Replacing Drain Traps

P-traps - those curved pieces of drain pipe underneath your sink - do a lot of dirty work. Occasionally, they leak, become corroded or get plugged with years of accumulated soap and grease. When that happens, replace an old trap with nice new ones. Traps are made from ABS (black), PVC (white), or brass (either chrome plated or natural colored.) Replace your drain trap with the same type of trap you remove. Traps come in 1 1/4 inch (standard bathroom sink) or 1 1/2 inch (standard kitchen sink) inside diameter sizes. Be sure to check so you get the right size replacement at your local store.




Step 1

Step 1: Remove the old drain trap assembly

Before removing the drain place a small container or plastic bag under the sink to catch any water and debris.


Start removing the old drain assembly from the top down. Use the pliers to unscrew any stubborn slip nuts. Remember the drain trap (the U shaped bend) will have a small amount of standing water so have your bucket or bag handy. To make sizing the new drain pieces easier keep the old drain parts for now.


Step 2

Step 2: Place a tailpiece washer into the flared end of the tailpiece

To replace a kitchen drain sart with a flanged tailpiece. Put the tailpiece washer into the flared end of the tailpiece, then attach the tailpiece by screwing the slip nut onto the sink strainer. For a bathroom drain the tailpiece is attached differently. In a bathroom the sink drain starts as a tailpiece and may reach the P-trap without additional parts. If not add a tailpiece to make up the distance cutting it to the needed length.


Step 3

Step 3: Attach the fitting with slip washers and nuts

If you're working on a sink with two basins, use a continuous waste-T-fitting to join the tailpieces. Attach the fitting with slip washers and nuts. Make sure the beveled sides of washers face the threaded portion of the pipes. Putting a little pipe lubricant on the slip washer will ease installation and ensure a tight fit.


Step 4

Step 4: Using a slip nut and washer, attach the trap arm to the drain stub-out Attach the trap arm to the drain stub-out, using a slip nut and washer. Remember to keep the beveled side of the washer facing the threaded drain stub-out. If necessary, the trap arm can be cut to fit with a hacksaw.

Step 5

Step 5: Attach the trap bend to the trap arm Attach the trap bend to the trap arm, using slip nuts and washers. The beveled side of the washers should face the trap bend. Tighten all the nuts with a pair of slip joint pliers. Never use teflon tape on white plastic pipe threads and fittings. Be careful not to over tighten and crack the slip nuts.