Installing Shut-Off Valves

Many times I've had to replace a sink or faucet only to find out that no shut-off valves were ever installed. In this case, you have to turn off the main water supply to the house to do the job. While you're at it, you might as well install those shut-off valves so that you don't have to do this in the future.

Tools

For this job, you'll need to have the following:

• Torch
• Solder and Flux
• Sandpaper
• Pipe cleaning brush(inside and out)
• Fittings
• Pipe Cutter

Shutting Off The Main Water Supply

The first thing you have to do is locate the main shut-off valve. This may be different for every house. If you have a basement, start there. If you have a well, turn the pump off. If you live in the city, you may have to locate the shut-off valve out near the street. It will take a special wrench (or a pair of channel-locks) to turn the valve. Once you feel you have the water turned off, go back to the faucet and open it up all the way. You might get a burst of water for a second as pressure is released.

Preparing the Pipes

Leave the faucet open. For copper pipes, use your pipe cutter to cut the pipe about 4 inches from where it comes up through the floor of the cabinet, or out of the wall. You'll want to measure these pipes, but typically they are ½". Most pipe cutters include a deburring tool which you should use to remove any sharp edges and metal fragments.
Make sure all water is removed from the pipe for several inches. If the pipes are vertical, this can be a challenge. For horizontal pipes, stuff some paper towel up in there to make sure it's dry. A bit of water will give you some serious problems when you try to solder.
Another thing that helps with vertical pipes is to open up faucets in other locations of the house to remove any pressure that still exists. This will help the water level drop. Stuff a paper towel down the pipe and try to dry it out. If there is a lot of water, use a straw to pull the water out. Insert the straw in the pipe and place your thumb over the end of the straw to seal it. Remove the straw and release your thumb (preferably over a bucket) and the water will drop out. Repeat this until you don't get any more water. Then dry the inside of the pipe with a twisted up paper towel.
Use fine grit sand paper to sand all around the end of the pipe. Sand down at least 2 inches from the end. The pipe should be shiny and smooth. You can also use a pipe cleaning brush, but typically there isn't enough room. You can also use this procedure to replace a corroded valve, like the one pictured here. This corrusion resulted from a leaky faucet.