Help me install a sink!

January 2, 2010 5:48 AM

Help me install a sink!

Hi, I'm a plumbing n00b and I need some advice on installing a sink...

I'm dealing with this. Long story, but in the past a sink+vanity were removed from a washroom (not by me) and now I need to install a sink. I'm planning on installing a pedestal sink (sink comes in 2 pieces, a pedestal and a basin). I think I'm OK following the instructions to affix the pedestal to the floor and the basin to the wall.

My questions however deal with the plumbing. What do I need to do and how do I need to do it?

1. For the drain pipe coming out of the wall. The end is threaded, do I just find a u-shaped trap at the hardware store and screw it on?

2. this drain pipe end is 2" outer diameter, do these traps come in a standard size or do I need to find a specific one?

3. for attaching the trap to this pipe, does it just screw on? or do I need any epoxies or sealants?

4. for the basin, how do I connect the other end of the pipe to the drain hole? Will the pipe just come into the hole and I seal it with caulking? Or is there some other hardware that I need to add or install?

5. And again is this going to be a standard size, or do I need to size it?

Note that I am OK with not having a drain plug like this (you know, where there's a lever-thing behind the faucet that you pull up and it seals the drain with this plug). Those things usually clog up and they're nearly impossible to clean. (and yes I need to clean that sink, sorry for the grime)

6. I'm kind of concerned about clearance. This photo shows the pedestal in pretty well the position it'll need to be in. I'm concerned whether the pipes will have clearance. I suppose I'll only find this out once I get the trap+other pipes but if there is a clearance problem, what might be the next step?

Thanks and happy new year.

posted by thermonuclear.jive.turkey to Home & Garden (5 answers total)

1. Yes. Home Depot and similar stores will sell you kits, or you can buy all the pieces individually. What parts you need, and of what sizes, will depend on the angles and distances involved -- get the sink in and then buy these parts.

2. Yes, standard size.

3. No epoxy or sealant needed. The fittings screw together, or have gaskets that get compressed and seal. Remember, the drain pipe is not under pressure, so it's easy to maintain watertightness.

4. Again, buy a kit at the hardware store. There are a million how-to guides online; this one is for a kitchen sink, but the principle is the same (here's one for a pedestle sink, for example). You'll probably need a small can of plumber's putty, or the kit you buy may include some.

5. Standard sizes -- measure and buy a kit to match.

6. In your case, probably calling in a plumber to move the connections. If the clearance problems are just tiny, fractions of an inch, then things can probably bend. But if it means rearranging the actual piping in the wall (which I suspect is unlikely -- this stuff is really standardized) then you either need a plumber, or you need to buy some books on plumbing and the right tools, and go to town.
posted by Forktine at 6:31 AM on January 2, 2010

The threaded part that is coming out of the wall is actually part of your old P trap - is there any reason you can't resuse the rest of it?

I agree with everything that forktine says.

There are enough moving joints in a p trap that you should be able to articulate it to where you want it to be.
posted by davey_darling at 7:11 AM on January 2, 2010

1, 3: Normally you would get something like a P trap, which is comprised of two parts; a right-angle section of pipe with a thread on, and a u-shaped bit with nuts on both ends, which links the right-angle section to the bottom of the sink. The idea is you can unscrew the u-shaped bit to clean.

However, in your case you already seem to have the right-angle bit of pipe with a thread on, so you could just use the u-shaped bit of pipe (if you can get one that will reach where you want).

4. You need a basin waste, which provides a plughole in the basin and a threaded pipe under the basin. You screw your u-shaped bit of pipe to it.

6. If the position of the black threaded right-angle pipe is a problem, you could change it. However, it looks like it's solvent welded in place, so you'd have to hacksaw it off. Suffice to say, it would be easier if it did fit!
posted by Mike1024 at 8:08 AM on January 2, 2010

#3- I would use thread seal tape or pipe thread compound on the drain threads- just for added insurance.

I also recommend a trip to your local library or to purchase a copy of the Reader's Digest New Complete Do-It-Yourself Manual. That particular book has been very helpful for me as a home DIY'er.
posted by surfgator at 11:36 AM on January 2, 2010

surfgator writes "I would use thread seal tape or pipe thread compound on the drain threads- just for added insurance."

Don't add a sealant to these threads. They are either a compression or flare type seal (one of each actually) and thread sealant will interfere with their operation.

Another common DIY error aided and abetted by the big box borgs are flexible bellows drain pipes. These aren't legal for house plumbing as DVW pipes are required to be smooth.
posted by Mitheral at 12:53 PM on January 2, 2010