Designing Kitchens and Bathrooms - replacing bathroom sink

We have an ancient wallmount bathroom sink that is in desperate need of replacing. We want to replace it with a standard pedastal sink. First of all, we are not sure how to get the old sink off the wall, and secondly, can we install a pedastal sink without having to run a drain out the bottom?

Yes, you can install a pedastal sink without a drain through the floor. Just do a trap to the wall drain. The old pedastal sink may be simply hooked onto a wall-mounted bracket. Cut off water. Disconnect all pipes/drains. Then just find out how the sink is "secured", and remove it. Install the new sink. Good Luck!

Phoebe:

If you look under the bathroom sink, you'll probably find that it is mounted on steel hanger which screws to the wall. There will probably be a 2X12 nailed between the studs behind the sink, and the hanger is screwed into that 2X12. Normally, to remove the sink, you simply disconnect the hot and cold water supply from the faucet and disconnect the drain pipe. The sink should come off if you pull straight up on it.

If your existing sink has a chrome plated drain pipe under it, you may be headed for trouble. Chrome plated p-traps are notorious for corroding to the point where they are very weak. The chrome plated drain pipe that heads into the wall has a threaded brass bushing on it that screws into a 1 1/4 inch brass elbow in the wall. Most of the time that brass drain pipe will bend up or tear before the bushing will unscrew from the elboe in the wall. Be prepared to cut a hole in the wall under the sink to remove the old chrome plated drain pipe.

Phoebe, what Nestor posted about removing the sink from the wall is true. Once you have the plumbing disconnected, it will probably lift right off of the wall. However, don't let his caution about the "chrome plated drain pipe" scare you. It's true, brass drains DO corrode and are pretty fragile after about 10 to 15 years of use. HOWEVER< you're going to replace it all anyway!! Use PVC when you install the new lavy. Much cheaper to purchase, much easier to work with, and has a half life of about a million years! Granted, it isn't shiny, but you're gonna hide it anyway!!

Phoebe:

What Lefty said about replacing chrome plated brass with PVC or ABS is true. The stuff is easy to work with, lasts forever and plastic drains don't clog easy. (or AS easily anyhow)

However, it's the getting the old chrome trap out that's the kicker. It's soldered into a threaded collar that screws into a 1 1/4 inch elbow in the wall. (at least that's the way all of mine were) The problem is that once the chrome trap is corroded, about the only way to remove that collar is by cutting out the plaster or drywall under the sink and twisting on it with a large pair of channel lock pliers. On several occasions I've cut them out by cutting slots in the collar and chiseling it loose, and I've even resorted to unsoldering the elbow and replacing it with a new one that didn't have a threaded collar stuck in one end.

However, getting the thing out isn't the biggest problem. If push comes to shove you can unsolder it and solder a new one on like I did. The bigger problem is replacing the drywall under the sink. Getting the holes in the approximately correct locations is a nuisance, but do-able. Getting something to attach that piece of drywall to is a bit harder. Once you make a hole to get the threaded collar out, then the only decent way to patch that hole is to enlarge it to the nearest wall studs. However, you'll probably find that the hot and cold water supply pipes prevent you from attaching a nailer to the sides of the wall studs on either side of the hole you've made. Look at the difference in elevation between where the cold supply comes out of the wall for the toilet and the sink. The hot and cold water pipes to the sink will both come up between these studs making it difficult to attach anything to the studs to attach the drywall patch to. And, if you can cut the existing drywall down the middle of the stud, take out the existing screws and put in new screws right next to them on the part of the drywall that's still covering half the stud without making a mess of it, you're a better man than I am.

What a lot of plumbers here in Winnipeg do is simply leave the chrome plated drain pipe sticking out of the wall, cut it off with a hack saw and gently tighten a 1 1/4 inch Fernco coupling around it to connect an ABS drain to.

I'm not here to discourage ambition and initiative. I encourage you to do things around your house yourself to both save money and become independant. However, replacing an old chrome p-trap is not my idea of a good beginner's type project, and I expect all of the other knowledgeable people in this forum will agree on that point.

Does any one know how to repair drain connection from wall on lav basin in 30 y/o house?