How to Measure Water Pipes

When replacing water pipes at home, you'll have to measure to determine the length of pipe you need to cut. The length can differ, however, based on the type of pipe you're using. This article will cover measurements for rigid plastic pipe, copper pipe, and galvanized pipe. It assumes you're connecting plastic to plastic, copper to copper, and galvanized to galvanized.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Yardstick or carpenter's folding rule

Copper Pipe

1. Use a measuring stick or carpenter's folding rule.

2. Measure the length of the pipe from the face, or end, of each fitting or joint you need to connect.

3. Insert your measuring device inside the fitting to find the length from the face of the fitting to the shoulder – the place where the pipe butts against the inside of the fitting.

4. Add the two measurements from inside the fittings, and add the length of the pipe from Step 2 for the total length.

Rigid Plastic Pipe

5. Determine the length of the pipe from face to face of the fittings it will connect. Use a yardstick or other rigid measuring device.

6. Measure from the face (end) of each joint to the shoulder, the place the pipe will fit snugly against.

7. Add the length of the water pipe from Step 2 to the measurements from the two fittings for the total length.

Galvanized Pipe

8. Find the length of the pipe from fitting to fitting. Use a yardstick or carpenter's folding rule.

9. Determine the inside diameter of the water pipe. This will be the length of pipe that threads into the fitting. For example, if the pipe is 1/2 inch in diameter, it will thread into the fitting 1/2 inch. If it is 1 inch in diameter, it will thread in 1 inch.

10. Add the thread-in lengths from the two fittings to the measurement from Step 1 to find the total length. So if the thread-in length is 1 inch for each fitting, you would add 2 inches to the length from Step 1.

Tips & Warnings

• Avoid using a tape measure. The tape can sag in the middle if you're measuring a long pipe, giving you an inaccurate measurement when it's time to cut the pipe.

Resources

• Find pipes for your plumbing needs at Menards.

[Tom3]

on 12/6/2008 The instructions for galvanized pipe measuring pose a question - when measuring for 2' galvanized pipe engagement with fittings do you allow for a 2" engagement?