How to Install PVC Pipe

PVC pipe has made a tremendous improvement in plumbing. It replaces cast iron and galvanized pipe in almost all situations. Lightweight and easy to work with, PVC is available in many different sizes. Fittings and related materials are readily available at plumbing and hardware stores.

Step 1 - Understand PVC

PVC pipe is made from the plastic polyvinyl chloride. It's used in drains, as vents, and to handle waste in buildings. It is rigid, lightweight, and strong. Because of PVC pipe's ease of installation, it is ideal for drain applications under kitchen sinks and bathroom vanities.

The many fittings available for attaching PVC make it universal in all settings except very high temperature applications. It works much better for plumbing than the old standard cast iron pipe because it does not need to be hot soldered, is resistant to almost any alkaline or toxic substance, and is easy to install. There are two types, which are defined in standards—type 40 for personal homes, and type 80 for industrial settings.

Some Advantages

• Easy to install
• Chemically resistant
• Strong
• Fire-resistant
• High internal corrosion resistance
• Immune to galvanic or electrolytic attack
• Free from toxicity, odorless, and tasteless
• Low friction loss
• Low thermal conductivity
• Low installation cost
• Virtually maintenance free

Installation

Step 1 - Cut the Pipe

PVC can be cut easily. You can cut it with a hacksaw, but the abrasive disks that are made for miter saws work better to get a straight edge. A joint that is skewed due to the pipe not being cut straight can throw off the entire run of pipe.

Step 2 - Deburr and Fit

After cutting, clean all shavings out of the pipe and deburr (smooth) the inside edges. When the pipe is cut to the proper length, lay it out on the floor with the fittings in place to determine if the length is correct.

Step 3 - Clean and Cement

First, the pipe must be cleaned with all-purpose pipe cleaner, which is referred to as primer. Swab the primer around the end of the pipe and the inside of the fitting to ensure there are no contaminants that can get in the way of adhesion.

PVC is joined with a special type of cement. The cement sets up very quickly, so you must be ready to go as soon as it is applied. Coat the inner surface of the joint with the cement, insert the PVC pipe, and turn the pipe in the fitting a full turn if you can, and then turn it back to ensure that the glue has covered the entire joint. Be certain that the pipe is seated correctly in the joint for proper adhesion.

Step 4 - Install Pipe Hangers

Once the PVC pipe is in place, and you have determined it is the appropriate length, install pipe hangers to support the pipe. This eases the strain on the joints that could lead to possible leakage. Follow the recommendations for the distances from hanger to hanger. This is usually every four feet. You want to allow for movement and the expansion and contraction of the pipes during temperature changes. Be sure to protect the pipe from nails, screws, and other abrasive materials.

FAQ

What is the design life of PVC pipe?

Because of its composition, PVC will last for the design life of the home in which it is installed. Because it is rustproof and chemical resistant, a design life of 100 years is typical.

Is PVC pipe recyclable?

Yes. The pipe can be pulverized and returned to the extrusion process to manufacture new pipe. There are currently no standards for this. Because of its long life, PVC has not had a lot of exposure to recycling.

Is PVC resistant to UV rays?

Because of its inherent design, PVC pipe contains stabilizers that protect the pipe against the UV rays that are present in sunlight. Some discoloration may occur over time. After several years of exposure, you may see a slight reduction in the impact resistance of the material. By painting the exposed pipe with a latex paint (do not use oil-based) this problem will be virtually eliminated.

Is PVC pipe fireproof?

Like any plastic, PVC pipe will melt if subjected to high enough temperatures. However, it stops that process immediately when the fire source is removed. Studies show that PVC pipe in a typical installation accounts for less than one percent of all combustible materials in a building.

Mark Vander Sande, professional plumber, contributed to this article.