Are you planning to install a new bathroom sink or replace an old one?
One crucial step in the process is connecting the P-trap. This may seem like a daunting task, but with the right tools and instructions, it can be done easily.
In this article, we will guide you through the process of connecting a P-trap for your bathroom sink. From gluing the trap adapter onto the pipe in the wall to tightening the slip joint nuts, we’ll cover everything you need to know to ensure a leak-free connection.
So, let’s get started!
How To Connect P-trap For Bathroom Sink
First, for a new sink installation, you’ll typically have a piece of pipe sticking out of the wall. To connect the P-trap, you’ll need a trap adapter that needs to be glued onto the pipe in the wall. If your pipes are ABS, use ABS cement. Swab the inside of the trap adapter with some cement and do the same for the outside of the drain, making sure to fully coat both surfaces. Then push on the adapter all the way in, giving it a slight twisting motion, roughly a quarter turn.
Next, let’s take a look at the P-trap kit. All of these parts typically come in the kit: the waste drain, two plastic or rubber washers, and two slip joint nuts.
To connect the two pipes, slip a nut onto the waste drain and slip it into the other pipe, then hand tighten the nut. No washers are required here.
The idea is to slip the waste drain onto the sink drain, but as you can see, both drains aren’t the same size. That’s why the kit comes with two different-sized washers. You’ll note one of them is much too loose, but the other one fits just right. It’s also important to note the orientation of the washer when using slip joints: make sure the tapered side is facing whatever you’re trying to connect to.
With that in mind, slip on a nut followed by the washer. Now you can put on the P-trap but if your waste drain is too long for your setup, you’ll need to cut it using a hacksaw to cut the pipe to the right length.
With the pipe cut to size, attach the waste drain to the trap adapter. But first, slip on a few parts starting with a slip joint nut facing towards you, then another nut facing the wall and lastly, the remaining washer tapered side towards the wall.
If your P-trap adapter came with its own slip joint nut that eliminates the need for a washer, replace the parts that came with your P-trap kit with this one.
Now you can go ahead and slip that in and loosely tighten it so it can be repositioned later if needed. Position your trap and connect the slip joint nuts on each end, again loosely tightening and adjusting as needed to make sure everything lines up without stressing any of the joints.
If your parts don’t line up and you find yourself forcing a connection, you’ll likely end up with a leak. Once everything is aligned, hand tighten all of the nuts. After that, use some slip joint pliers to tighten them up a little more so that they are nice and snug, making sure not to overtighten.
Gather Your Tools And Materials
Before starting the process of connecting a P-trap for a bathroom sink, you’ll need to gather a few tools and materials. Here’s what you’ll need:
– Trap adapter: This is a small piece that connects the P-trap to the pipe in the wall. Make sure to get the right size and type for your pipes (e.g. ABS or PVC).
– P-trap kit: This includes the waste drain, two plastic or rubber washers, and two slip joint nuts.
– Hacksaw: You may need to cut the waste drain to the right length for your setup.
– Slip joint pliers: These will be used to tighten the nuts on the P-trap and waste drain.
– ABS cement (if using ABS pipes): This will be used to glue the trap adapter onto the pipe in the wall.
Make sure to have all of these tools and materials on hand before starting the installation process.
Remove The Old P-Trap (If Necessary)
Before connecting a new P-trap, you may need to remove the old one. To do this, start by placing a bucket under the trap to catch any spills. Then, depending on the type of trap you have, you’ll need to use slip-joint pliers or a wrench to loosen the nuts that hold the trap in place.
For a plastic P-trap, you can simply unscrew the nuts by hand, gripping the trap firmly and rotating each nut counterclockwise. You’ll need to unscrew two nuts: one that holds the trap to the tailpiece and another that holds it to the drain line.
If you have a metal P-trap with slip joint nuts, start by loosening these nuts on either side of the sink trap using a wrench or channel locks. Once they’re loose, you can finish unscrewing the trap by hand.
Once you’ve removed the old P-trap, be sure to keep all of the parts aside for disposal. With the old trap out of the way, you can now proceed with connecting your new P-trap as outlined in the previous section.
Prepare The Pipes
Before connecting the P-trap, it’s important to prepare the pipes. For a new sink installation, you’ll typically have a piece of pipe sticking out of the wall. To connect the P-trap, you’ll need to glue a trap adapter onto the pipe in the wall. If your pipes are ABS, use ABS cement.
Begin by cleaning the end of the pipe with a clean cloth to remove any dirt or debris. Then, apply a small amount of ABS cement to the inside of the trap adapter and to the outside of the pipe. Be sure to fully coat both surfaces.
Next, push the trap adapter onto the pipe all the way in, giving it a slight twisting motion, roughly a quarter turn. Hold it in place for a few seconds to allow the cement to set.
Before attaching the P-trap, make sure that all of your pipes are cut to the correct length and that all necessary fittings are in place. This will ensure that your P-trap fits properly and does not leak.
By following these steps and properly preparing your pipes, you can ensure a secure and leak-free connection for your P-trap installation.
Connect The P-Trap To The Sink Drain
Now that you have the trap and waste drain connected, it’s time to connect the P-trap to the sink drain. Slip on a nut followed by the washer, making sure the tapered side is facing towards the sink drain.
Position the P-trap and connect the slip joint nut to the sink’s tailpiece. Loosely tighten and adjust as needed to ensure everything lines up without stressing any of the joints.
Again, if your parts don’t line up and you find yourself forcing a connection, you’ll likely end up with a leak. So take your time to make sure everything is aligned properly.
Once everything is aligned, hand tighten all of the nuts. After that, use some slip joint pliers to tighten them up a little more so that they are nice and snug, making sure not to overtighten.
And that’s it! You have successfully connected your P-trap for your bathroom sink. Remember to always follow proper plumbing procedures and safety protocols when working with plumbing systems.
Tighten The Slip Joint Nuts
If you notice a leak at one of the joints between pipes, the first thing to try is tightening the slip joint nuts. For metal traps, tighten them hand tight plus about a half turn using slip-joint pliers to grip the nut. For plastic traps, just hand tighten and give the nut about a quarter of a turn with slip-joint pliers if needed.
If tightening the connection doesn’t seem to fix the leak after running water through it again, the next step is to disassemble the trap. First, put a bucket underneath the trap and use pliers to disconnect the slip joint nuts from the tailpiece and drainpipe. Then, water will pour out where you disconnected the pipe. This will allow you to clean the pipe out with a clothes hanger to see what might be trapped inside. If you see any faulty parts, be sure to replace them and then reconnect the pipes back together using pliers.
Lastly, run water again, look for leaks and tighten any areas that need tightening. Put newspaper under the pipe and check for leaks the next day. If this doesn’t work, removing the entire trap comes next. Remember not to overtighten any of the nuts as this can cause damage to the pipes or trap and lead to further leaks.