is one of the most expensive materials used, there is a high risk of theft in vacant houses.
CPVC pipes: For a plastic pipe that can withstand high temperatures, CPVC is a great option. CPVC, which stands for chlorinated polyvinyl chloride, is more flexible and can handle much higher temperatures than PVC. CPVC pipes can handle water heated up to 82 degrees Celsius, so warping isn’t an issue.
CPVC is a thermoplastic made from PVC resin and is safe for use with drinking water. It’s easy to work with, such as with welding, forming, and machining, and is a strong material. Typically it’s made in a cream-coloured or off-white coloured pipe. CPVC pipes have the same diameter as copper and PEX pipes so the same fittings can be used. They’re also very long-lasting, generally able to work for 50 to 80 years.
PEX pipes: Pipes made from PEX (cross-linked polyethylene) are more durable than copper and can handle both hot and cold water temperatures. PEX is much more resistant to acidic water than copper. These pipes, also called XLPEI pipes, are an affordable option and often last for more than 50 years.
PEX can handle water heated up to 120 degrees Celsius without melting or warping. It’s easy to use and install, as it’s flexible and doesn’t need many joints, and it’s easy to transport.
Protecting your drinking water source
With all these options and their different costs and benefits, you may feel uneasy about choosing new pipes for your home. Plumbing and Heating Paramedics is here to help with choosing, installing, and repairing your home’s water pipes. Our specialists will walk you through various options and costs, as well as potential solutions.
Do you have any questions about the choices for water pipes for your home? Have you had new pipes installed? We welcome your questions, comments, and suggestions below.