Types of Pipes for Water Systems

Throughout the centuries, people have used many piping types to deliver fresh water and carry away gray water and sewage. Some pipe materials were used for centuries, while others are modern marvels. Some proved to be problematic, and one material, lead, turned out to be a serious health hazard. Here is an overview of various plumbing pipe types in use today, including their benefits and drawbacks. 

Why It’s Important to Know the Types of Pipes

Just why is it important to know about the types of water pipes in your home? Different pipe materials vary widely in durability, with some being more prone to leaks or bursting than others (check out our article "Why Do Pipes Burst?" for more information). Your pipes significantly impact your water quality and determine the level of maintenance you need to devote to your plumbing. Some pipes are more susceptible to issues that can lead to banging and other water pipe noises. Some pipe materials have proven to be brittle or less reliable than first believed.

Common Pipe Materials Used in Water Systems

Copper 

Copper pipes are ideal for 1/2-inch and 1-inch water supply lines leading from the main water supply pipe to kitchen plumbing, sinks, and toilets. Plumbing contractors favor copper because it is clean, doesn't rust or corrode, and is very reliable. On the downside, copper pipes can freeze and burst if left exposed to the elements. Therefore, always ensure that pipes in unheated areas or those running through the outer wall of your home are properly insulated. 

Copper is one of the more expensive pipe materials and has become popular with thieves who steal it from homes and sell it to recycling facilities for cash.

Cross-Linked Polyethylene Pipes

Long used in Europe, PEX (cross-linked polyethylene) is a flexible, low-cost material seeing a resurgence in North American plumbing for water supply lines. At Roto-Rooter, we still prefer copper, but its rising cost is making the new PEX and PVC materials increasingly attractive. PEX comes in red for hot water lines and blue for cold water lines. It’s easy to work with, which helps keep labor costs lower. Additionally, PEX can expand if it freezes, and return to its original size after thawing. So far, its only downside is that rats and squirrels will eat it. 

Polyvinyl Chloride Pipes

Polyvinyl chloride (PVC) pipes are made from a plastic polymer and offer durability, affordability, and chemical resistance. PVC pipes can be either flexible or rigid, making the material suitable for a wide range of applications. PVC is rarely used for water supply pipes these days, but it is well-suited for underground and interior sewer and drain lines; however, direct sunlight can cause the material to become brittle. 

Chlorinated Polyvinyl Chloride Pipes

Chlorinated polyvinyl chloride (CPVC) can withstand higher temperatures than regular PVC and is often used for hot water supply lines. CPVC has a greater tensile strength than PVC but is less flexible. However, CPVC installed in the past 15+ years is now turning brittle and beginning to fail much earlier than expected. 

Galvanized Steel

Galvanized steel pipes were used for decades but have fallen out of favor in new construction. After years of use, minerals in water react with the galvanizing material (including zinc and lead) to cause scale buildup inside the pipe. The scale gradually narrows the interior pipe diameter, resulting in lower water pressure, reduced volume, and the potential for lead to leach into drinking water. 

Cast Iron

Cast iron pipes are not a new development in modern plumbing, but they were common in homes built before the 1970s. Cast iron corrodes from the inside out, so damage may go unnoticed until the pipe cracks, leaks, or bursts. Cast iron pipes have a lifespan of 50-100 years, but they typically begin to deteriorate after approximately 25 years. If your home uses cast iron plumbing pipes, have them assessed and consider replacing them with modern pipe materials. 

High-Density Polybutylene Pipes 

High-density polybutylene (HDPE) pipes are flexible plastic pipes that are durable, lightweight, and resistant to corrosion. Plumbers can join HDPE pipes using heat fusion for strong and leak-proof connections. HDPE has lower high-temperature resistance than PVC and can soften when exposed to temperatures above 140°F.

ABS Pipes

ABS, or acrylonitrile butadiene styrene, is a plastic pipe material sometimes used for drain, waste, and vent piping. ABS has high impact resistance, resists high temperatures, and is recognizable by its distinctive black color. It is a rigid pipe, and there are no exible varieties.

Clay

Clay has been used to make pipes as far back as 4,000 BC, and the material was a popular choice for sewer lines into the 20th century. Clay pipes can be problematic, however, and they are porous, brittle, heavy, and because the joints do not seal well, they are vulnerable to tree root infiltration. 

Types of Water Pipes Explained

Home plumbing systems consist of three main components: the water supply line, the hot and cold water lines, and the drainage system.

• The main water supply line connects a municipal or private water source to your water meter and home plumbing. 
• Hot and cold lines direct water to your home’s faucets and spigots. 
• Drainage lines carry wastewater and sewage away from the home. 

What Type of Pipe Is Used for Main Water Lines?

Copper, PEX, and sometimes PVC are used for main supply lines. Which one you use depends on multiple factors, including local water pressure, climate, soil type, and local plumbing codes. 

What Type of Pipe Is Used for Underground Water Lines?

Underground water line pipe materials include PEX, PVC, or HDPE.

• PEX can expand and contract with temperature changes, but must still be buried below the frost line. 
• PVC has a long lifespan and is resistant to corrosion. Some plumbing codes restrict the use of PVC for potable water out of concern chemicals from the pipe could leach into the water. 
• HDPE is flexible, allowing for easier installation, and it withstands a wide range of temperatures. HDPE is a popular choice for trenchless pipe bursting methods, which minimize landscaping disruption. 

Signs You May Need to Replace Your Pipes

Many plumbing problems can stem from older pipes. Signs you need to replace your pipes include: 

• Frequent leaks
• Rusty, discolored water
• Low water pressure
• Banging, whistling, or gurgling pipes
• High water bills
• Visible corrosion
• Consistently slow drains
• Unpleasant water smell or taste
• Unexplained wet spots or green spots in the yard

If you notice any of these signs, contact Roto-Rooter so we can assess the health of your pipes. We’ll help you determine if it's time to replace your pipes and offer advice on the best pipe materials for the job. As always, Roto-Rooter tries to give you as many viable options as possible so you can decide which one fits your needs and budget.