If the connections between your sewer pipe and the U-shape pipe are loose and can’t be fixed by tightening the connecting nuts, you’ll have to install a new p-trap assembly. (i.e. P-trap replacement.) Corrosion and loose joints are the common issues with p-trap and, if they persist, you need to replace the drain trap ASAP to avoid water damage.
Wondering how to replace a drain trap? Don’t fret; you’re at the right place. This article will guide you to know how to connect p-trap to wall drain step-by-step. You only need to know the P-trap anatomy and how it works, and you’re set to go.
The Anatomy of the Drain Trap
A drain trap consists of a waste arm and a trap bend.
- The waste arm is a straight pipe length with one end fitting into the opening of the branch drain in the wall. The other end is curved down to attach to the trap bend.
- The trap bend is U-shaped. One end is attached to the vertical tailpiece, which drops from the sink drain, while the other is connected to the waste arm. The trap end design makes it easily removable to ease the clearing of clogs.
How a P-Trap Works?
A drain trap is also known as a P-trap. The name P-trap is derived from its appearance- a looping shape that looks like the letter “P“. Every time you use the sink, a small amount of standing water remains trapped at the end of the trap. The water seals the drain’s opening and prevents sewer gases from seeping through the sewer pipes from the sewer system to your house. Also, look at the P-trap installation diagram below to understand how it works.
Also, the drain trap acts as a recovery point for small valuables like rings or necklaces when they go down the drain through the sink. Instead of those objects getting washed away into the main drain, they remain in the Ps-trap. It’s also through the trap where you can quickly clear clogs in the branch drain attached to the wall or from the trap bend.
What Causes P-Trap Replacement?
Some reasons which can force you to replace your drain trap include;
01. Pipe Leaks
In most cases, pipes of P-trap are assembled with PVC, Metal, or ABS. These pipes are vulnerable to corrosion, leaks, and damage as they become older. The first issue you’re likely to identify is leakage between the pipe connections and if you don’t act fast, the issue can lead to damage to your kitchen cabinets.
When a P-trap starts leaking under the sink, it causes the elimination of the water seal in the pipe, causing the methane gases and nitrogen hydrogen sulphide to leak into your house. This results in a bad smell in your home.
To avoid this, you need to replace the P-trap at the earliest. The new P-trap would block the toxic sewer gases from seeping into the household.
Before You Begin P-Trap Replacement
Set a few paper towels or rags and a medium-sized bucket under the trap to prevent the water from damaging your cabinets. Also, ensure that the kits you bought match the existing P-trap in terms of pipe configuration and diameter.
If possible, avoid the drain trap kits that use flexible tubing. They are prone to clogging as they’re susceptible to catching debris. Instead, go for the smooth-walled pipes as they would make your drain trap more trouble-free.
Understand one thing, replacing a drain trap is not rocket science. You only need the right tools and equipment, and you’re ready to go.
What You’ll Need For P-Trap Replacement In House?
The following tools/equipment required for replacing p-trap under sink –
- P-trap replacement kit
- Work light
- Pipe cutter or hacksaw
- Tongue and groove pliers
How To Replace P-Trap Under Kitchen Sink?
Follow the below step-by-step Instructions For P-Trap Replacement.
Step 1: Remove the Old Drain Trap
- Place a bucket under the existing drain trap to catch any water.
- Then, using tongue and groove pliers, loosen the slip nuts integrated to the curved drain trap bend to the trap arm and the sink tailpiece.
- To loosen the trap bend, wiggle it slightly as you slide it off the pipe and then empty it into the bucket.
- Loosen the slip nut attaching the waste arm to the opening of the branch drain, and then slide out the waste arm from the opening as you wiggle it.
- Now, set aside the slip nuts, washes, and old drain parts. Look at the P-trap assembly diagram below and understand how to quickly remove the old drain trap.
Step 2: Connect the New Waste Arm
- Slide two slip nuts onto the waste arm’s end, one nut near the arm’s straight end and the other at the curved end.
- Slide a slip washer onto the waste arm’s straight end with the bevel facing out.
- Into the opening of the branch, drain slides the straight end to test-fit the waste arm.
- Thread the slip nut loosely onto the threaded fitting- on the opening of the branch drain. Don’t tighten the nut fully, as you might need to make some adjustments.
Step 3: Attach the Trap Bend
- First, check the size of the waste arm. If it’s too long for the sink’s configuration, use a PVC pipe cutter or a hacksaw to cut it down the straight end to size.
- Then onto the sink drain’s vertical tailpiece, slide a slip nut followed by a slip washer with the slip washer’s bevelled side facing downward.
- Onto the sink tailpiece, slide the trap bend, and position it in such a way that the opposite side accepts the waste arm’s curved end.
- Now, tighten the waste arm slip nut and the tailpiece nut lightly onto the threaded fitting of the trap bend. The nuts would compress the slip washers to tighten the threads to make a tight seal.
Step 4: Tighten the Fittings
- After ensuring that all the trap fittings correctly fit together, use the pliers to tighten all the nuts. Be cautious not to over tighten them. Just ¼ turn after hand-tightening would suffice.
Step 5: Test the Fittings
Now check for leaks in all the fittings by running water through the drain as you check for leaks in the slip nut connections. If there is any leakage, tighten the nuts gently using pliers. Avoid over tightening the nuts, more so if they are made of plastics.
How Much Does It Cost To Replace a P-Trap?
It is difficult to speak about the exact p trap replacement cost. The price will differ depending on where you are living. For example, installation costs will be higher in urban areas, it will be lesser in the rural areas. It also depends on the p-trap kit. (I.e. which type of trap you are going to use – Steel or PVC)
In the end, you now have a thorough understanding on how to replace p trap. Can you see how simple it is to fix your P-trap? Now, roll your sleeves and get the work done. In case of any questions, feel free to ask in the comment box below. Good luck, buddy!
If your sink trap is leaking, you should fix it as soon as possible to avoid further damage. Refer to the following blog to learn how to repair a leaky sink trap properly –
Jennifer Kiminza – Jennifer Kiminza is a content writer and content marketing professional at Hub Spot, an inbound marketing and sales platform that helps companies attract visitors, convert leads, and close customers. Previously, Jennifer worked as a marketing manager for a tech software startup. She graduated with honors from Nairobi University with a dual degree in Business Administration and Creative Writing.