Sign up or log in to customize your list. Here's how it works: Anybody can ask a question The best answers are voted up and rise to the top After installing a new bathroom sink, the drain tailpiece doesn't line up with the trap coming out of the wall. I've seen flexible accordion hoses for this, but I think that violates code (P3002.3.1). I live in California. My tailpiece is 1.25" (OD) without threads. The trap is 1.5" (ID) with male threads. What's the best way to do this? By the way, I have a flexible accordion piece from the old sink, which fits on the trap, but it has male threads on top, so it connect to the tailpiece. So I don't understand how those flexible pieces are supposed to work anyway. plumbing bathroom sink drain drain-waste-vent I had the exact same problem under my bathroom sink. Here's a picture of how I resolved it. The first elbow off the sink is 1.5" because I couldn't find a 1.25" female-to-female elbow in my local Home Depot.
I used a 1.25" sized compression washer in the larger elbow to get the smaller 1.25" elbow to fit snugly. You should be able to do the same kind of thing by using the more-available 1.5" pieces whenever you have to and mating them with the smaller 1.25" pieces you may have to use with 1.25"-sized compression washer. If the p-trap will not swing enough to align with the tail piece, you will need to provide an offset on the vertical. I would do this by changing the p-trap to a hub connection type (should be able to reuse the existing union 90) and then hard pipe up from the p-trap, installing two 45 elbows on the vertical and then connecting to the tail piece with a hub x slip joint adapter. The photos posted above were really helpful, since many people may not know what connectors and adapters are available -- as I didn't before replacing two vanities. Therefore, I thought I'd post photos of what I did and the components I used. The first thing to do is come out of the wall with a wall tube (otherwise known as a quarter-bend wall tube).
Cut the long side if necessary, so it slides into the drain tube in the wall (make sure you have at least several inches in the wall drain). The flange typically connects to the short leg of the J-trap. There are two types of J-traps: one with a threaded slip-joint fitting on each end and a "repair" J-trap, with a slip-joint on the longer leg and a compression flange on the other. Use whichever one is suitable for your existing piping. The connectors you use depend on two factors: how far is the tailpiece horizontally from the drain connection, and how far above or below it? In the above situation, the drain connection is several inches to the side of the tailpiece and slightly below it. To close up horizontal distance, you can use another wall tube cut to the appropriate length, connected to the J-trap. The other end connects to a 90-degree elbow to make the turn and cover the vertical distance. Use a reducing washer to adapt a 1 1/4" tailpiece to 1 1/2" drain piping.
(All the components pictured here are from Home Depot; other stores have similar items). My other vanity has greater horizontal distance and less vertical. Therefore, I connected the longer leg of the J-trap to the wall tube, to get more displacement down, so the connectors would have room to cover the horizontal distance on the way back up. In this case, the 90-degree elbow didn't quite make it to the bottom of the tailpiece, so I had to add a coupling, attached to the elbow with a scrap piece of the wall tube I had cut off. If, for some reason, you need even more vertical distance, you can use an extension tube, which has a threaded slip-joint fitting on one end, and connect it between the wall tube and the J-trap. (I tried this first, then realized I didn't need all that vertical distance and could eliminate the extension tube.) If you find that it leaks after you tighten everything up, and you have water on top of the reducing washer on the tailpiece, it means your drain assembly isn't watertight against the sink.
You may need to tighten it (carefully, so as not to crack the sink) or remove it and apply more silicone or plumber's putty, along with Teflon tape on the threads. Two complementary L or angled connections (to move the drain laterally), plus loosening and rotating the trap around its connection to the pipe coming out of the wall... plus shortening the drain tailpiece and adding a bit of straight pipe, if necessary... ought to be able to complete the connection. Two overlapping circles will have two positions where they cross each other; at least one of them won't be blocked by the wall pipe. You cut the piece out by the wall, as far from the wall as you can. You need a female/female connection then a straight piece, then a 90 down then your trap. The only piece to cut is the straight piece. You need to cut it so when you angle your trap it is directly under the tail. Then just extend tail down. Sign up or log in Sign up using Google Sign up using Email and Password
Post as a guest By posting your answer, you agree to the privacy policy and terms of service. Not the answer you're looking for? Browse other questions tagged plumbing bathroom sink drain drain-waste-vent or ask your own question.Step 1: Materials and ToolsShow All Items How to Install a Bathroom SinkI have just removed my single sink vanity from my bathroom. I replaced it with a double sink vanity. I have water connections and drain for one sink rather than two seperate drains and waters connections for each sink. Are there shut off valves that allow for two water supply connections. Can I plumb the drains like the kitchen sink is plumbed. The main thing I want to avoid is having to run another drain and water supply. we are tired of brushing our teeth at the kitchen sink!! Not what you were looking for ?Welcome to the Home Depot Community! It’s quite common for there to be only 1 line each in a bathroom for the drain, cold and hot water. Yes, the drain can be plumbed like a double kitchen sink by converting the 1.25” sink flanges to a 1.5” and using a Tee below one of the bowls to join them.
There are also 1.25" flanged 90 elbows (shown below) that provide another way to accomplish this. The “P-Trap” will be placed below the pipes that join the bowls. How you actually design this will depend on where the wall drain is relative to the bowls. Any Home Depot plumbing associate can help you with this given a simple drawing of the bowl spread, and location of the wall drain. For the water supply, you can either use a Tee with 2 valves for each supply, or a simple double outlet valve like this: I hope this helps. The problem with using one drain line for the double sink replacement is always blockage of drain lines from vanity drawers, and each vanity is different. I have been successful with several ubgrades by simply removing the drawers, plumbing the drains then shortening the drawers needed to let the drains pass behind. Often only one drawer needs to be shortened. The process is to cut the back off straight with a table saw and then just replace the back of the drawer.
Sorry I am so lazy, but no issues so far.Welcome to the Community! I agree that there are times when drawers get in the way. In addition, the place allocated in the cabinet design for the wall drain may not be where the wall drain actually is. Vanities do vary in design. It will always be easier to modify the vanity cabinet to accommodate plumbing than to tear up the wall and move the outlet or add another one. I like your process for shortening drawers. It seems quick and easy. Thanks for the tip, Newf- I read a 2010 reply you posted for a user interested in installing a double sink for a bathroom vanity where currently only one existed. I am doing the same thing and found your post helpful. Two follow up questions: 1) does the second plumbing connection which will be connected to the first need to be vented or is the vent from the existing connection sufficient? 2) If I understand your previous answer, the new sink flange will also have a P trap that empties into the horizontal PVC pipe connecting to the Tee elbow.
Normally the venting for sinks is a vertical pipe inside the wall which leads from the drain up to the roof. It is not necessary for each basin to have its own vent, as you will tie both basins to that same wall drain. Only if you are starting with a stud wall and using separate wall drains will you need both to be vented. Even then you would simply tie the vents together at some level higher than the sink tops. How you do that depends on what is the easiest way given vanity layout, drawers and spacing between the basins. You can either tie the basins together before a single P trap like is often done with double kitchen sinks, or have each basin get its own trap and run their horizontals into a Tee or Wye fitting at the common wall drain. In addition, some installations would use a double Wye where the extra hub has a cleanout plug. Is this what you are looking for? Hello, I am planning out how to install a double vanity top to an existing single sink top plumbing configuration.